Remove uses of box_syntax in rustc and tools

compiler/rustc_codegen_cranelift/example/alloc_example.rs

@@ -1,4 +1,4 @@
-#![feature(start, core_intrinsics, alloc_error_handler, box_syntax)]
+#![feature(start, core_intrinsics, alloc_error_handler)]
 #![no_std]
 
 extern crate alloc;
@@ -29,7 +29,7 @@ fn alloc_error_handler(_: alloc::alloc::Layout) -> ! {
 
 #[start]
 fn main(_argc: isize, _argv: *const *const u8) -> isize {
-    let world: Box<&str> = box "Hello World!\0";
+    let world: Box<&str> = Box::new("Hello World!\0");
     unsafe {
         puts(*world as *const str as *const u8);
     }

compiler/rustc_codegen_cranelift/example/mini_core_hello_world.rs

@@ -1,4 +1,4 @@
-#![feature(no_core, lang_items, never_type, linkage, extern_types, thread_local, box_syntax)]
+#![feature(no_core, lang_items, never_type, linkage, extern_types, thread_local)]
 #![no_core]
 #![allow(dead_code, non_camel_case_types)]
 
@@ -178,7 +178,7 @@ fn main() {
         let ptr: *const i8 = hello as *const [u8] as *const i8;
         puts(ptr);
 
-        let world: Box<&str> = box "World!\0";
+        let world: Box<&str> = Box::new("World!\0");
         puts(*world as *const str as *const i8);
         world as Box<dyn SomeTrait>;
 
@@ -238,10 +238,10 @@ fn main() {
         }
     }
 
-    let _ = box NoisyDrop {
+    let _ = Box::new(NoisyDrop {
         text: "Boxed outer got dropped!\0",
         inner: NoisyDropInner,
-    } as Box<dyn SomeTrait>;
+    }) as Box<dyn SomeTrait>;
 
     const FUNC_REF: Option<fn()> = Some(main);
     match FUNC_REF {

compiler/rustc_codegen_gcc/example/alloc_example.rs

@@ -1,4 +1,4 @@
-#![feature(start, box_syntax, core_intrinsics, alloc_error_handler, lang_items)]
+#![feature(start, core_intrinsics, alloc_error_handler, lang_items)]
 #![no_std]
 
 extern crate alloc;
@@ -38,7 +38,7 @@ unsafe extern "C" fn _Unwind_Resume() {
 
 #[start]
 fn main(_argc: isize, _argv: *const *const u8) -> isize {
-    let world: Box<&str> = box "Hello World!\0";
+    let world: Box<&str> = Box::new("Hello World!\0");
     unsafe {
         puts(*world as *const str as *const u8);
     }

compiler/rustc_codegen_gcc/example/mini_core_hello_world.rs

@@ -1,7 +1,7 @@
 // Adapted from https://github.com/sunfishcode/mir2cranelift/blob/master/rust-examples/nocore-hello-world.rs
 
 #![feature(
-    no_core, unboxed_closures, start, lang_items, box_syntax, never_type, linkage,
+    no_core, unboxed_closures, start, lang_items, never_type, linkage,
     extern_types, thread_local
 )]
 #![no_core]
@@ -163,7 +163,7 @@ fn main() {
         let ptr: *const u8 = hello as *const [u8] as *const u8;
         puts(ptr);
 
-        let world: Box<&str> = box "World!\0";
+        let world: Box<&str> = Box::new("World!\0");
         puts(*world as *const str as *const u8);
         world as Box<dyn SomeTrait>;
 
@@ -223,10 +223,10 @@ fn main() {
         }
     }
 
-    let _ = box NoisyDrop {
+    let _ = Box::new(NoisyDrop {
         text: "Boxed outer got dropped!\0",
         inner: NoisyDropInner,
-    } as Box<dyn SomeTrait>;
+    }) as Box<dyn SomeTrait>;
 
     const FUNC_REF: Option<fn()> = Some(main);
     #[allow(unreachable_code)]

compiler/rustc_codegen_gcc/example/mod_bench.rs

@@ -1,4 +1,4 @@
-#![feature(start, box_syntax, core_intrinsics, lang_items)]
+#![feature(start, core_intrinsics, lang_items)]
 #![no_std]
 
 #[link(name = "c")]

compiler/rustc_error_codes/src/error_codes/E0010.md

@@ -5,7 +5,5 @@ the heap at runtime, and therefore cannot be done at compile time.
 Erroneous code example:
 
 ```compile_fail,E0010
-#![feature(box_syntax)]
-
-const CON : Box<i32> = box 0;
+const CON : Vec<i32> = vec![1, 2, 3];
 ```

compiler/rustc_hir_pretty/src/lib.rs

@@ -1367,8 +1367,8 @@ impl<'a> State<'a> {
         self.ann.pre(self, AnnNode::Expr(expr));
         match expr.kind {
             hir::ExprKind::Box(expr) => {
-                self.word_space("box");
-                self.print_expr_maybe_paren(expr, parser::PREC_PREFIX);
+                self.word_space("Box::new");
+                self.print_call_post(std::slice::from_ref(expr));
             }
             hir::ExprKind::Array(exprs) => {
                 self.print_expr_vec(exprs);

compiler/rustc_lint/src/unused.rs

@@ -1371,7 +1371,6 @@ declare_lint_pass!(UnusedAllocation => [UNUSED_ALLOCATION]);
 impl<'tcx> LateLintPass<'tcx> for UnusedAllocation {
     fn check_expr(&mut self, cx: &LateContext<'_>, e: &hir::Expr<'_>) {
         match e.kind {
-            hir::ExprKind::Box(_) => {}
             hir::ExprKind::Call(path_expr, [_])
                 if let hir::ExprKind::Path(qpath) = &path_expr.kind
                 && let Some(did) = cx.qpath_res(qpath, path_expr.hir_id).opt_def_id()

compiler/rustc_mir_transform/src/large_enums.rs

@@ -158,10 +158,12 @@ impl EnumSizeOpt {
                             tmp_ty,
                         ),
                     };
-                    let rval = Rvalue::Use(Operand::Constant(box (constant_vals)));
+                    let rval = Rvalue::Use(Operand::Constant(Box::new(constant_vals)));
 
-                    let const_assign =
-                        Statement { source_info, kind: StatementKind::Assign(box (place, rval)) };
+                    let const_assign = Statement {
+                        source_info,
+                        kind: StatementKind::Assign(Box::new((place, rval))),
+                    };
 
                     let discr_place = Place::from(
                         local_decls
@@ -170,7 +172,10 @@ impl EnumSizeOpt {
 
                     let store_discr = Statement {
                         source_info,
-                        kind: StatementKind::Assign(box (discr_place, Rvalue::Discriminant(*rhs))),
+                        kind: StatementKind::Assign(Box::new((
+                            discr_place,
+                            Rvalue::Discriminant(*rhs),
+                        ))),
                     };
 
                     let discr_cast_place =
@@ -178,14 +183,14 @@ impl EnumSizeOpt {
 
                     let cast_discr = Statement {
                         source_info,
-                        kind: StatementKind::Assign(box (
+                        kind: StatementKind::Assign(Box::new((
                             discr_cast_place,
                             Rvalue::Cast(
                                 CastKind::IntToInt,
                                 Operand::Copy(discr_place),
                                 tcx.types.usize,
                             ),
-                        )),
+                        ))),
                     };
 
                     let size_place =
@@ -193,14 +198,14 @@ impl EnumSizeOpt {
 
                     let store_size = Statement {
                         source_info,
-                        kind: StatementKind::Assign(box (
+                        kind: StatementKind::Assign(Box::new((
                             size_place,
                             Rvalue::Use(Operand::Copy(Place {
                                 local: size_array_local,
                                 projection: tcx
                                     .mk_place_elems(&[PlaceElem::Index(discr_cast_place.local)]),
                             })),
-                        )),
+                        ))),
                     };
 
                     let dst =
@@ -208,10 +213,10 @@ impl EnumSizeOpt {
 
                     let dst_ptr = Statement {
                         source_info,
-                        kind: StatementKind::Assign(box (
+                        kind: StatementKind::Assign(Box::new((
                             dst,
                             Rvalue::AddressOf(Mutability::Mut, *lhs),
-                        )),
+                        ))),
                     };
 
                     let dst_cast_ty = tcx.mk_mut_ptr(tcx.types.u8);
@@ -220,10 +225,10 @@ impl EnumSizeOpt {
 
                     let dst_cast = Statement {
                         source_info,
-                        kind: StatementKind::Assign(box (
+                        kind: StatementKind::Assign(Box::new((
                             dst_cast_place,
                             Rvalue::Cast(CastKind::PtrToPtr, Operand::Copy(dst), dst_cast_ty),
-                        )),
+                        ))),
                     };
 
                     let src =
@@ -231,10 +236,10 @@ impl EnumSizeOpt {
 
                     let src_ptr = Statement {
                         source_info,
-                        kind: StatementKind::Assign(box (
+                        kind: StatementKind::Assign(Box::new((
                             src,
                             Rvalue::AddressOf(Mutability::Not, *rhs),
-                        )),
+                        ))),
                     };
 
                     let src_cast_ty = tcx.mk_imm_ptr(tcx.types.u8);
@@ -243,24 +248,24 @@ impl EnumSizeOpt {
 
                     let src_cast = Statement {
                         source_info,
-                        kind: StatementKind::Assign(box (
+                        kind: StatementKind::Assign(Box::new((
                             src_cast_place,
                             Rvalue::Cast(CastKind::PtrToPtr, Operand::Copy(src), src_cast_ty),
-                        )),
+                        ))),
                     };
 
                     let deinit_old =
-                        Statement { source_info, kind: StatementKind::Deinit(box dst) };
+                        Statement { source_info, kind: StatementKind::Deinit(Box::new(dst)) };
 
                     let copy_bytes = Statement {
                         source_info,
-                        kind: StatementKind::Intrinsic(
-                            box NonDivergingIntrinsic::CopyNonOverlapping(CopyNonOverlapping {
+                        kind: StatementKind::Intrinsic(Box::new(
+                            NonDivergingIntrinsic::CopyNonOverlapping(CopyNonOverlapping {
                                 src: Operand::Copy(src_cast_place),
                                 dst: Operand::Copy(dst_cast_place),
                                 count: Operand::Copy(size_place),
                             }),
-                        ),
+                        )),
                     };
 
                     let store_dead = Statement {

compiler/rustc_mir_transform/src/lib.rs

@@ -1,7 +1,6 @@
 #![allow(rustc::potential_query_instability)]
 #![feature(box_patterns)]
 #![feature(drain_filter)]
-#![feature(box_syntax)]
 #![feature(let_chains)]
 #![feature(map_try_insert)]
 #![feature(min_specialization)]

src/doc/unstable-book/src/the-unstable-book.md

@@ -5,16 +5,31 @@ each one organized by a "feature flag." That is, when using an unstable
 feature of Rust, you must use a flag, like this:
 
 ```rust
-#![feature(box_syntax)]
+#![feature(generators, generator_trait)]
+
+use std::ops::{Generator, GeneratorState};
+use std::pin::Pin;
 
 fn main() {
-    let five = box 5;
+    let mut generator = || {
+        yield 1;
+        return "foo"
+    };
+
+    match Pin::new(&mut generator).resume(()) {
+        GeneratorState::Yielded(1) => {}
+        _ => panic!("unexpected value from resume"),
+    }
+    match Pin::new(&mut generator).resume(()) {
+        GeneratorState::Complete("foo") => {}
+        _ => panic!("unexpected value from resume"),
+    }
 }
 ```
 
-The `box_syntax` feature [has a chapter][box] describing how to use it.
+The `generators` feature [has a chapter][generators] describing how to use it.
 
-[box]: language-features/box-syntax.md
+[generators]: language-features/generators.md
 
 Because this documentation relates to unstable features, we make no guarantees
 that what is contained here is accurate or up to date. It's developed on a

src/tools/clippy/tests/ui/boxed_local.rs

@@ -1,4 +1,3 @@
-#![feature(box_syntax)]
 #![feature(lint_reasons)]
 #![allow(
     clippy::borrowed_box,
@@ -34,7 +33,7 @@ fn ok_box_trait(boxed_trait: &Box<dyn Z>) {
 }
 
 fn warn_call() {
-    let x = box A;
+    let x = Box::new(A);
     x.foo();
 }
 
@@ -43,41 +42,41 @@ fn warn_arg(x: Box<A>) {
 }
 
 fn nowarn_closure_arg() {
-    let x = Some(box A);
+    let x = Some(Box::new(A));
     x.map_or((), |x| take_ref(&x));
 }
 
 fn warn_rename_call() {
-    let x = box A;
+    let x = Box::new(A);
 
     let y = x;
     y.foo(); // via autoderef
 }
 
 fn warn_notuse() {
-    let bz = box A;
+    let bz = Box::new(A);
 }
 
 fn warn_pass() {
-    let bz = box A;
+    let bz = Box::new(A);
     take_ref(&bz); // via deref coercion
 }
 
 fn nowarn_return() -> Box<A> {
-    box A // moved out, "escapes"
+    Box::new(A) // moved out, "escapes"
 }
 
 fn nowarn_move() {
-    let bx = box A;
+    let bx = Box::new(A);
     drop(bx) // moved in, "escapes"
 }
 fn nowarn_call() {
-    let bx = box A;
+    let bx = Box::new(A);
     bx.clone(); // method only available to Box, not via autoderef
 }
 
 fn nowarn_pass() {
-    let bx = box A;
+    let bx = Box::new(A);
     take_box(&bx); // fn needs &Box
 }
 
@@ -86,30 +85,20 @@ fn take_ref(x: &A) {}
 
 fn nowarn_ref_take() {
     // false positive, should actually warn
-    let x = box A;
+    let x = Box::new(A);
     let y = &x;
     take_box(y);
 }
 
 fn nowarn_match() {
-    let x = box A; // moved into a match
+    let x = Box::new(A); // moved into a match
     match x {
         y => drop(y),
     }
 }
 
 fn warn_match() {
-    let x = box A;
-    match &x {
-        // not moved
-        y => (),
-    }
-}
-
-fn nowarn_large_array() {
-    // should not warn, is large array
-    // and should not be on stack
-    let x = box [1; 10000];
+    let x = Box::new(A);
     match &x {
         // not moved
         y => (),

src/tools/clippy/tests/ui/boxed_local.stderr

@@ -1,5 +1,5 @@
 error: local variable doesn't need to be boxed here
-  --> $DIR/boxed_local.rs:41:13
+  --> $DIR/boxed_local.rs:40:13
    |
 LL | fn warn_arg(x: Box<A>) {
    |             ^
@@ -7,19 +7,19 @@ LL | fn warn_arg(x: Box<A>) {
    = note: `-D clippy::boxed-local` implied by `-D warnings`
 
 error: local variable doesn't need to be boxed here
-  --> $DIR/boxed_local.rs:132:12
+  --> $DIR/boxed_local.rs:121:12
    |
 LL | pub fn new(_needs_name: Box<PeekableSeekable<&()>>) -> () {}
    |            ^^^^^^^^^^^
 
 error: local variable doesn't need to be boxed here
-  --> $DIR/boxed_local.rs:196:44
+  --> $DIR/boxed_local.rs:185:44
    |
 LL |         fn default_impl_x(self: Box<Self>, x: Box<u32>) -> u32 {
    |                                            ^
 
 error: local variable doesn't need to be boxed here
-  --> $DIR/boxed_local.rs:203:16
+  --> $DIR/boxed_local.rs:192:16
    |
 LL |         fn foo(x: Box<u32>) {}
    |                ^

src/tools/clippy/tests/ui/no_effect.rs

@@ -1,4 +1,4 @@
-#![feature(box_syntax, fn_traits, unboxed_closures)]
+#![feature(fn_traits, unboxed_closures)]
 #![warn(clippy::no_effect_underscore_binding)]
 #![allow(dead_code, path_statements)]
 #![allow(clippy::deref_addrof, clippy::redundant_field_names, clippy::uninlined_format_args)]
@@ -102,7 +102,6 @@ fn main() {
     *&42;
     &6;
     (5, 6, 7);
-    box 42;
     ..;
     5..;
     ..5;

src/tools/clippy/tests/ui/no_effect.stderr

@@ -81,83 +81,77 @@ LL |     (5, 6, 7);
 error: statement with no effect
   --> $DIR/no_effect.rs:105:5
    |
-LL |     box 42;
-   |     ^^^^^^^
-
-error: statement with no effect
-  --> $DIR/no_effect.rs:106:5
-   |
 LL |     ..;
    |     ^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:107:5
+  --> $DIR/no_effect.rs:106:5
    |
 LL |     5..;
    |     ^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:108:5
+  --> $DIR/no_effect.rs:107:5
    |
 LL |     ..5;
    |     ^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:109:5
+  --> $DIR/no_effect.rs:108:5
    |
 LL |     5..6;
    |     ^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:110:5
+  --> $DIR/no_effect.rs:109:5
    |
 LL |     5..=6;
    |     ^^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:111:5
+  --> $DIR/no_effect.rs:110:5
    |
 LL |     [42, 55];
    |     ^^^^^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:112:5
+  --> $DIR/no_effect.rs:111:5
    |
 LL |     [42, 55][1];
    |     ^^^^^^^^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:113:5
+  --> $DIR/no_effect.rs:112:5
    |
 LL |     (42, 55).1;
    |     ^^^^^^^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:114:5
+  --> $DIR/no_effect.rs:113:5
    |
 LL |     [42; 55];
    |     ^^^^^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:115:5
+  --> $DIR/no_effect.rs:114:5
    |
 LL |     [42; 55][13];
    |     ^^^^^^^^^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:117:5
+  --> $DIR/no_effect.rs:116:5
    |
 LL |     || x += 5;
    |     ^^^^^^^^^^
 
 error: statement with no effect
-  --> $DIR/no_effect.rs:119:5
+  --> $DIR/no_effect.rs:118:5
    |
 LL |     FooString { s: s };
    |     ^^^^^^^^^^^^^^^^^^^
 
 error: binding to `_` prefixed variable with no side-effect
-  --> $DIR/no_effect.rs:120:5
+  --> $DIR/no_effect.rs:119:5
    |
 LL |     let _unused = 1;
    |     ^^^^^^^^^^^^^^^^
@@ -165,22 +159,22 @@ LL |     let _unused = 1;
    = note: `-D clippy::no-effect-underscore-binding` implied by `-D warnings`
 
 error: binding to `_` prefixed variable with no side-effect
-  --> $DIR/no_effect.rs:121:5
+  --> $DIR/no_effect.rs:120:5
    |
 LL |     let _penguin = || println!("Some helpful closure");
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: binding to `_` prefixed variable with no side-effect
-  --> $DIR/no_effect.rs:122:5
+  --> $DIR/no_effect.rs:121:5
    |
 LL |     let _duck = Struct { field: 0 };
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: binding to `_` prefixed variable with no side-effect
-  --> $DIR/no_effect.rs:123:5
+  --> $DIR/no_effect.rs:122:5
    |
 LL |     let _cat = [2, 4, 6, 8][2];
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 30 previous errors
+error: aborting due to 29 previous errors
 

src/tools/clippy/tests/ui/unnecessary_operation.fixed

@@ -1,6 +1,5 @@
 // run-rustfix
 
-#![feature(box_syntax)]
 #![allow(clippy::deref_addrof, dead_code, unused, clippy::no_effect)]
 #![warn(clippy::unnecessary_operation)]
 
@@ -59,7 +58,6 @@ fn main() {
     5;6;get_number();
     get_number();
     get_number();
-    get_number();
     5;get_number();
     42;get_number();
     assert!([42, 55].len() > get_usize());

src/tools/clippy/tests/ui/unnecessary_operation.rs

@@ -1,6 +1,5 @@
 // run-rustfix
 
-#![feature(box_syntax)]
 #![allow(clippy::deref_addrof, dead_code, unused, clippy::no_effect)]
 #![warn(clippy::unnecessary_operation)]
 
@@ -57,7 +56,6 @@ fn main() {
     *&get_number();
     &get_number();
     (5, 6, get_number());
-    box get_number();
     get_number()..;
     ..get_number();
     5..get_number();

src/tools/clippy/tests/ui/unnecessary_operation.stderr

@@ -1,5 +1,5 @@
 error: unnecessary operation
-  --> $DIR/unnecessary_operation.rs:51:5
+  --> $DIR/unnecessary_operation.rs:50:5
    |
 LL |     Tuple(get_number());
    |     ^^^^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `get_number();`
@@ -7,109 +7,103 @@ LL |     Tuple(get_number());
    = note: `-D clippy::unnecessary-operation` implied by `-D warnings`
 
 error: unnecessary operation
-  --> $DIR/unnecessary_operation.rs:52:5
+  --> $DIR/unnecessary_operation.rs:51:5
    |
 LL |     Struct { field: get_number() };
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `get_number();`
 
 error: unnecessary operation
-  --> $DIR/unnecessary_operation.rs:53:5
+  --> $DIR/unnecessary_operation.rs:52:5
    |
 LL |     Struct { ..get_struct() };
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `get_struct();`
 
 error: unnecessary operation
-  --> $DIR/unnecessary_operation.rs:54:5
+  --> $DIR/unnecessary_operation.rs:53:5
    |
 LL |     Enum::Tuple(get_number());
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `get_number();`
 
 error: unnecessary operation
-  --> $DIR/unnecessary_operation.rs:55:5
+  --> $DIR/unnecessary_operation.rs:54:5
    |
 LL |     Enum::Struct { field: get_number() };
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `get_number();`
 
 error: unnecessary operation
-  --> $DIR/unnecessary_operation.rs:56:5
+  --> $DIR/unnecessary_operation.rs:55:5
    |
 LL |     5 + get_number();
    |     ^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `5;get_number();`
 
 error: unnecessary operation
-  --> $DIR/unnecessary_operation.rs:57:5
+  --> $DIR/unnecessary_operation.rs:56:5
    |
 LL |     *&get_number();
    |     ^^^^^^^^^^^^^^^ help: statement can be reduced to: `get_number();`
 
 error: unnecessary operation
-  --> $DIR/unnecessary_operation.rs:58:5
+  --> $DIR/unnecessary_operation.rs:57:5
    |
 LL |     &get_number();
    |     ^^^^^^^^^^^^^^ help: statement can be reduced to: `get_number();`
 
 error: unnecessary operation
-  --> $DIR/unnecessary_operation.rs:59:5
+  --> $DIR/unnecessary_operation.rs:58:5
    |
 LL |     (5, 6, get_number());
    |     ^^^^^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `5;6;get_number();`
 
 error: unnecessary operation
-  --> $DIR/unnecessary_operation.rs:60:5
-   |
-LL |     box get_number();
-   |     ^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `get_number();`
-
-error: unnecessary operation
-  --> $DIR/unnecessary_operation.rs:61:5
+  --> $DIR/unnecessary_operation.rs:59:5
    |
 LL |     get_number()..;
    |     ^^^^^^^^^^^^^^^ help: statement can be reduced to: `get_number();`
 
 error: unnecessary operation
-  --> $DIR/unnecessary_operation.rs:62:5
+  --> $DIR/unnecessary_operation.rs:60:5
    |
 LL |     ..get_number();
    |     ^^^^^^^^^^^^^^^ help: statement can be reduced to: `get_number();`
 
 error: unnecessary operation
-  --> $DIR/unnecessary_operation.rs:63:5
+  --> $DIR/unnecessary_operation.rs:61:5
    |
 LL |     5..get_number();
    |     ^^^^^^^^^^^^^^^^ help: statement can be reduced to: `5;get_number();`
 
 error: unnecessary operation
-  --> $DIR/unnecessary_operation.rs:64:5
+  --> $DIR/unnecessary_operation.rs:62:5
    |
 LL |     [42, get_number()];
    |     ^^^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `42;get_number();`
 
 error: unnecessary operation
-  --> $DIR/unnecessary_operation.rs:65:5
+  --> $DIR/unnecessary_operation.rs:63:5
    |
 LL |     [42, 55][get_usize()];
    |     ^^^^^^^^^^^^^^^^^^^^^^ help: statement can be written as: `assert!([42, 55].len() > get_usize());`
 
 error: unnecessary operation
-  --> $DIR/unnecessary_operation.rs:66:5
+  --> $DIR/unnecessary_operation.rs:64:5
    |
 LL |     (42, get_number()).1;
    |     ^^^^^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `42;get_number();`
 
 error: unnecessary operation
-  --> $DIR/unnecessary_operation.rs:67:5
+  --> $DIR/unnecessary_operation.rs:65:5
    |
 LL |     [get_number(); 55];
    |     ^^^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `get_number();`
 
 error: unnecessary operation
-  --> $DIR/unnecessary_operation.rs:68:5
+  --> $DIR/unnecessary_operation.rs:66:5
    |
 LL |     [42; 55][get_usize()];
    |     ^^^^^^^^^^^^^^^^^^^^^^ help: statement can be written as: `assert!([42; 55].len() > get_usize());`
 
 error: unnecessary operation
-  --> $DIR/unnecessary_operation.rs:69:5
+  --> $DIR/unnecessary_operation.rs:67:5
    |
 LL | /     {
 LL | |         get_number()
@@ -117,12 +111,12 @@ LL | |     };
    | |______^ help: statement can be reduced to: `get_number();`
 
 error: unnecessary operation
-  --> $DIR/unnecessary_operation.rs:72:5
+  --> $DIR/unnecessary_operation.rs:70:5
    |
 LL | /     FooString {
 LL | |         s: String::from("blah"),
 LL | |     };
    | |______^ help: statement can be reduced to: `String::from("blah");`
 
-error: aborting due to 20 previous errors
+error: aborting due to 19 previous errors
 

src/tools/miri/tests/fail/function_pointers/execute_memory.rs

@@ -1,10 +1,8 @@
 // Validation makes this fail in the wrong place
 //@compile-flags: -Zmiri-disable-validation
 
-#![feature(box_syntax)]
-
 fn main() {
-    let x = box 42;
+    let x = Box::new(42);
     unsafe {
         let f = std::mem::transmute::<Box<i32>, fn()>(x);
         f() //~ ERROR: function pointer but it does not point to a function

src/tools/miri/tests/pass/drop_empty_slice.rs

@@ -1,7 +1,5 @@
-#![feature(box_syntax)]
-
 fn main() {
     // With the nested Vec, this is calling Offset(Unique::empty(), 0) on drop.
     let args: Vec<Vec<i32>> = Vec::new();
-    let _val = box args;
+    let _val = Box::new(args);
 }

src/tools/miri/tests/pass/dst-struct.rs

@@ -1,5 +1,3 @@
-#![feature(box_syntax)]
-
 struct Fat<T: ?Sized> {
     f1: isize,
     f2: &'static str,
@@ -109,7 +107,7 @@ pub fn main() {
     assert_eq!((*f2)[1], 2);
 
     // Nested Box.
-    let f1: Box<Fat<[isize; 3]>> = box Fat { f1: 5, f2: "some str", ptr: [1, 2, 3] };
+    let f1: Box<Fat<[isize; 3]>> = Box::new(Fat { f1: 5, f2: "some str", ptr: [1, 2, 3] });
     foo(&*f1);
     let f2: Box<Fat<[isize]>> = f1;
     foo(&*f2);
@@ -117,6 +115,6 @@ pub fn main() {
     let f3: Box<Fat<[isize]>> =
         Box::<Fat<[_; 3]>>::new(Fat { f1: 5, f2: "some str", ptr: [1, 2, 3] });
     foo(&*f3);
-    let f4: Box<Fat<[isize]>> = box Fat { f1: 5, f2: "some str", ptr: [1, 2, 3] };
+    let f4: Box<Fat<[isize]>> = Box::new(Fat { f1: 5, f2: "some str", ptr: [1, 2, 3] });
     foo(&*f4);
 }

src/tools/miri/tests/pass/heap.rs

@@ -1,13 +1,7 @@
-#![feature(box_syntax)]
-
 fn make_box() -> Box<(i16, i16)> {
     Box::new((1, 2))
 }
 
-fn make_box_syntax() -> Box<(i16, i16)> {
-    box (1, 2)
-}
-
 fn allocate_reallocate() {
     let mut s = String::new();
 
@@ -29,6 +23,5 @@ fn allocate_reallocate() {
 
 fn main() {
     assert_eq!(*make_box(), (1, 2));
-    assert_eq!(*make_box_syntax(), (1, 2));
     allocate_reallocate();
 }

src/tools/miri/tests/pass/issues/issue-3794.rs

@@ -1,5 +1,3 @@
-#![feature(box_syntax)]
-
 trait T {
     fn print(&self);
 }
@@ -25,7 +23,7 @@ fn print_s(s: &S) {
 }
 
 pub fn main() {
-    let s: Box<S> = box S { s: 5 };
+    let s: Box<S> = Box::new(S { s: 5 });
     print_s(&*s);
     let t: Box<dyn T> = s as Box<dyn T>;
     print_t(&*t);

src/tools/miri/tests/pass/move-arg-2-unique.rs

@@ -1,11 +1,9 @@
-#![feature(box_syntax)]
-
 fn test(foo: Box<Vec<isize>>) {
     assert_eq!((*foo)[0], 10);
 }
 
 pub fn main() {
-    let x = box vec![10];
+    let x = Box::new(vec![10]);
     // Test forgetting a local by move-in
     test(x);
 }

src/tools/miri/tests/pass/move-arg-3-unique.rs

@@ -1,7 +1,5 @@
-#![feature(box_syntax)]
-
 pub fn main() {
-    let x = box 10;
+    let x = Box::new(10);
     let y = x;
     assert_eq!(*y, 10);
 }

src/tools/miri/tests/pass/mpsc.rs

@@ -1,15 +1,13 @@
-#![feature(box_syntax)]
-
 use std::sync::mpsc::channel;
 
 pub fn main() {
     let (tx, rx) = channel::<Box<_>>();
-    tx.send(box 100).unwrap();
+    tx.send(Box::new(100)).unwrap();
     let v = rx.recv().unwrap();
-    assert_eq!(v, box 100);
+    assert_eq!(v, Box::new(100));
 
-    tx.send(box 101).unwrap();
-    tx.send(box 102).unwrap();
-    assert_eq!(rx.recv().unwrap(), box 101);
-    assert_eq!(rx.recv().unwrap(), box 102);
+    tx.send(Box::new(101)).unwrap();
+    tx.send(Box::new(102)).unwrap();
+    assert_eq!(rx.recv().unwrap(), Box::new(101));
+    assert_eq!(rx.recv().unwrap(), Box::new(102));
 }

src/tools/miri/tests/pass/regions-lifetime-nonfree-late-bound.rs

@@ -12,8 +12,6 @@
 // doing region-folding, when really all clients of the region-folding
 // case only want to see *free* lifetime variables, not bound ones.
 
-#![feature(box_syntax)]
-
 pub fn main() {
     fn explicit() {
         fn test<F>(_x: Option<Box<F>>)
@@ -21,7 +19,7 @@ pub fn main() {
             F: FnMut(Box<dyn for<'a> FnMut(&'a isize)>),
         {
         }
-        test(Some(box |_f: Box<dyn for<'a> FnMut(&'a isize)>| {}));
+        test(Some(Box::new(|_f: Box<dyn for<'a> FnMut(&'a isize)>| {})));
     }
 
     // The code below is shorthand for the code above (and more likely
@@ -32,7 +30,7 @@ pub fn main() {
             F: FnMut(Box<dyn FnMut(&isize)>),
         {
         }
-        test(Some(box |_f: Box<dyn FnMut(&isize)>| {}));
+        test(Some(Box::new(|_f: Box<dyn FnMut(&isize)>| {})));
     }
 
     explicit();

src/tools/rust-analyzer/crates/ide-completion/src/tests/attribute.rs

@@ -857,9 +857,9 @@ mod lint {
     #[test]
     fn lint_feature() {
         check_edit(
-            "box_syntax",
+            "box_patterns",
             r#"#[feature(box_$0)] struct Test;"#,
-            r#"#[feature(box_syntax)] struct Test;"#,
+            r#"#[feature(box_patterns)] struct Test;"#,
         )
     }
 

src/tools/rustfmt/tests/source/expr.rs

@@ -3,7 +3,6 @@
 // Test expressions
 
 fn foo() -> bool {
-    let boxed: Box<i32> = box   5;
     let referenced = &5 ;
 
     let very_long_variable_name = ( a +  first +   simple + test   );
@@ -132,12 +131,6 @@ fn qux() {
     }
 }
 
-fn issue227() {
-    {
-        let handler = box DocumentProgressHandler::new(addr, DocumentProgressTask::DOMContentLoaded);
-    }
-}
-
 fn issue184(source: &str) {
     for c in source.chars() {
         if index < 'a' {
@@ -413,10 +406,6 @@ fn issue2704() {
                                 .concat(&requires1)
                                 .concat(&requires2)
                                 .distinct_total());
-    let requires = requires.set(box requires0
-                                .concat(&requires1)
-                                .concat(&requires2)
-                                .distinct_total());
     let requires = requires.set(requires0
                                 .concat(&requires1)
                                 .concat(&requires2)

src/tools/rustfmt/tests/target/configs/combine_control_expr/false.rs

@@ -108,12 +108,6 @@ fn main() {
         bbbbbbbbbbbbbbbbbbbbbbbbbbbbbb,
     ));
 
-    // Box
-    foo(box Bar {
-        aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa,
-        bbbbbbbbbbbbbbbbbbbbbbbbbbbbbb,
-    });
-
     // Unary
     foo(!bar(
         aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa,

src/tools/rustfmt/tests/target/configs/combine_control_expr/true.rs

@@ -96,12 +96,6 @@ fn main() {
         bbbbbbbbbbbbbbbbbbbbbbbbbbbbbb,
     ));
 
-    // Box
-    foo(box Bar {
-        aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa,
-        bbbbbbbbbbbbbbbbbbbbbbbbbbbbbb,
-    });
-
     // Unary
     foo(!bar(
         aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa,

src/tools/rustfmt/tests/target/expr.rs

@@ -3,7 +3,6 @@
 // Test expressions
 
 fn foo() -> bool {
-    let boxed: Box<i32> = box 5;
     let referenced = &5;
 
     let very_long_variable_name = (a + first + simple + test);
@@ -179,13 +178,6 @@ fn qux() {
     }
 }
 
-fn issue227() {
-    {
-        let handler =
-            box DocumentProgressHandler::new(addr, DocumentProgressTask::DOMContentLoaded);
-    }
-}
-
 fn issue184(source: &str) {
     for c in source.chars() {
         if index < 'a' {
@@ -454,12 +446,6 @@ fn issue2704() {
             .concat(&requires2)
             .distinct_total(),
     );
-    let requires = requires.set(
-        box requires0
-            .concat(&requires1)
-            .concat(&requires2)
-            .distinct_total(),
-    );
     let requires = requires.set(
         requires0
             .concat(&requires1)

tests/mir-opt/box_expr.main.ElaborateDrops.before.mir

@@ -3,12 +3,12 @@
 fn main() -> () {
     let mut _0: ();                      // return place in scope 0 at $DIR/box_expr.rs:+0:11: +0:11
     let _1: std::boxed::Box<S>;          // in scope 0 at $DIR/box_expr.rs:+1:9: +1:10
-    let mut _2: usize;                   // in scope 0 at $DIR/box_expr.rs:+1:13: +1:25
-    let mut _3: usize;                   // in scope 0 at $DIR/box_expr.rs:+1:13: +1:25
-    let mut _4: *mut u8;                 // in scope 0 at $DIR/box_expr.rs:+1:13: +1:25
-    let mut _5: std::boxed::Box<S>;      // in scope 0 at $DIR/box_expr.rs:+1:13: +1:25
-    let _6: ();                          // in scope 0 at $DIR/box_expr.rs:+2:5: +2:12
-    let mut _7: std::boxed::Box<S>;      // in scope 0 at $DIR/box_expr.rs:+2:10: +2:11
+    let mut _2: usize;                   // in scope 0 at $DIR/box_expr.rs:+2:5: +2:23
+    let mut _3: usize;                   // in scope 0 at $DIR/box_expr.rs:+2:5: +2:23
+    let mut _4: *mut u8;                 // in scope 0 at $DIR/box_expr.rs:+2:5: +2:23
+    let mut _5: std::boxed::Box<S>;      // in scope 0 at $DIR/box_expr.rs:+2:5: +2:23
+    let _6: ();                          // in scope 0 at $DIR/box_expr.rs:+3:5: +3:12
+    let mut _7: std::boxed::Box<S>;      // in scope 0 at $DIR/box_expr.rs:+3:10: +3:11
     scope 1 {
         debug x => _1;                   // in scope 1 at $DIR/box_expr.rs:+1:9: +1:10
     }
@@ -17,64 +17,64 @@ fn main() -> () {
 
     bb0: {
         StorageLive(_1);                 // scope 0 at $DIR/box_expr.rs:+1:9: +1:10
-        _2 = SizeOf(S);                  // scope 2 at $DIR/box_expr.rs:+1:13: +1:25
-        _3 = AlignOf(S);                 // scope 2 at $DIR/box_expr.rs:+1:13: +1:25
-        _4 = alloc::alloc::exchange_malloc(move _2, move _3) -> bb1; // scope 2 at $DIR/box_expr.rs:+1:13: +1:25
+        _2 = SizeOf(S);                  // scope 2 at $DIR/box_expr.rs:+2:5: +2:23
+        _3 = AlignOf(S);                 // scope 2 at $DIR/box_expr.rs:+2:5: +2:23
+        _4 = alloc::alloc::exchange_malloc(move _2, move _3) -> bb1; // scope 2 at $DIR/box_expr.rs:+2:5: +2:23
                                          // mir::Constant
-                                         // + span: $DIR/box_expr.rs:7:13: 7:25
+                                         // + span: $DIR/box_expr.rs:8:5: 8:23
                                          // + literal: Const { ty: unsafe fn(usize, usize) -> *mut u8 {alloc::alloc::exchange_malloc}, val: Value(<ZST>) }
     }
 
     bb1: {
-        StorageLive(_5);                 // scope 0 at $DIR/box_expr.rs:+1:13: +1:25
-        _5 = ShallowInitBox(move _4, S); // scope 0 at $DIR/box_expr.rs:+1:13: +1:25
-        (*_5) = S::new() -> [return: bb2, unwind: bb8]; // scope 0 at $DIR/box_expr.rs:+1:17: +1:25
+        StorageLive(_5);                 // scope 0 at $DIR/box_expr.rs:+2:5: +2:23
+        _5 = ShallowInitBox(move _4, S); // scope 0 at $DIR/box_expr.rs:+2:5: +2:23
+        (*_5) = S::new() -> [return: bb2, unwind: bb8]; // scope 0 at $DIR/box_expr.rs:+2:14: +2:22
                                          // mir::Constant
-                                         // + span: $DIR/box_expr.rs:7:17: 7:23
+                                         // + span: $DIR/box_expr.rs:8:14: 8:20
                                          // + literal: Const { ty: fn() -> S {S::new}, val: Value(<ZST>) }
     }
 
     bb2: {
-        _1 = move _5;                    // scope 0 at $DIR/box_expr.rs:+1:13: +1:25
-        drop(_5) -> bb3;                 // scope 0 at $DIR/box_expr.rs:+1:24: +1:25
+        _1 = move _5;                    // scope 0 at $DIR/box_expr.rs:+2:5: +2:23
+        drop(_5) -> bb3;                 // scope 0 at $DIR/box_expr.rs:+2:22: +2:23
     }
 
     bb3: {
-        StorageDead(_5);                 // scope 0 at $DIR/box_expr.rs:+1:24: +1:25
-        StorageLive(_6);                 // scope 1 at $DIR/box_expr.rs:+2:5: +2:12
-        StorageLive(_7);                 // scope 1 at $DIR/box_expr.rs:+2:10: +2:11
-        _7 = move _1;                    // scope 1 at $DIR/box_expr.rs:+2:10: +2:11
-        _6 = std::mem::drop::<Box<S>>(move _7) -> [return: bb4, unwind: bb6]; // scope 1 at $DIR/box_expr.rs:+2:5: +2:12
+        StorageDead(_5);                 // scope 0 at $DIR/box_expr.rs:+2:22: +2:23
+        StorageLive(_6);                 // scope 1 at $DIR/box_expr.rs:+3:5: +3:12
+        StorageLive(_7);                 // scope 1 at $DIR/box_expr.rs:+3:10: +3:11
+        _7 = move _1;                    // scope 1 at $DIR/box_expr.rs:+3:10: +3:11
+        _6 = std::mem::drop::<Box<S>>(move _7) -> [return: bb4, unwind: bb6]; // scope 1 at $DIR/box_expr.rs:+3:5: +3:12
                                          // mir::Constant
-                                         // + span: $DIR/box_expr.rs:8:5: 8:9
+                                         // + span: $DIR/box_expr.rs:9:5: 9:9
                                          // + literal: Const { ty: fn(Box<S>) {std::mem::drop::<Box<S>>}, val: Value(<ZST>) }
     }
 
     bb4: {
-        StorageDead(_7);                 // scope 1 at $DIR/box_expr.rs:+2:11: +2:12
-        StorageDead(_6);                 // scope 1 at $DIR/box_expr.rs:+2:12: +2:13
-        _0 = const ();                   // scope 0 at $DIR/box_expr.rs:+0:11: +3:2
-        drop(_1) -> bb5;                 // scope 0 at $DIR/box_expr.rs:+3:1: +3:2
+        StorageDead(_7);                 // scope 1 at $DIR/box_expr.rs:+3:11: +3:12
+        StorageDead(_6);                 // scope 1 at $DIR/box_expr.rs:+3:12: +3:13
+        _0 = const ();                   // scope 0 at $DIR/box_expr.rs:+0:11: +4:2
+        drop(_1) -> bb5;                 // scope 0 at $DIR/box_expr.rs:+4:1: +4:2
     }
 
     bb5: {
-        StorageDead(_1);                 // scope 0 at $DIR/box_expr.rs:+3:1: +3:2
-        return;                          // scope 0 at $DIR/box_expr.rs:+3:2: +3:2
+        StorageDead(_1);                 // scope 0 at $DIR/box_expr.rs:+4:1: +4:2
+        return;                          // scope 0 at $DIR/box_expr.rs:+4:2: +4:2
     }
 
     bb6 (cleanup): {
-        drop(_7) -> bb7;                 // scope 1 at $DIR/box_expr.rs:+2:11: +2:12
+        drop(_7) -> bb7;                 // scope 1 at $DIR/box_expr.rs:+3:11: +3:12
     }
 
     bb7 (cleanup): {
-        drop(_1) -> bb9;                 // scope 0 at $DIR/box_expr.rs:+3:1: +3:2
+        drop(_1) -> bb9;                 // scope 0 at $DIR/box_expr.rs:+4:1: +4:2
     }
 
     bb8 (cleanup): {
-        drop(_5) -> bb9;                 // scope 0 at $DIR/box_expr.rs:+1:24: +1:25
+        drop(_5) -> bb9;                 // scope 0 at $DIR/box_expr.rs:+2:22: +2:23
     }
 
     bb9 (cleanup): {
-        resume;                          // scope 0 at $DIR/box_expr.rs:+0:1: +3:2
+        resume;                          // scope 0 at $DIR/box_expr.rs:+0:1: +4:2
     }
 }

tests/mir-opt/box_expr.rs

@@ -1,17 +1,20 @@
 // ignore-wasm32-bare compiled with panic=abort by default
 
-#![feature(box_syntax)]
+#![feature(rustc_attrs, stmt_expr_attributes)]
 
 // EMIT_MIR box_expr.main.ElaborateDrops.before.mir
 fn main() {
-    let x = box S::new();
+    let x = #[rustc_box]
+    Box::new(S::new());
     drop(x);
 }
 
 struct S;
 
 impl S {
-    fn new() -> Self { S }
+    fn new() -> Self {
+        S
+    }
 }
 
 impl Drop for S {

tests/mir-opt/building/uniform_array_move_out.move_out_by_subslice.built.after.mir

@@ -3,21 +3,21 @@
 fn move_out_by_subslice() -> () {
     let mut _0: ();                      // return place in scope 0 at $DIR/uniform_array_move_out.rs:+0:27: +0:27
     let _1: [std::boxed::Box<i32>; 2];   // in scope 0 at $DIR/uniform_array_move_out.rs:+1:9: +1:10
-    let mut _2: std::boxed::Box<i32>;    // in scope 0 at $DIR/uniform_array_move_out.rs:+1:14: +1:19
-    let mut _3: usize;                   // in scope 0 at $DIR/uniform_array_move_out.rs:+1:14: +1:19
-    let mut _4: usize;                   // in scope 0 at $DIR/uniform_array_move_out.rs:+1:14: +1:19
-    let mut _5: *mut u8;                 // in scope 0 at $DIR/uniform_array_move_out.rs:+1:14: +1:19
-    let mut _6: std::boxed::Box<i32>;    // in scope 0 at $DIR/uniform_array_move_out.rs:+1:14: +1:19
-    let mut _7: std::boxed::Box<i32>;    // in scope 0 at $DIR/uniform_array_move_out.rs:+1:21: +1:26
-    let mut _8: usize;                   // in scope 0 at $DIR/uniform_array_move_out.rs:+1:21: +1:26
-    let mut _9: usize;                   // in scope 0 at $DIR/uniform_array_move_out.rs:+1:21: +1:26
-    let mut _10: *mut u8;                // in scope 0 at $DIR/uniform_array_move_out.rs:+1:21: +1:26
-    let mut _11: std::boxed::Box<i32>;   // in scope 0 at $DIR/uniform_array_move_out.rs:+1:21: +1:26
+    let mut _2: std::boxed::Box<i32>;    // in scope 0 at $DIR/uniform_array_move_out.rs:+3:9: +3:20
+    let mut _3: usize;                   // in scope 0 at $DIR/uniform_array_move_out.rs:+3:9: +3:20
+    let mut _4: usize;                   // in scope 0 at $DIR/uniform_array_move_out.rs:+3:9: +3:20
+    let mut _5: *mut u8;                 // in scope 0 at $DIR/uniform_array_move_out.rs:+3:9: +3:20
+    let mut _6: std::boxed::Box<i32>;    // in scope 0 at $DIR/uniform_array_move_out.rs:+3:9: +3:20
+    let mut _7: std::boxed::Box<i32>;    // in scope 0 at $DIR/uniform_array_move_out.rs:+5:9: +5:20
+    let mut _8: usize;                   // in scope 0 at $DIR/uniform_array_move_out.rs:+5:9: +5:20
+    let mut _9: usize;                   // in scope 0 at $DIR/uniform_array_move_out.rs:+5:9: +5:20
+    let mut _10: *mut u8;                // in scope 0 at $DIR/uniform_array_move_out.rs:+5:9: +5:20
+    let mut _11: std::boxed::Box<i32>;   // in scope 0 at $DIR/uniform_array_move_out.rs:+5:9: +5:20
     scope 1 {
         debug a => _1;                   // in scope 1 at $DIR/uniform_array_move_out.rs:+1:9: +1:10
-        let _12: [std::boxed::Box<i32>; 2]; // in scope 1 at $DIR/uniform_array_move_out.rs:+2:10: +2:12
+        let _12: [std::boxed::Box<i32>; 2]; // in scope 1 at $DIR/uniform_array_move_out.rs:+7:10: +7:12
         scope 4 {
-            debug _y => _12;             // in scope 4 at $DIR/uniform_array_move_out.rs:+2:10: +2:12
+            debug _y => _12;             // in scope 4 at $DIR/uniform_array_move_out.rs:+7:10: +7:12
         }
     }
     scope 2 {
@@ -27,86 +27,86 @@ fn move_out_by_subslice() -> () {
 
     bb0: {
         StorageLive(_1);                 // scope 0 at $DIR/uniform_array_move_out.rs:+1:9: +1:10
-        StorageLive(_2);                 // scope 0 at $DIR/uniform_array_move_out.rs:+1:14: +1:19
-        _3 = SizeOf(i32);                // scope 2 at $DIR/uniform_array_move_out.rs:+1:14: +1:19
-        _4 = AlignOf(i32);               // scope 2 at $DIR/uniform_array_move_out.rs:+1:14: +1:19
-        _5 = alloc::alloc::exchange_malloc(move _3, move _4) -> [return: bb1, unwind: bb12]; // scope 2 at $DIR/uniform_array_move_out.rs:+1:14: +1:19
+        StorageLive(_2);                 // scope 0 at $DIR/uniform_array_move_out.rs:+3:9: +3:20
+        _3 = SizeOf(i32);                // scope 2 at $DIR/uniform_array_move_out.rs:+3:9: +3:20
+        _4 = AlignOf(i32);               // scope 2 at $DIR/uniform_array_move_out.rs:+3:9: +3:20
+        _5 = alloc::alloc::exchange_malloc(move _3, move _4) -> [return: bb1, unwind: bb12]; // scope 2 at $DIR/uniform_array_move_out.rs:+3:9: +3:20
                                          // mir::Constant
-                                         // + span: $DIR/uniform_array_move_out.rs:11:14: 11:19
+                                         // + span: $DIR/uniform_array_move_out.rs:18:9: 18:20
                                          // + literal: Const { ty: unsafe fn(usize, usize) -> *mut u8 {alloc::alloc::exchange_malloc}, val: Value(<ZST>) }
     }
 
     bb1: {
-        StorageLive(_6);                 // scope 0 at $DIR/uniform_array_move_out.rs:+1:14: +1:19
-        _6 = ShallowInitBox(move _5, i32); // scope 0 at $DIR/uniform_array_move_out.rs:+1:14: +1:19
-        (*_6) = const 1_i32;             // scope 0 at $DIR/uniform_array_move_out.rs:+1:18: +1:19
-        _2 = move _6;                    // scope 0 at $DIR/uniform_array_move_out.rs:+1:14: +1:19
-        drop(_6) -> [return: bb2, unwind: bb11]; // scope 0 at $DIR/uniform_array_move_out.rs:+1:18: +1:19
+        StorageLive(_6);                 // scope 0 at $DIR/uniform_array_move_out.rs:+3:9: +3:20
+        _6 = ShallowInitBox(move _5, i32); // scope 0 at $DIR/uniform_array_move_out.rs:+3:9: +3:20
+        (*_6) = const 1_i32;             // scope 0 at $DIR/uniform_array_move_out.rs:+3:18: +3:19
+        _2 = move _6;                    // scope 0 at $DIR/uniform_array_move_out.rs:+3:9: +3:20
+        drop(_6) -> [return: bb2, unwind: bb11]; // scope 0 at $DIR/uniform_array_move_out.rs:+3:19: +3:20
     }
 
     bb2: {
-        StorageDead(_6);                 // scope 0 at $DIR/uniform_array_move_out.rs:+1:18: +1:19
-        StorageLive(_7);                 // scope 0 at $DIR/uniform_array_move_out.rs:+1:21: +1:26
-        _8 = SizeOf(i32);                // scope 3 at $DIR/uniform_array_move_out.rs:+1:21: +1:26
-        _9 = AlignOf(i32);               // scope 3 at $DIR/uniform_array_move_out.rs:+1:21: +1:26
-        _10 = alloc::alloc::exchange_malloc(move _8, move _9) -> [return: bb3, unwind: bb11]; // scope 3 at $DIR/uniform_array_move_out.rs:+1:21: +1:26
+        StorageDead(_6);                 // scope 0 at $DIR/uniform_array_move_out.rs:+3:19: +3:20
+        StorageLive(_7);                 // scope 0 at $DIR/uniform_array_move_out.rs:+5:9: +5:20
+        _8 = SizeOf(i32);                // scope 3 at $DIR/uniform_array_move_out.rs:+5:9: +5:20
+        _9 = AlignOf(i32);               // scope 3 at $DIR/uniform_array_move_out.rs:+5:9: +5:20
+        _10 = alloc::alloc::exchange_malloc(move _8, move _9) -> [return: bb3, unwind: bb11]; // scope 3 at $DIR/uniform_array_move_out.rs:+5:9: +5:20
                                          // mir::Constant
-                                         // + span: $DIR/uniform_array_move_out.rs:11:21: 11:26
+                                         // + span: $DIR/uniform_array_move_out.rs:20:9: 20:20
                                          // + literal: Const { ty: unsafe fn(usize, usize) -> *mut u8 {alloc::alloc::exchange_malloc}, val: Value(<ZST>) }
     }
 
     bb3: {
-        StorageLive(_11);                // scope 0 at $DIR/uniform_array_move_out.rs:+1:21: +1:26
-        _11 = ShallowInitBox(move _10, i32); // scope 0 at $DIR/uniform_array_move_out.rs:+1:21: +1:26
-        (*_11) = const 2_i32;            // scope 0 at $DIR/uniform_array_move_out.rs:+1:25: +1:26
-        _7 = move _11;                   // scope 0 at $DIR/uniform_array_move_out.rs:+1:21: +1:26
-        drop(_11) -> [return: bb4, unwind: bb10]; // scope 0 at $DIR/uniform_array_move_out.rs:+1:25: +1:26
+        StorageLive(_11);                // scope 0 at $DIR/uniform_array_move_out.rs:+5:9: +5:20
+        _11 = ShallowInitBox(move _10, i32); // scope 0 at $DIR/uniform_array_move_out.rs:+5:9: +5:20
+        (*_11) = const 2_i32;            // scope 0 at $DIR/uniform_array_move_out.rs:+5:18: +5:19
+        _7 = move _11;                   // scope 0 at $DIR/uniform_array_move_out.rs:+5:9: +5:20
+        drop(_11) -> [return: bb4, unwind: bb10]; // scope 0 at $DIR/uniform_array_move_out.rs:+5:19: +5:20
     }
 
     bb4: {
-        StorageDead(_11);                // scope 0 at $DIR/uniform_array_move_out.rs:+1:25: +1:26
-        _1 = [move _2, move _7];         // scope 0 at $DIR/uniform_array_move_out.rs:+1:13: +1:27
-        drop(_7) -> [return: bb5, unwind: bb11]; // scope 0 at $DIR/uniform_array_move_out.rs:+1:26: +1:27
+        StorageDead(_11);                // scope 0 at $DIR/uniform_array_move_out.rs:+5:19: +5:20
+        _1 = [move _2, move _7];         // scope 0 at $DIR/uniform_array_move_out.rs:+1:13: +6:6
+        drop(_7) -> [return: bb5, unwind: bb11]; // scope 0 at $DIR/uniform_array_move_out.rs:+6:5: +6:6
     }
 
     bb5: {
-        StorageDead(_7);                 // scope 0 at $DIR/uniform_array_move_out.rs:+1:26: +1:27
-        drop(_2) -> [return: bb6, unwind: bb12]; // scope 0 at $DIR/uniform_array_move_out.rs:+1:26: +1:27
+        StorageDead(_7);                 // scope 0 at $DIR/uniform_array_move_out.rs:+6:5: +6:6
+        drop(_2) -> [return: bb6, unwind: bb12]; // scope 0 at $DIR/uniform_array_move_out.rs:+6:5: +6:6
     }
 
     bb6: {
-        StorageDead(_2);                 // scope 0 at $DIR/uniform_array_move_out.rs:+1:26: +1:27
+        StorageDead(_2);                 // scope 0 at $DIR/uniform_array_move_out.rs:+6:5: +6:6
         FakeRead(ForLet(None), _1);      // scope 0 at $DIR/uniform_array_move_out.rs:+1:9: +1:10
-        PlaceMention(_1);                // scope 1 at $DIR/uniform_array_move_out.rs:+2:21: +2:22
-        StorageLive(_12);                // scope 1 at $DIR/uniform_array_move_out.rs:+2:10: +2:12
-        _12 = move _1[0..2];             // scope 1 at $DIR/uniform_array_move_out.rs:+2:10: +2:12
-        _0 = const ();                   // scope 0 at $DIR/uniform_array_move_out.rs:+0:27: +3:2
-        drop(_12) -> [return: bb7, unwind: bb9]; // scope 1 at $DIR/uniform_array_move_out.rs:+3:1: +3:2
+        PlaceMention(_1);                // scope 1 at $DIR/uniform_array_move_out.rs:+7:21: +7:22
+        StorageLive(_12);                // scope 1 at $DIR/uniform_array_move_out.rs:+7:10: +7:12
+        _12 = move _1[0..2];             // scope 1 at $DIR/uniform_array_move_out.rs:+7:10: +7:12
+        _0 = const ();                   // scope 0 at $DIR/uniform_array_move_out.rs:+0:27: +8:2
+        drop(_12) -> [return: bb7, unwind: bb9]; // scope 1 at $DIR/uniform_array_move_out.rs:+8:1: +8:2
     }
 
     bb7: {
-        StorageDead(_12);                // scope 1 at $DIR/uniform_array_move_out.rs:+3:1: +3:2
-        drop(_1) -> [return: bb8, unwind: bb12]; // scope 0 at $DIR/uniform_array_move_out.rs:+3:1: +3:2
+        StorageDead(_12);                // scope 1 at $DIR/uniform_array_move_out.rs:+8:1: +8:2
+        drop(_1) -> [return: bb8, unwind: bb12]; // scope 0 at $DIR/uniform_array_move_out.rs:+8:1: +8:2
     }
 
     bb8: {
-        StorageDead(_1);                 // scope 0 at $DIR/uniform_array_move_out.rs:+3:1: +3:2
-        return;                          // scope 0 at $DIR/uniform_array_move_out.rs:+3:2: +3:2
+        StorageDead(_1);                 // scope 0 at $DIR/uniform_array_move_out.rs:+8:1: +8:2
+        return;                          // scope 0 at $DIR/uniform_array_move_out.rs:+8:2: +8:2
     }
 
     bb9 (cleanup): {
-        drop(_1) -> bb12;                // scope 0 at $DIR/uniform_array_move_out.rs:+3:1: +3:2
+        drop(_1) -> bb12;                // scope 0 at $DIR/uniform_array_move_out.rs:+8:1: +8:2
     }
 
     bb10 (cleanup): {
-        drop(_7) -> bb11;                // scope 0 at $DIR/uniform_array_move_out.rs:+1:26: +1:27
+        drop(_7) -> bb11;                // scope 0 at $DIR/uniform_array_move_out.rs:+6:5: +6:6
     }
 
     bb11 (cleanup): {
-        drop(_2) -> bb12;                // scope 0 at $DIR/uniform_array_move_out.rs:+1:26: +1:27
+        drop(_2) -> bb12;                // scope 0 at $DIR/uniform_array_move_out.rs:+6:5: +6:6
     }
 
     bb12 (cleanup): {
-        resume;                          // scope 0 at $DIR/uniform_array_move_out.rs:+0:1: +3:2
+        resume;                          // scope 0 at $DIR/uniform_array_move_out.rs:+0:1: +8:2
     }
 }

tests/mir-opt/building/uniform_array_move_out.move_out_from_end.built.after.mir

@@ -3,21 +3,21 @@
 fn move_out_from_end() -> () {
     let mut _0: ();                      // return place in scope 0 at $DIR/uniform_array_move_out.rs:+0:24: +0:24
     let _1: [std::boxed::Box<i32>; 2];   // in scope 0 at $DIR/uniform_array_move_out.rs:+1:9: +1:10
-    let mut _2: std::boxed::Box<i32>;    // in scope 0 at $DIR/uniform_array_move_out.rs:+1:14: +1:19
-    let mut _3: usize;                   // in scope 0 at $DIR/uniform_array_move_out.rs:+1:14: +1:19
-    let mut _4: usize;                   // in scope 0 at $DIR/uniform_array_move_out.rs:+1:14: +1:19
-    let mut _5: *mut u8;                 // in scope 0 at $DIR/uniform_array_move_out.rs:+1:14: +1:19
-    let mut _6: std::boxed::Box<i32>;    // in scope 0 at $DIR/uniform_array_move_out.rs:+1:14: +1:19
-    let mut _7: std::boxed::Box<i32>;    // in scope 0 at $DIR/uniform_array_move_out.rs:+1:21: +1:26
-    let mut _8: usize;                   // in scope 0 at $DIR/uniform_array_move_out.rs:+1:21: +1:26
-    let mut _9: usize;                   // in scope 0 at $DIR/uniform_array_move_out.rs:+1:21: +1:26
-    let mut _10: *mut u8;                // in scope 0 at $DIR/uniform_array_move_out.rs:+1:21: +1:26
-    let mut _11: std::boxed::Box<i32>;   // in scope 0 at $DIR/uniform_array_move_out.rs:+1:21: +1:26
+    let mut _2: std::boxed::Box<i32>;    // in scope 0 at $DIR/uniform_array_move_out.rs:+3:9: +3:20
+    let mut _3: usize;                   // in scope 0 at $DIR/uniform_array_move_out.rs:+3:9: +3:20
+    let mut _4: usize;                   // in scope 0 at $DIR/uniform_array_move_out.rs:+3:9: +3:20
+    let mut _5: *mut u8;                 // in scope 0 at $DIR/uniform_array_move_out.rs:+3:9: +3:20
+    let mut _6: std::boxed::Box<i32>;    // in scope 0 at $DIR/uniform_array_move_out.rs:+3:9: +3:20
+    let mut _7: std::boxed::Box<i32>;    // in scope 0 at $DIR/uniform_array_move_out.rs:+5:9: +5:20
+    let mut _8: usize;                   // in scope 0 at $DIR/uniform_array_move_out.rs:+5:9: +5:20
+    let mut _9: usize;                   // in scope 0 at $DIR/uniform_array_move_out.rs:+5:9: +5:20
+    let mut _10: *mut u8;                // in scope 0 at $DIR/uniform_array_move_out.rs:+5:9: +5:20
+    let mut _11: std::boxed::Box<i32>;   // in scope 0 at $DIR/uniform_array_move_out.rs:+5:9: +5:20
     scope 1 {
         debug a => _1;                   // in scope 1 at $DIR/uniform_array_move_out.rs:+1:9: +1:10
-        let _12: std::boxed::Box<i32>;   // in scope 1 at $DIR/uniform_array_move_out.rs:+2:14: +2:16
+        let _12: std::boxed::Box<i32>;   // in scope 1 at $DIR/uniform_array_move_out.rs:+7:14: +7:16
         scope 4 {
-            debug _y => _12;             // in scope 4 at $DIR/uniform_array_move_out.rs:+2:14: +2:16
+            debug _y => _12;             // in scope 4 at $DIR/uniform_array_move_out.rs:+7:14: +7:16
         }
     }
     scope 2 {
@@ -27,86 +27,86 @@ fn move_out_from_end() -> () {
 
     bb0: {
         StorageLive(_1);                 // scope 0 at $DIR/uniform_array_move_out.rs:+1:9: +1:10
-        StorageLive(_2);                 // scope 0 at $DIR/uniform_array_move_out.rs:+1:14: +1:19
-        _3 = SizeOf(i32);                // scope 2 at $DIR/uniform_array_move_out.rs:+1:14: +1:19
-        _4 = AlignOf(i32);               // scope 2 at $DIR/uniform_array_move_out.rs:+1:14: +1:19
-        _5 = alloc::alloc::exchange_malloc(move _3, move _4) -> [return: bb1, unwind: bb12]; // scope 2 at $DIR/uniform_array_move_out.rs:+1:14: +1:19
+        StorageLive(_2);                 // scope 0 at $DIR/uniform_array_move_out.rs:+3:9: +3:20
+        _3 = SizeOf(i32);                // scope 2 at $DIR/uniform_array_move_out.rs:+3:9: +3:20
+        _4 = AlignOf(i32);               // scope 2 at $DIR/uniform_array_move_out.rs:+3:9: +3:20
+        _5 = alloc::alloc::exchange_malloc(move _3, move _4) -> [return: bb1, unwind: bb12]; // scope 2 at $DIR/uniform_array_move_out.rs:+3:9: +3:20
                                          // mir::Constant
-                                         // + span: $DIR/uniform_array_move_out.rs:5:14: 5:19
+                                         // + span: $DIR/uniform_array_move_out.rs:7:9: 7:20
                                          // + literal: Const { ty: unsafe fn(usize, usize) -> *mut u8 {alloc::alloc::exchange_malloc}, val: Value(<ZST>) }
     }
 
     bb1: {
-        StorageLive(_6);                 // scope 0 at $DIR/uniform_array_move_out.rs:+1:14: +1:19
-        _6 = ShallowInitBox(move _5, i32); // scope 0 at $DIR/uniform_array_move_out.rs:+1:14: +1:19
-        (*_6) = const 1_i32;             // scope 0 at $DIR/uniform_array_move_out.rs:+1:18: +1:19
-        _2 = move _6;                    // scope 0 at $DIR/uniform_array_move_out.rs:+1:14: +1:19
-        drop(_6) -> [return: bb2, unwind: bb11]; // scope 0 at $DIR/uniform_array_move_out.rs:+1:18: +1:19
+        StorageLive(_6);                 // scope 0 at $DIR/uniform_array_move_out.rs:+3:9: +3:20
+        _6 = ShallowInitBox(move _5, i32); // scope 0 at $DIR/uniform_array_move_out.rs:+3:9: +3:20
+        (*_6) = const 1_i32;             // scope 0 at $DIR/uniform_array_move_out.rs:+3:18: +3:19
+        _2 = move _6;                    // scope 0 at $DIR/uniform_array_move_out.rs:+3:9: +3:20
+        drop(_6) -> [return: bb2, unwind: bb11]; // scope 0 at $DIR/uniform_array_move_out.rs:+3:19: +3:20
     }
 
     bb2: {
-        StorageDead(_6);                 // scope 0 at $DIR/uniform_array_move_out.rs:+1:18: +1:19
-        StorageLive(_7);                 // scope 0 at $DIR/uniform_array_move_out.rs:+1:21: +1:26
-        _8 = SizeOf(i32);                // scope 3 at $DIR/uniform_array_move_out.rs:+1:21: +1:26
-        _9 = AlignOf(i32);               // scope 3 at $DIR/uniform_array_move_out.rs:+1:21: +1:26
-        _10 = alloc::alloc::exchange_malloc(move _8, move _9) -> [return: bb3, unwind: bb11]; // scope 3 at $DIR/uniform_array_move_out.rs:+1:21: +1:26
+        StorageDead(_6);                 // scope 0 at $DIR/uniform_array_move_out.rs:+3:19: +3:20
+        StorageLive(_7);                 // scope 0 at $DIR/uniform_array_move_out.rs:+5:9: +5:20
+        _8 = SizeOf(i32);                // scope 3 at $DIR/uniform_array_move_out.rs:+5:9: +5:20
+        _9 = AlignOf(i32);               // scope 3 at $DIR/uniform_array_move_out.rs:+5:9: +5:20
+        _10 = alloc::alloc::exchange_malloc(move _8, move _9) -> [return: bb3, unwind: bb11]; // scope 3 at $DIR/uniform_array_move_out.rs:+5:9: +5:20
                                          // mir::Constant
-                                         // + span: $DIR/uniform_array_move_out.rs:5:21: 5:26
+                                         // + span: $DIR/uniform_array_move_out.rs:9:9: 9:20
                                          // + literal: Const { ty: unsafe fn(usize, usize) -> *mut u8 {alloc::alloc::exchange_malloc}, val: Value(<ZST>) }
     }
 
     bb3: {
-        StorageLive(_11);                // scope 0 at $DIR/uniform_array_move_out.rs:+1:21: +1:26
-        _11 = ShallowInitBox(move _10, i32); // scope 0 at $DIR/uniform_array_move_out.rs:+1:21: +1:26
-        (*_11) = const 2_i32;            // scope 0 at $DIR/uniform_array_move_out.rs:+1:25: +1:26
-        _7 = move _11;                   // scope 0 at $DIR/uniform_array_move_out.rs:+1:21: +1:26
-        drop(_11) -> [return: bb4, unwind: bb10]; // scope 0 at $DIR/uniform_array_move_out.rs:+1:25: +1:26
+        StorageLive(_11);                // scope 0 at $DIR/uniform_array_move_out.rs:+5:9: +5:20
+        _11 = ShallowInitBox(move _10, i32); // scope 0 at $DIR/uniform_array_move_out.rs:+5:9: +5:20
+        (*_11) = const 2_i32;            // scope 0 at $DIR/uniform_array_move_out.rs:+5:18: +5:19
+        _7 = move _11;                   // scope 0 at $DIR/uniform_array_move_out.rs:+5:9: +5:20
+        drop(_11) -> [return: bb4, unwind: bb10]; // scope 0 at $DIR/uniform_array_move_out.rs:+5:19: +5:20
     }
 
     bb4: {
-        StorageDead(_11);                // scope 0 at $DIR/uniform_array_move_out.rs:+1:25: +1:26
-        _1 = [move _2, move _7];         // scope 0 at $DIR/uniform_array_move_out.rs:+1:13: +1:27
-        drop(_7) -> [return: bb5, unwind: bb11]; // scope 0 at $DIR/uniform_array_move_out.rs:+1:26: +1:27
+        StorageDead(_11);                // scope 0 at $DIR/uniform_array_move_out.rs:+5:19: +5:20
+        _1 = [move _2, move _7];         // scope 0 at $DIR/uniform_array_move_out.rs:+1:13: +6:6
+        drop(_7) -> [return: bb5, unwind: bb11]; // scope 0 at $DIR/uniform_array_move_out.rs:+6:5: +6:6
     }
 
     bb5: {
-        StorageDead(_7);                 // scope 0 at $DIR/uniform_array_move_out.rs:+1:26: +1:27
-        drop(_2) -> [return: bb6, unwind: bb12]; // scope 0 at $DIR/uniform_array_move_out.rs:+1:26: +1:27
+        StorageDead(_7);                 // scope 0 at $DIR/uniform_array_move_out.rs:+6:5: +6:6
+        drop(_2) -> [return: bb6, unwind: bb12]; // scope 0 at $DIR/uniform_array_move_out.rs:+6:5: +6:6
     }
 
     bb6: {
-        StorageDead(_2);                 // scope 0 at $DIR/uniform_array_move_out.rs:+1:26: +1:27
+        StorageDead(_2);                 // scope 0 at $DIR/uniform_array_move_out.rs:+6:5: +6:6
         FakeRead(ForLet(None), _1);      // scope 0 at $DIR/uniform_array_move_out.rs:+1:9: +1:10
-        PlaceMention(_1);                // scope 1 at $DIR/uniform_array_move_out.rs:+2:20: +2:21
-        StorageLive(_12);                // scope 1 at $DIR/uniform_array_move_out.rs:+2:14: +2:16
-        _12 = move _1[1 of 2];           // scope 1 at $DIR/uniform_array_move_out.rs:+2:14: +2:16
-        _0 = const ();                   // scope 0 at $DIR/uniform_array_move_out.rs:+0:24: +3:2
-        drop(_12) -> [return: bb7, unwind: bb9]; // scope 1 at $DIR/uniform_array_move_out.rs:+3:1: +3:2
+        PlaceMention(_1);                // scope 1 at $DIR/uniform_array_move_out.rs:+7:20: +7:21
+        StorageLive(_12);                // scope 1 at $DIR/uniform_array_move_out.rs:+7:14: +7:16
+        _12 = move _1[1 of 2];           // scope 1 at $DIR/uniform_array_move_out.rs:+7:14: +7:16
+        _0 = const ();                   // scope 0 at $DIR/uniform_array_move_out.rs:+0:24: +8:2
+        drop(_12) -> [return: bb7, unwind: bb9]; // scope 1 at $DIR/uniform_array_move_out.rs:+8:1: +8:2
     }
 
     bb7: {
-        StorageDead(_12);                // scope 1 at $DIR/uniform_array_move_out.rs:+3:1: +3:2
-        drop(_1) -> [return: bb8, unwind: bb12]; // scope 0 at $DIR/uniform_array_move_out.rs:+3:1: +3:2
+        StorageDead(_12);                // scope 1 at $DIR/uniform_array_move_out.rs:+8:1: +8:2
+        drop(_1) -> [return: bb8, unwind: bb12]; // scope 0 at $DIR/uniform_array_move_out.rs:+8:1: +8:2
     }
 
     bb8: {
-        StorageDead(_1);                 // scope 0 at $DIR/uniform_array_move_out.rs:+3:1: +3:2
-        return;                          // scope 0 at $DIR/uniform_array_move_out.rs:+3:2: +3:2
+        StorageDead(_1);                 // scope 0 at $DIR/uniform_array_move_out.rs:+8:1: +8:2
+        return;                          // scope 0 at $DIR/uniform_array_move_out.rs:+8:2: +8:2
     }
 
     bb9 (cleanup): {
-        drop(_1) -> bb12;                // scope 0 at $DIR/uniform_array_move_out.rs:+3:1: +3:2
+        drop(_1) -> bb12;                // scope 0 at $DIR/uniform_array_move_out.rs:+8:1: +8:2
     }
 
     bb10 (cleanup): {
-        drop(_7) -> bb11;                // scope 0 at $DIR/uniform_array_move_out.rs:+1:26: +1:27
+        drop(_7) -> bb11;                // scope 0 at $DIR/uniform_array_move_out.rs:+6:5: +6:6
     }
 
     bb11 (cleanup): {
-        drop(_2) -> bb12;                // scope 0 at $DIR/uniform_array_move_out.rs:+1:26: +1:27
+        drop(_2) -> bb12;                // scope 0 at $DIR/uniform_array_move_out.rs:+6:5: +6:6
     }
 
     bb12 (cleanup): {
-        resume;                          // scope 0 at $DIR/uniform_array_move_out.rs:+0:1: +3:2
+        resume;                          // scope 0 at $DIR/uniform_array_move_out.rs:+0:1: +8:2
     }
 }

tests/mir-opt/building/uniform_array_move_out.rs

@@ -1,14 +1,24 @@
-#![feature(box_syntax)]
+#![feature(stmt_expr_attributes, rustc_attrs)]
 
 // EMIT_MIR uniform_array_move_out.move_out_from_end.built.after.mir
 fn move_out_from_end() {
-    let a = [box 1, box 2];
+    let a = [
+        #[rustc_box]
+        Box::new(1),
+        #[rustc_box]
+        Box::new(2),
+    ];
     let [.., _y] = a;
 }
 
 // EMIT_MIR uniform_array_move_out.move_out_by_subslice.built.after.mir
 fn move_out_by_subslice() {
-    let a = [box 1, box 2];
+    let a = [
+        #[rustc_box]
+        Box::new(1),
+        #[rustc_box]
+        Box::new(2),
+    ];
     let [_y @ ..] = a;
 }
 

tests/mir-opt/const_prop/boxes.main.ConstProp.diff

@@ -4,14 +4,14 @@
   fn main() -> () {
       let mut _0: ();                      // return place in scope 0 at $DIR/boxes.rs:+0:11: +0:11
       let _1: i32;                         // in scope 0 at $DIR/boxes.rs:+1:9: +1:10
-      let mut _2: i32;                     // in scope 0 at $DIR/boxes.rs:+1:13: +1:22
-      let mut _3: std::boxed::Box<i32>;    // in scope 0 at $DIR/boxes.rs:+1:14: +1:22
-      let mut _4: usize;                   // in scope 0 at $DIR/boxes.rs:+1:14: +1:22
-      let mut _5: usize;                   // in scope 0 at $DIR/boxes.rs:+1:14: +1:22
-      let mut _6: *mut u8;                 // in scope 0 at $DIR/boxes.rs:+1:14: +1:22
-      let mut _7: std::boxed::Box<i32>;    // in scope 0 at $DIR/boxes.rs:+1:14: +1:22
-      let mut _8: *const i32;              // in scope 0 at $DIR/boxes.rs:+1:14: +1:22
-      let mut _9: *const i32;              // in scope 0 at $DIR/boxes.rs:+1:14: +1:22
+      let mut _2: i32;                     // in scope 0 at $DIR/boxes.rs:+1:13: +2:18
+      let mut _3: std::boxed::Box<i32>;    // in scope 0 at $DIR/boxes.rs:+1:14: +2:18
+      let mut _4: usize;                   // in scope 0 at $DIR/boxes.rs:+1:14: +2:18
+      let mut _5: usize;                   // in scope 0 at $DIR/boxes.rs:+1:14: +2:18
+      let mut _6: *mut u8;                 // in scope 0 at $DIR/boxes.rs:+1:14: +2:18
+      let mut _7: std::boxed::Box<i32>;    // in scope 0 at $DIR/boxes.rs:+1:14: +2:18
+      let mut _8: *const i32;              // in scope 0 at $DIR/boxes.rs:+1:14: +2:18
+      let mut _9: *const i32;              // in scope 0 at $DIR/boxes.rs:+1:14: +2:18
       scope 1 {
           debug x => _1;                   // in scope 1 at $DIR/boxes.rs:+1:9: +1:10
       }
@@ -20,41 +20,41 @@
   
       bb0: {
           StorageLive(_1);                 // scope 0 at $DIR/boxes.rs:+1:9: +1:10
-          StorageLive(_2);                 // scope 0 at $DIR/boxes.rs:+1:13: +1:22
-          StorageLive(_3);                 // scope 0 at $DIR/boxes.rs:+1:14: +1:22
--         _4 = SizeOf(i32);                // scope 2 at $DIR/boxes.rs:+1:14: +1:22
--         _5 = AlignOf(i32);               // scope 2 at $DIR/boxes.rs:+1:14: +1:22
-+         _4 = const 4_usize;              // scope 2 at $DIR/boxes.rs:+1:14: +1:22
-+         _5 = const 4_usize;              // scope 2 at $DIR/boxes.rs:+1:14: +1:22
-          _6 = alloc::alloc::exchange_malloc(move _4, move _5) -> bb1; // scope 2 at $DIR/boxes.rs:+1:14: +1:22
+          StorageLive(_2);                 // scope 0 at $DIR/boxes.rs:+1:13: +2:18
+          StorageLive(_3);                 // scope 0 at $DIR/boxes.rs:+1:14: +2:18
+-         _4 = SizeOf(i32);                // scope 2 at $DIR/boxes.rs:+1:14: +2:18
+-         _5 = AlignOf(i32);               // scope 2 at $DIR/boxes.rs:+1:14: +2:18
++         _4 = const 4_usize;              // scope 2 at $DIR/boxes.rs:+1:14: +2:18
++         _5 = const 4_usize;              // scope 2 at $DIR/boxes.rs:+1:14: +2:18
+          _6 = alloc::alloc::exchange_malloc(move _4, move _5) -> bb1; // scope 2 at $DIR/boxes.rs:+1:14: +2:18
                                            // mir::Constant
-                                           // + span: $DIR/boxes.rs:13:14: 13:22
+                                           // + span: $DIR/boxes.rs:13:14: 14:18
                                            // + literal: Const { ty: unsafe fn(usize, usize) -> *mut u8 {alloc::alloc::exchange_malloc}, val: Value(<ZST>) }
       }
   
       bb1: {
-          StorageLive(_7);                 // scope 0 at $DIR/boxes.rs:+1:14: +1:22
-          _7 = ShallowInitBox(move _6, i32); // scope 0 at $DIR/boxes.rs:+1:14: +1:22
-          _8 = (((_7.0: std::ptr::Unique<i32>).0: std::ptr::NonNull<i32>).0: *const i32); // scope 0 at $DIR/boxes.rs:+1:19: +1:21
-          (*_8) = const 42_i32;            // scope 0 at $DIR/boxes.rs:+1:19: +1:21
-          _3 = move _7;                    // scope 0 at $DIR/boxes.rs:+1:14: +1:22
-          StorageDead(_7);                 // scope 0 at $DIR/boxes.rs:+1:21: +1:22
-          _9 = (((_3.0: std::ptr::Unique<i32>).0: std::ptr::NonNull<i32>).0: *const i32); // scope 0 at $DIR/boxes.rs:+1:13: +1:22
-          _2 = (*_9);                      // scope 0 at $DIR/boxes.rs:+1:13: +1:22
-          _1 = Add(move _2, const 0_i32);  // scope 0 at $DIR/boxes.rs:+1:13: +1:26
-          StorageDead(_2);                 // scope 0 at $DIR/boxes.rs:+1:25: +1:26
-          drop(_3) -> [return: bb2, unwind: bb3]; // scope 0 at $DIR/boxes.rs:+1:26: +1:27
+          StorageLive(_7);                 // scope 0 at $DIR/boxes.rs:+1:14: +2:18
+          _7 = ShallowInitBox(move _6, i32); // scope 0 at $DIR/boxes.rs:+1:14: +2:18
+          _8 = (((_7.0: std::ptr::Unique<i32>).0: std::ptr::NonNull<i32>).0: *const i32); // scope 0 at $DIR/boxes.rs:+2:14: +2:16
+          (*_8) = const 42_i32;            // scope 0 at $DIR/boxes.rs:+2:14: +2:16
+          _3 = move _7;                    // scope 0 at $DIR/boxes.rs:+1:14: +2:18
+          StorageDead(_7);                 // scope 0 at $DIR/boxes.rs:+2:17: +2:18
+          _9 = (((_3.0: std::ptr::Unique<i32>).0: std::ptr::NonNull<i32>).0: *const i32); // scope 0 at $DIR/boxes.rs:+1:13: +2:18
+          _2 = (*_9);                      // scope 0 at $DIR/boxes.rs:+1:13: +2:18
+          _1 = Add(move _2, const 0_i32);  // scope 0 at $DIR/boxes.rs:+1:13: +3:12
+          StorageDead(_2);                 // scope 0 at $DIR/boxes.rs:+3:11: +3:12
+          drop(_3) -> [return: bb2, unwind: bb3]; // scope 0 at $DIR/boxes.rs:+3:12: +3:13
       }
   
       bb2: {
-          StorageDead(_3);                 // scope 0 at $DIR/boxes.rs:+1:26: +1:27
-          _0 = const ();                   // scope 0 at $DIR/boxes.rs:+0:11: +2:2
-          StorageDead(_1);                 // scope 0 at $DIR/boxes.rs:+2:1: +2:2
-          return;                          // scope 0 at $DIR/boxes.rs:+2:2: +2:2
+          StorageDead(_3);                 // scope 0 at $DIR/boxes.rs:+3:12: +3:13
+          _0 = const ();                   // scope 0 at $DIR/boxes.rs:+0:11: +4:2
+          StorageDead(_1);                 // scope 0 at $DIR/boxes.rs:+4:1: +4:2
+          return;                          // scope 0 at $DIR/boxes.rs:+4:2: +4:2
       }
   
       bb3 (cleanup): {
-          resume;                          // scope 0 at $DIR/boxes.rs:+0:1: +2:2
+          resume;                          // scope 0 at $DIR/boxes.rs:+0:1: +4:2
       }
   }
   

tests/mir-opt/const_prop/boxes.rs

@@ -4,11 +4,13 @@
 // ignore-wasm32
 // ignore-wasm64
 
-#![feature(box_syntax)]
+#![feature(rustc_attrs, stmt_expr_attributes)]
 
-// Note: this test verifies that we, in fact, do not const prop `box`
+// Note: this test verifies that we, in fact, do not const prop `#[rustc_box]`
 
 // EMIT_MIR boxes.main.ConstProp.diff
 fn main() {
-    let x = *(box 42) + 0;
+    let x = *(#[rustc_box]
+    Box::new(42))
+        + 0;
 }

tests/mir-opt/derefer_inline_test.main.Derefer.diff

@@ -3,58 +3,42 @@
   
   fn main() -> () {
       let mut _0: ();                      // return place in scope 0 at $DIR/derefer_inline_test.rs:+0:11: +0:11
-      let _1: std::boxed::Box<std::boxed::Box<u32>>; // in scope 0 at $DIR/derefer_inline_test.rs:+1:5: +1:12
-      let mut _2: usize;                   // in scope 0 at $DIR/derefer_inline_test.rs:+1:5: +1:12
-      let mut _3: usize;                   // in scope 0 at $DIR/derefer_inline_test.rs:+1:5: +1:12
-      let mut _4: *mut u8;                 // in scope 0 at $DIR/derefer_inline_test.rs:+1:5: +1:12
-      let mut _5: std::boxed::Box<std::boxed::Box<u32>>; // in scope 0 at $DIR/derefer_inline_test.rs:+1:5: +1:12
-      scope 1 {
-      }
+      let _1: std::boxed::Box<std::boxed::Box<u32>>; // in scope 0 at $DIR/derefer_inline_test.rs:+1:5: +1:18
+      let mut _2: std::boxed::Box<u32>;    // in scope 0 at $DIR/derefer_inline_test.rs:+1:14: +1:17
   
       bb0: {
-          StorageLive(_1);                 // scope 0 at $DIR/derefer_inline_test.rs:+1:5: +1:12
-          _2 = SizeOf(std::boxed::Box<u32>); // scope 1 at $DIR/derefer_inline_test.rs:+1:5: +1:12
-          _3 = AlignOf(std::boxed::Box<u32>); // scope 1 at $DIR/derefer_inline_test.rs:+1:5: +1:12
-          _4 = alloc::alloc::exchange_malloc(move _2, move _3) -> bb1; // scope 1 at $DIR/derefer_inline_test.rs:+1:5: +1:12
+          StorageLive(_1);                 // scope 0 at $DIR/derefer_inline_test.rs:+1:5: +1:18
+          StorageLive(_2);                 // scope 0 at $DIR/derefer_inline_test.rs:+1:14: +1:17
+          _2 = f() -> bb1;                 // scope 0 at $DIR/derefer_inline_test.rs:+1:14: +1:17
                                            // mir::Constant
-                                           // + span: $DIR/derefer_inline_test.rs:11:5: 11:12
-                                           // + literal: Const { ty: unsafe fn(usize, usize) -> *mut u8 {alloc::alloc::exchange_malloc}, val: Value(<ZST>) }
-      }
-  
-      bb1: {
-          StorageLive(_5);                 // scope 0 at $DIR/derefer_inline_test.rs:+1:5: +1:12
-          _5 = ShallowInitBox(move _4, std::boxed::Box<u32>); // scope 0 at $DIR/derefer_inline_test.rs:+1:5: +1:12
-          (*_5) = f() -> [return: bb2, unwind: bb6]; // scope 0 at $DIR/derefer_inline_test.rs:+1:9: +1:12
-                                           // mir::Constant
-                                           // + span: $DIR/derefer_inline_test.rs:11:9: 11:10
+                                           // + span: $DIR/derefer_inline_test.rs:10:14: 10:15
                                            // + literal: Const { ty: fn() -> Box<u32> {f}, val: Value(<ZST>) }
       }
   
+      bb1: {
+          _1 = Box::<Box<u32>>::new(move _2) -> [return: bb2, unwind: bb4]; // scope 0 at $DIR/derefer_inline_test.rs:+1:5: +1:18
+                                           // mir::Constant
+                                           // + span: $DIR/derefer_inline_test.rs:10:5: 10:13
+                                           // + user_ty: UserType(0)
+                                           // + literal: Const { ty: fn(Box<u32>) -> Box<Box<u32>> {Box::<Box<u32>>::new}, val: Value(<ZST>) }
+      }
+  
       bb2: {
-          _1 = move _5;                    // scope 0 at $DIR/derefer_inline_test.rs:+1:5: +1:12
-          drop(_5) -> [return: bb3, unwind: bb5]; // scope 0 at $DIR/derefer_inline_test.rs:+1:11: +1:12
+          StorageDead(_2);                 // scope 0 at $DIR/derefer_inline_test.rs:+1:17: +1:18
+          drop(_1) -> bb3;                 // scope 0 at $DIR/derefer_inline_test.rs:+1:18: +1:19
       }
   
       bb3: {
-          StorageDead(_5);                 // scope 0 at $DIR/derefer_inline_test.rs:+1:11: +1:12
-          drop(_1) -> bb4;                 // scope 0 at $DIR/derefer_inline_test.rs:+1:12: +1:13
-      }
-  
-      bb4: {
-          StorageDead(_1);                 // scope 0 at $DIR/derefer_inline_test.rs:+1:12: +1:13
+          StorageDead(_1);                 // scope 0 at $DIR/derefer_inline_test.rs:+1:18: +1:19
           _0 = const ();                   // scope 0 at $DIR/derefer_inline_test.rs:+0:11: +2:2
           return;                          // scope 0 at $DIR/derefer_inline_test.rs:+2:2: +2:2
       }
   
+      bb4 (cleanup): {
+          drop(_2) -> bb5;                 // scope 0 at $DIR/derefer_inline_test.rs:+1:17: +1:18
+      }
+  
       bb5 (cleanup): {
-          drop(_1) -> bb7;                 // scope 0 at $DIR/derefer_inline_test.rs:+1:12: +1:13
-      }
-  
-      bb6 (cleanup): {
-          drop(_5) -> bb7;                 // scope 0 at $DIR/derefer_inline_test.rs:+1:11: +1:12
-      }
-  
-      bb7 (cleanup): {
           resume;                          // scope 0 at $DIR/derefer_inline_test.rs:+0:1: +2:2
       }
   }

tests/mir-opt/derefer_inline_test.rs

@@ -2,11 +2,10 @@
 // EMIT_MIR derefer_inline_test.main.Derefer.diff
 // ignore-wasm32 compiled with panic=abort by default
 
-#![feature(box_syntax)]
 #[inline]
 fn f() -> Box<u32> {
-    box 0
+    Box::new(0)
 }
 fn main() {
-    box f();
+    Box::new(f());
 }

tests/mir-opt/inline/inline_into_box_place.main.Inline.diff

@@ -4,81 +4,78 @@
   fn main() -> () {
       let mut _0: ();                      // return place in scope 0 at $DIR/inline_into_box_place.rs:+0:11: +0:11
       let _1: std::boxed::Box<std::vec::Vec<u32>>; // in scope 0 at $DIR/inline_into_box_place.rs:+1:9: +1:11
-      let mut _2: usize;                   // in scope 0 at $DIR/inline_into_box_place.rs:+1:29: +1:43
-      let mut _3: usize;                   // in scope 0 at $DIR/inline_into_box_place.rs:+1:29: +1:43
-      let mut _4: *mut u8;                 // in scope 0 at $DIR/inline_into_box_place.rs:+1:29: +1:43
-      let mut _5: std::boxed::Box<std::vec::Vec<u32>>; // in scope 0 at $DIR/inline_into_box_place.rs:+1:29: +1:43
-      let mut _6: ();                      // in scope 0 at $DIR/inline_into_box_place.rs:+1:42: +1:43
-      let mut _7: *const std::vec::Vec<u32>; // in scope 0 at $DIR/inline_into_box_place.rs:+1:29: +1:43
-+     let mut _8: &mut std::vec::Vec<u32>; // in scope 0 at $DIR/inline_into_box_place.rs:+1:33: +1:43
-+     let mut _9: std::vec::Vec<u32>;      // in scope 0 at $DIR/inline_into_box_place.rs:+1:33: +1:43
+      let mut _2: std::vec::Vec<u32>;      // in scope 0 at $DIR/inline_into_box_place.rs:+1:38: +1:48
       scope 1 {
           debug _x => _1;                  // in scope 1 at $DIR/inline_into_box_place.rs:+1:9: +1:11
       }
-      scope 2 {
-      }
-+     scope 3 (inlined Vec::<u32>::new) {  // at $DIR/inline_into_box_place.rs:8:33: 8:43
-+         let mut _10: alloc::raw_vec::RawVec<u32>; // in scope 3 at $SRC_DIR/alloc/src/vec/mod.rs:LL:COL
++     scope 2 (inlined Vec::<u32>::new) {  // at $DIR/inline_into_box_place.rs:7:38: 7:48
++         let mut _3: alloc::raw_vec::RawVec<u32>; // in scope 2 at $SRC_DIR/alloc/src/vec/mod.rs:LL:COL
++     }
++     scope 3 (inlined Box::<Vec<u32>>::new) { // at $DIR/inline_into_box_place.rs:7:29: 7:49
++         debug x => _2;                   // in scope 3 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
++         let mut _4: usize;               // in scope 3 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
++         let mut _5: usize;               // in scope 3 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
++         let mut _6: *mut u8;             // in scope 3 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
++         let mut _7: *const std::vec::Vec<u32>; // in scope 3 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
++         scope 4 {
++         }
 +     }
   
       bb0: {
           StorageLive(_1);                 // scope 0 at $DIR/inline_into_box_place.rs:+1:9: +1:11
-          _2 = SizeOf(std::vec::Vec<u32>); // scope 2 at $DIR/inline_into_box_place.rs:+1:29: +1:43
-          _3 = AlignOf(std::vec::Vec<u32>); // scope 2 at $DIR/inline_into_box_place.rs:+1:29: +1:43
-          _4 = alloc::alloc::exchange_malloc(move _2, move _3) -> bb1; // scope 2 at $DIR/inline_into_box_place.rs:+1:29: +1:43
+          StorageLive(_2);                 // scope 0 at $DIR/inline_into_box_place.rs:+1:38: +1:48
+-         _2 = Vec::<u32>::new() -> bb1;   // scope 0 at $DIR/inline_into_box_place.rs:+1:38: +1:48
++         StorageLive(_3);                 // scope 2 at $SRC_DIR/alloc/src/vec/mod.rs:LL:COL
++         _3 = const _;                    // scope 2 at $SRC_DIR/alloc/src/vec/mod.rs:LL:COL
                                            // mir::Constant
-                                           // + span: $DIR/inline_into_box_place.rs:8:29: 8:43
-                                           // + literal: Const { ty: unsafe fn(usize, usize) -> *mut u8 {alloc::alloc::exchange_malloc}, val: Value(<ZST>) }
-      }
-  
-      bb1: {
-          StorageLive(_5);                 // scope 0 at $DIR/inline_into_box_place.rs:+1:29: +1:43
-          _5 = ShallowInitBox(move _4, std::vec::Vec<u32>); // scope 0 at $DIR/inline_into_box_place.rs:+1:29: +1:43
-          _7 = (((_5.0: std::ptr::Unique<std::vec::Vec<u32>>).0: std::ptr::NonNull<std::vec::Vec<u32>>).0: *const std::vec::Vec<u32>); // scope 0 at $DIR/inline_into_box_place.rs:+1:33: +1:43
--         (*_7) = Vec::<u32>::new() -> [return: bb2, unwind: bb5]; // scope 0 at $DIR/inline_into_box_place.rs:+1:33: +1:43
-+         StorageLive(_8);                 // scope 0 at $DIR/inline_into_box_place.rs:+1:33: +1:43
-+         _8 = &mut (*_7);                 // scope 0 at $DIR/inline_into_box_place.rs:+1:33: +1:43
-+         StorageLive(_9);                 // scope 0 at $DIR/inline_into_box_place.rs:+1:33: +1:43
-+         StorageLive(_10);                // scope 3 at $SRC_DIR/alloc/src/vec/mod.rs:LL:COL
-+         _10 = const _;                   // scope 3 at $SRC_DIR/alloc/src/vec/mod.rs:LL:COL
-                                           // mir::Constant
--                                          // + span: $DIR/inline_into_box_place.rs:8:33: 8:41
--                                          // + user_ty: UserType(1)
+-                                          // + span: $DIR/inline_into_box_place.rs:7:38: 7:46
+-                                          // + user_ty: UserType(2)
 -                                          // + literal: Const { ty: fn() -> Vec<u32> {Vec::<u32>::new}, val: Value(<ZST>) }
--     }
-- 
--     bb2: {
 +                                          // + span: $SRC_DIR/alloc/src/vec/mod.rs:LL:COL
 +                                          // + user_ty: UserType(0)
 +                                          // + literal: Const { ty: alloc::raw_vec::RawVec<u32>, val: Unevaluated(alloc::raw_vec::RawVec::<T>::NEW, [u32], None) }
-+         _9 = Vec::<u32> { buf: move _10, len: const 0_usize }; // scope 3 at $SRC_DIR/alloc/src/vec/mod.rs:LL:COL
-+         StorageDead(_10);                // scope 3 at $SRC_DIR/alloc/src/vec/mod.rs:LL:COL
-+         (*_8) = move _9;                 // scope 0 at $DIR/inline_into_box_place.rs:+1:33: +1:43
-+         StorageDead(_9);                 // scope 0 at $DIR/inline_into_box_place.rs:+1:33: +1:43
-+         StorageDead(_8);                 // scope 0 at $DIR/inline_into_box_place.rs:+1:33: +1:43
-          _1 = move _5;                    // scope 0 at $DIR/inline_into_box_place.rs:+1:29: +1:43
-          StorageDead(_5);                 // scope 0 at $DIR/inline_into_box_place.rs:+1:42: +1:43
-          _0 = const ();                   // scope 0 at $DIR/inline_into_box_place.rs:+0:11: +2:2
--         drop(_1) -> [return: bb3, unwind: bb4]; // scope 0 at $DIR/inline_into_box_place.rs:+2:1: +2:2
-+         drop(_1) -> [return: bb2, unwind: bb3]; // scope 0 at $DIR/inline_into_box_place.rs:+2:1: +2:2
++         _2 = Vec::<u32> { buf: move _3, len: const 0_usize }; // scope 2 at $SRC_DIR/alloc/src/vec/mod.rs:LL:COL
++         StorageDead(_3);                 // scope 2 at $SRC_DIR/alloc/src/vec/mod.rs:LL:COL
++         _4 = SizeOf(std::vec::Vec<u32>); // scope 4 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
++         _5 = AlignOf(std::vec::Vec<u32>); // scope 4 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
++         _6 = alloc::alloc::exchange_malloc(move _4, move _5) -> [return: bb3, unwind: bb4]; // scope 4 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
++                                          // mir::Constant
++                                          // + span: $SRC_DIR/alloc/src/boxed.rs:LL:COL
++                                          // + literal: Const { ty: unsafe fn(usize, usize) -> *mut u8 {alloc::alloc::exchange_malloc}, val: Value(<ZST>) }
       }
   
--     bb3: {
-+     bb2: {
-          StorageDead(_1);                 // scope 0 at $DIR/inline_into_box_place.rs:+2:1: +2:2
-          return;                          // scope 0 at $DIR/inline_into_box_place.rs:+2:2: +2:2
-      }
-  
--     bb4 (cleanup): {
-+     bb3 (cleanup): {
-          resume;                          // scope 0 at $DIR/inline_into_box_place.rs:+0:1: +2:2
--     }
-- 
--     bb5 (cleanup): {
--         _6 = alloc::alloc::box_free::<Vec<u32>, std::alloc::Global>(move (_5.0: std::ptr::Unique<std::vec::Vec<u32>>), move (_5.1: std::alloc::Global)) -> bb4; // scope 0 at $DIR/inline_into_box_place.rs:+1:42: +1:43
+      bb1: {
+-         _1 = Box::<Vec<u32>>::new(move _2) -> [return: bb2, unwind: bb4]; // scope 0 at $DIR/inline_into_box_place.rs:+1:29: +1:49
 -                                          // mir::Constant
--                                          // + span: $DIR/inline_into_box_place.rs:8:42: 8:43
--                                          // + literal: Const { ty: unsafe fn(Unique<Vec<u32>>, std::alloc::Global) {alloc::alloc::box_free::<Vec<u32>, std::alloc::Global>}, val: Value(<ZST>) }
+-                                          // + span: $DIR/inline_into_box_place.rs:7:29: 7:37
+-                                          // + user_ty: UserType(1)
+-                                          // + literal: Const { ty: fn(Vec<u32>) -> Box<Vec<u32>> {Box::<Vec<u32>>::new}, val: Value(<ZST>) }
++         StorageDead(_1);                 // scope 0 at $DIR/inline_into_box_place.rs:+2:1: +2:2
++         return;                          // scope 0 at $DIR/inline_into_box_place.rs:+2:2: +2:2
+      }
+  
+-     bb2: {
+-         StorageDead(_2);                 // scope 0 at $DIR/inline_into_box_place.rs:+1:48: +1:49
+-         _0 = const ();                   // scope 0 at $DIR/inline_into_box_place.rs:+0:11: +2:2
+-         drop(_1) -> [return: bb3, unwind: bb4]; // scope 0 at $DIR/inline_into_box_place.rs:+2:1: +2:2
++     bb2 (cleanup): {
++         resume;                          // scope 0 at $DIR/inline_into_box_place.rs:+0:1: +2:2
+      }
+  
+      bb3: {
+-         StorageDead(_1);                 // scope 0 at $DIR/inline_into_box_place.rs:+2:1: +2:2
+-         return;                          // scope 0 at $DIR/inline_into_box_place.rs:+2:2: +2:2
++         _1 = ShallowInitBox(move _6, std::vec::Vec<u32>); // scope 3 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
++         _7 = (((_1.0: std::ptr::Unique<std::vec::Vec<u32>>).0: std::ptr::NonNull<std::vec::Vec<u32>>).0: *const std::vec::Vec<u32>); // scope 3 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
++         (*_7) = move _2;                 // scope 3 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
++         StorageDead(_2);                 // scope 0 at $DIR/inline_into_box_place.rs:+1:48: +1:49
++         _0 = const ();                   // scope 0 at $DIR/inline_into_box_place.rs:+0:11: +2:2
++         drop(_1) -> [return: bb1, unwind: bb2]; // scope 0 at $DIR/inline_into_box_place.rs:+2:1: +2:2
+      }
+  
+      bb4 (cleanup): {
+-         resume;                          // scope 0 at $DIR/inline_into_box_place.rs:+0:1: +2:2
++         drop(_2) -> bb2;                 // scope 3 at $SRC_DIR/alloc/src/boxed.rs:LL:COL
       }
   }
   

tests/mir-opt/inline/inline_into_box_place.rs

@@ -2,8 +2,7 @@
 // ignore-wasm32-bare compiled with panic=abort by default
 // compile-flags: -Z mir-opt-level=4
 
-#![feature(box_syntax)]
 // EMIT_MIR inline_into_box_place.main.Inline.diff
 fn main() {
-    let _x: Box<Vec<u32>> = box Vec::new();
+    let _x: Box<Vec<u32>> = Box::new(Vec::new());
 }

tests/mir-opt/issue_62289.rs

@@ -2,11 +2,14 @@
 // initializing it
 // ignore-wasm32-bare compiled with panic=abort by default
 
-#![feature(box_syntax)]
+#![feature(rustc_attrs)]
 
 // EMIT_MIR issue_62289.test.ElaborateDrops.before.mir
 fn test() -> Option<Box<u32>> {
-    Some(box (None?))
+    Some(
+        #[rustc_box]
+        Box::new(None?),
+    )
 }
 
 fn main() {

tests/mir-opt/issue_62289.test.ElaborateDrops.before.mir

@@ -2,121 +2,121 @@
 
 fn test() -> Option<Box<u32>> {
     let mut _0: std::option::Option<std::boxed::Box<u32>>; // return place in scope 0 at $DIR/issue_62289.rs:+0:14: +0:30
-    let mut _1: std::boxed::Box<u32>;    // in scope 0 at $DIR/issue_62289.rs:+1:10: +1:21
-    let mut _2: usize;                   // in scope 0 at $DIR/issue_62289.rs:+1:10: +1:21
-    let mut _3: usize;                   // in scope 0 at $DIR/issue_62289.rs:+1:10: +1:21
-    let mut _4: *mut u8;                 // in scope 0 at $DIR/issue_62289.rs:+1:10: +1:21
-    let mut _5: std::boxed::Box<u32>;    // in scope 0 at $DIR/issue_62289.rs:+1:10: +1:21
-    let mut _6: std::ops::ControlFlow<std::option::Option<std::convert::Infallible>, u32>; // in scope 0 at $DIR/issue_62289.rs:+1:15: +1:20
-    let mut _7: std::option::Option<u32>; // in scope 0 at $DIR/issue_62289.rs:+1:15: +1:19
-    let mut _8: isize;                   // in scope 0 at $DIR/issue_62289.rs:+1:19: +1:20
-    let _9: std::option::Option<std::convert::Infallible>; // in scope 0 at $DIR/issue_62289.rs:+1:19: +1:20
-    let mut _10: !;                      // in scope 0 at $DIR/issue_62289.rs:+1:19: +1:20
-    let mut _11: std::option::Option<std::convert::Infallible>; // in scope 0 at $DIR/issue_62289.rs:+1:19: +1:20
-    let _12: u32;                        // in scope 0 at $DIR/issue_62289.rs:+1:15: +1:20
+    let mut _1: std::boxed::Box<u32>;    // in scope 0 at $DIR/issue_62289.rs:+3:9: +3:24
+    let mut _2: usize;                   // in scope 0 at $DIR/issue_62289.rs:+3:9: +3:24
+    let mut _3: usize;                   // in scope 0 at $DIR/issue_62289.rs:+3:9: +3:24
+    let mut _4: *mut u8;                 // in scope 0 at $DIR/issue_62289.rs:+3:9: +3:24
+    let mut _5: std::boxed::Box<u32>;    // in scope 0 at $DIR/issue_62289.rs:+3:9: +3:24
+    let mut _6: std::ops::ControlFlow<std::option::Option<std::convert::Infallible>, u32>; // in scope 0 at $DIR/issue_62289.rs:+3:18: +3:23
+    let mut _7: std::option::Option<u32>; // in scope 0 at $DIR/issue_62289.rs:+3:18: +3:22
+    let mut _8: isize;                   // in scope 0 at $DIR/issue_62289.rs:+3:22: +3:23
+    let _9: std::option::Option<std::convert::Infallible>; // in scope 0 at $DIR/issue_62289.rs:+3:22: +3:23
+    let mut _10: !;                      // in scope 0 at $DIR/issue_62289.rs:+3:22: +3:23
+    let mut _11: std::option::Option<std::convert::Infallible>; // in scope 0 at $DIR/issue_62289.rs:+3:22: +3:23
+    let _12: u32;                        // in scope 0 at $DIR/issue_62289.rs:+3:18: +3:23
     scope 1 {
     }
     scope 2 {
-        debug residual => _9;            // in scope 2 at $DIR/issue_62289.rs:+1:19: +1:20
+        debug residual => _9;            // in scope 2 at $DIR/issue_62289.rs:+3:22: +3:23
         scope 3 {
         }
     }
     scope 4 {
-        debug val => _12;                // in scope 4 at $DIR/issue_62289.rs:+1:15: +1:20
+        debug val => _12;                // in scope 4 at $DIR/issue_62289.rs:+3:18: +3:23
         scope 5 {
         }
     }
 
     bb0: {
-        StorageLive(_1);                 // scope 0 at $DIR/issue_62289.rs:+1:10: +1:21
-        _2 = SizeOf(u32);                // scope 1 at $DIR/issue_62289.rs:+1:10: +1:21
-        _3 = AlignOf(u32);               // scope 1 at $DIR/issue_62289.rs:+1:10: +1:21
-        _4 = alloc::alloc::exchange_malloc(move _2, move _3) -> bb1; // scope 1 at $DIR/issue_62289.rs:+1:10: +1:21
+        StorageLive(_1);                 // scope 0 at $DIR/issue_62289.rs:+3:9: +3:24
+        _2 = SizeOf(u32);                // scope 1 at $DIR/issue_62289.rs:+3:9: +3:24
+        _3 = AlignOf(u32);               // scope 1 at $DIR/issue_62289.rs:+3:9: +3:24
+        _4 = alloc::alloc::exchange_malloc(move _2, move _3) -> bb1; // scope 1 at $DIR/issue_62289.rs:+3:9: +3:24
                                          // mir::Constant
-                                         // + span: $DIR/issue_62289.rs:9:10: 9:21
+                                         // + span: $DIR/issue_62289.rs:11:9: 11:24
                                          // + literal: Const { ty: unsafe fn(usize, usize) -> *mut u8 {alloc::alloc::exchange_malloc}, val: Value(<ZST>) }
     }
 
     bb1: {
-        StorageLive(_5);                 // scope 0 at $DIR/issue_62289.rs:+1:10: +1:21
-        _5 = ShallowInitBox(move _4, u32); // scope 0 at $DIR/issue_62289.rs:+1:10: +1:21
-        StorageLive(_6);                 // scope 0 at $DIR/issue_62289.rs:+1:15: +1:20
-        StorageLive(_7);                 // scope 0 at $DIR/issue_62289.rs:+1:15: +1:19
-        _7 = Option::<u32>::None;        // scope 0 at $DIR/issue_62289.rs:+1:15: +1:19
-        _6 = <Option<u32> as Try>::branch(move _7) -> [return: bb2, unwind: bb12]; // scope 0 at $DIR/issue_62289.rs:+1:15: +1:20
+        StorageLive(_5);                 // scope 0 at $DIR/issue_62289.rs:+3:9: +3:24
+        _5 = ShallowInitBox(move _4, u32); // scope 0 at $DIR/issue_62289.rs:+3:9: +3:24
+        StorageLive(_6);                 // scope 0 at $DIR/issue_62289.rs:+3:18: +3:23
+        StorageLive(_7);                 // scope 0 at $DIR/issue_62289.rs:+3:18: +3:22
+        _7 = Option::<u32>::None;        // scope 0 at $DIR/issue_62289.rs:+3:18: +3:22
+        _6 = <Option<u32> as Try>::branch(move _7) -> [return: bb2, unwind: bb12]; // scope 0 at $DIR/issue_62289.rs:+3:18: +3:23
                                          // mir::Constant
-                                         // + span: $DIR/issue_62289.rs:9:15: 9:20
+                                         // + span: $DIR/issue_62289.rs:11:18: 11:23
                                          // + literal: Const { ty: fn(Option<u32>) -> ControlFlow<<Option<u32> as Try>::Residual, <Option<u32> as Try>::Output> {<Option<u32> as Try>::branch}, val: Value(<ZST>) }
     }
 
     bb2: {
-        StorageDead(_7);                 // scope 0 at $DIR/issue_62289.rs:+1:19: +1:20
-        _8 = discriminant(_6);           // scope 0 at $DIR/issue_62289.rs:+1:15: +1:20
-        switchInt(move _8) -> [0: bb3, 1: bb5, otherwise: bb4]; // scope 0 at $DIR/issue_62289.rs:+1:15: +1:20
+        StorageDead(_7);                 // scope 0 at $DIR/issue_62289.rs:+3:22: +3:23
+        _8 = discriminant(_6);           // scope 0 at $DIR/issue_62289.rs:+3:18: +3:23
+        switchInt(move _8) -> [0: bb3, 1: bb5, otherwise: bb4]; // scope 0 at $DIR/issue_62289.rs:+3:18: +3:23
     }
 
     bb3: {
-        StorageLive(_12);                // scope 0 at $DIR/issue_62289.rs:+1:15: +1:20
-        _12 = ((_6 as Continue).0: u32); // scope 0 at $DIR/issue_62289.rs:+1:15: +1:20
-        (*_5) = _12;                     // scope 5 at $DIR/issue_62289.rs:+1:15: +1:20
-        StorageDead(_12);                // scope 0 at $DIR/issue_62289.rs:+1:19: +1:20
-        _1 = move _5;                    // scope 0 at $DIR/issue_62289.rs:+1:10: +1:21
-        drop(_5) -> [return: bb7, unwind: bb11]; // scope 0 at $DIR/issue_62289.rs:+1:20: +1:21
+        StorageLive(_12);                // scope 0 at $DIR/issue_62289.rs:+3:18: +3:23
+        _12 = ((_6 as Continue).0: u32); // scope 0 at $DIR/issue_62289.rs:+3:18: +3:23
+        (*_5) = _12;                     // scope 5 at $DIR/issue_62289.rs:+3:18: +3:23
+        StorageDead(_12);                // scope 0 at $DIR/issue_62289.rs:+3:22: +3:23
+        _1 = move _5;                    // scope 0 at $DIR/issue_62289.rs:+3:9: +3:24
+        drop(_5) -> [return: bb7, unwind: bb11]; // scope 0 at $DIR/issue_62289.rs:+3:23: +3:24
     }
 
     bb4: {
-        unreachable;                     // scope 0 at $DIR/issue_62289.rs:+1:15: +1:20
+        unreachable;                     // scope 0 at $DIR/issue_62289.rs:+3:18: +3:23
     }
 
     bb5: {
-        StorageLive(_9);                 // scope 0 at $DIR/issue_62289.rs:+1:19: +1:20
-        _9 = ((_6 as Break).0: std::option::Option<std::convert::Infallible>); // scope 0 at $DIR/issue_62289.rs:+1:19: +1:20
-        StorageLive(_11);                // scope 3 at $DIR/issue_62289.rs:+1:19: +1:20
-        _11 = _9;                        // scope 3 at $DIR/issue_62289.rs:+1:19: +1:20
-        _0 = <Option<Box<u32>> as FromResidual<Option<Infallible>>>::from_residual(move _11) -> [return: bb6, unwind: bb12]; // scope 3 at $DIR/issue_62289.rs:+1:15: +1:20
+        StorageLive(_9);                 // scope 0 at $DIR/issue_62289.rs:+3:22: +3:23
+        _9 = ((_6 as Break).0: std::option::Option<std::convert::Infallible>); // scope 0 at $DIR/issue_62289.rs:+3:22: +3:23
+        StorageLive(_11);                // scope 3 at $DIR/issue_62289.rs:+3:22: +3:23
+        _11 = _9;                        // scope 3 at $DIR/issue_62289.rs:+3:22: +3:23
+        _0 = <Option<Box<u32>> as FromResidual<Option<Infallible>>>::from_residual(move _11) -> [return: bb6, unwind: bb12]; // scope 3 at $DIR/issue_62289.rs:+3:18: +3:23
                                          // mir::Constant
-                                         // + span: $DIR/issue_62289.rs:9:19: 9:20
+                                         // + span: $DIR/issue_62289.rs:11:22: 11:23
                                          // + literal: Const { ty: fn(Option<Infallible>) -> Option<Box<u32>> {<Option<Box<u32>> as FromResidual<Option<Infallible>>>::from_residual}, val: Value(<ZST>) }
     }
 
     bb6: {
-        StorageDead(_11);                // scope 3 at $DIR/issue_62289.rs:+1:19: +1:20
-        StorageDead(_9);                 // scope 0 at $DIR/issue_62289.rs:+1:19: +1:20
-        drop(_5) -> bb9;                 // scope 0 at $DIR/issue_62289.rs:+1:20: +1:21
+        StorageDead(_11);                // scope 3 at $DIR/issue_62289.rs:+3:22: +3:23
+        StorageDead(_9);                 // scope 0 at $DIR/issue_62289.rs:+3:22: +3:23
+        drop(_5) -> bb9;                 // scope 0 at $DIR/issue_62289.rs:+3:23: +3:24
     }
 
     bb7: {
-        StorageDead(_5);                 // scope 0 at $DIR/issue_62289.rs:+1:20: +1:21
-        _0 = Option::<Box<u32>>::Some(move _1); // scope 0 at $DIR/issue_62289.rs:+1:5: +1:22
-        drop(_1) -> bb8;                 // scope 0 at $DIR/issue_62289.rs:+1:21: +1:22
+        StorageDead(_5);                 // scope 0 at $DIR/issue_62289.rs:+3:23: +3:24
+        _0 = Option::<Box<u32>>::Some(move _1); // scope 0 at $DIR/issue_62289.rs:+1:5: +4:6
+        drop(_1) -> bb8;                 // scope 0 at $DIR/issue_62289.rs:+4:5: +4:6
     }
 
     bb8: {
-        StorageDead(_1);                 // scope 0 at $DIR/issue_62289.rs:+1:21: +1:22
-        StorageDead(_6);                 // scope 0 at $DIR/issue_62289.rs:+2:1: +2:2
-        goto -> bb10;                    // scope 0 at $DIR/issue_62289.rs:+2:2: +2:2
+        StorageDead(_1);                 // scope 0 at $DIR/issue_62289.rs:+4:5: +4:6
+        StorageDead(_6);                 // scope 0 at $DIR/issue_62289.rs:+5:1: +5:2
+        goto -> bb10;                    // scope 0 at $DIR/issue_62289.rs:+5:2: +5:2
     }
 
     bb9: {
-        StorageDead(_5);                 // scope 0 at $DIR/issue_62289.rs:+1:20: +1:21
-        StorageDead(_1);                 // scope 0 at $DIR/issue_62289.rs:+1:21: +1:22
-        StorageDead(_6);                 // scope 0 at $DIR/issue_62289.rs:+2:1: +2:2
-        goto -> bb10;                    // scope 0 at $DIR/issue_62289.rs:+2:2: +2:2
+        StorageDead(_5);                 // scope 0 at $DIR/issue_62289.rs:+3:23: +3:24
+        StorageDead(_1);                 // scope 0 at $DIR/issue_62289.rs:+4:5: +4:6
+        StorageDead(_6);                 // scope 0 at $DIR/issue_62289.rs:+5:1: +5:2
+        goto -> bb10;                    // scope 0 at $DIR/issue_62289.rs:+5:2: +5:2
     }
 
     bb10: {
-        return;                          // scope 0 at $DIR/issue_62289.rs:+2:2: +2:2
+        return;                          // scope 0 at $DIR/issue_62289.rs:+5:2: +5:2
     }
 
     bb11 (cleanup): {
-        drop(_1) -> bb13;                // scope 0 at $DIR/issue_62289.rs:+1:21: +1:22
+        drop(_1) -> bb13;                // scope 0 at $DIR/issue_62289.rs:+4:5: +4:6
     }
 
     bb12 (cleanup): {
-        drop(_5) -> bb13;                // scope 0 at $DIR/issue_62289.rs:+1:20: +1:21
+        drop(_5) -> bb13;                // scope 0 at $DIR/issue_62289.rs:+3:23: +3:24
     }
 
     bb13 (cleanup): {
-        resume;                          // scope 0 at $DIR/issue_62289.rs:+0:1: +2:2
+        resume;                          // scope 0 at $DIR/issue_62289.rs:+0:1: +5:2
     }
 }

tests/pretty/ast-stmt-expr-attr.rs

@@ -4,7 +4,6 @@ fn main() {}
 
 #[cfg(FALSE)]
 fn syntax() {
-    let _ = #[attr] box 0;
     let _ = #[attr] [];
     let _ = #[attr] [0];
     let _ = #[attr] [0; 0];

tests/pretty/stmt_expr_attributes.rs

@@ -1,6 +1,5 @@
 // pp-exact
 
-#![feature(box_syntax)]
 #![feature(inline_const)]
 #![feature(inline_const_pat)]
 #![feature(rustc_attrs)]
@@ -140,7 +139,6 @@ fn _10() {
 }
 
 fn _11() {
-    let _ = #[rustc_dummy] box 0;
     let _: [(); 0] = #[rustc_dummy] [];
     let _ = #[rustc_dummy] [0, 0];
     let _ = #[rustc_dummy] [0; 0];

tests/ui-fulldeps/pprust-expr-roundtrip.rs

@@ -73,11 +73,10 @@ fn iter_exprs(depth: usize, f: &mut dyn FnMut(P<Expr>)) {
 
     let mut g = |e| f(expr(e));
 
-    for kind in 0..=19 {
+    for kind in 0..=18 {
         match kind {
-            0 => iter_exprs(depth - 1, &mut |e| g(ExprKind::Box(e))),
-            1 => iter_exprs(depth - 1, &mut |e| g(ExprKind::Call(e, thin_vec![]))),
-            2 => {
+            0 => iter_exprs(depth - 1, &mut |e| g(ExprKind::Call(e, thin_vec![]))),
+            1 => {
                 let seg = PathSegment::from_ident(Ident::from_str("x"));
                 iter_exprs(depth - 1, &mut |e| {
                     g(ExprKind::MethodCall(Box::new(MethodCall {
@@ -90,26 +89,26 @@ fn iter_exprs(depth: usize, f: &mut dyn FnMut(P<Expr>)) {
                     }))
                 )});
             }
-            3..=8 => {
+            2..=7 => {
                 let op = Spanned {
                     span: DUMMY_SP,
                     node: match kind {
-                        3 => BinOpKind::Add,
-                        4 => BinOpKind::Mul,
-                        5 => BinOpKind::Shl,
-                        6 => BinOpKind::And,
-                        7 => BinOpKind::Or,
-                        8 => BinOpKind::Lt,
+                        2 => BinOpKind::Add,
+                        3 => BinOpKind::Mul,
+                        4 => BinOpKind::Shl,
+                        5 => BinOpKind::And,
+                        6 => BinOpKind::Or,
+                        7 => BinOpKind::Lt,
                         _ => unreachable!(),
                     },
                 };
                 iter_exprs(depth - 1, &mut |e| g(ExprKind::Binary(op, e, make_x())));
                 iter_exprs(depth - 1, &mut |e| g(ExprKind::Binary(op, make_x(), e)));
             }
-            9 => {
+            8 => {
                 iter_exprs(depth - 1, &mut |e| g(ExprKind::Unary(UnOp::Deref, e)));
             }
-            10 => {
+            9 => {
                 let block = P(Block {
                     stmts: ThinVec::new(),
                     id: DUMMY_NODE_ID,
@@ -120,7 +119,7 @@ fn iter_exprs(depth: usize, f: &mut dyn FnMut(P<Expr>)) {
                 });
                 iter_exprs(depth - 1, &mut |e| g(ExprKind::If(e, block.clone(), None)));
             }
-            11 => {
+            10 => {
                 let decl = P(FnDecl { inputs: thin_vec![], output: FnRetTy::Default(DUMMY_SP) });
                 iter_exprs(depth - 1, &mut |e| {
                     g(ExprKind::Closure(Box::new(Closure {
@@ -136,14 +135,14 @@ fn iter_exprs(depth: usize, f: &mut dyn FnMut(P<Expr>)) {
                     })))
                 });
             }
-            12 => {
+            11 => {
                 iter_exprs(depth - 1, &mut |e| g(ExprKind::Assign(e, make_x(), DUMMY_SP)));
                 iter_exprs(depth - 1, &mut |e| g(ExprKind::Assign(make_x(), e, DUMMY_SP)));
             }
-            13 => {
+            12 => {
                 iter_exprs(depth - 1, &mut |e| g(ExprKind::Field(e, Ident::from_str("f"))));
             }
-            14 => {
+            13 => {
                 iter_exprs(depth - 1, &mut |e| {
                     g(ExprKind::Range(Some(e), Some(make_x()), RangeLimits::HalfOpen))
                 });
@@ -151,16 +150,16 @@ fn iter_exprs(depth: usize, f: &mut dyn FnMut(P<Expr>)) {
                     g(ExprKind::Range(Some(make_x()), Some(e), RangeLimits::HalfOpen))
                 });
             }
-            15 => {
+            14 => {
                 iter_exprs(depth - 1, &mut |e| {
                     g(ExprKind::AddrOf(BorrowKind::Ref, Mutability::Not, e))
                 });
             }
-            16 => {
+            15 => {
                 g(ExprKind::Ret(None));
                 iter_exprs(depth - 1, &mut |e| g(ExprKind::Ret(Some(e))));
             }
-            17 => {
+            16 => {
                 let path = Path::from_ident(Ident::from_str("S"));
                 g(ExprKind::Struct(P(StructExpr {
                     qself: None,
@@ -169,10 +168,10 @@ fn iter_exprs(depth: usize, f: &mut dyn FnMut(P<Expr>)) {
                     rest: StructRest::Base(make_x()),
                 })));
             }
-            18 => {
+            17 => {
                 iter_exprs(depth - 1, &mut |e| g(ExprKind::Try(e)));
             }
-            19 => {
+            18 => {
                 let pat =
                     P(Pat { id: DUMMY_NODE_ID, kind: PatKind::Wild, span: DUMMY_SP, tokens: None });
                 iter_exprs(depth - 1, &mut |e| g(ExprKind::Let(pat.clone(), e, DUMMY_SP)))

tests/ui/check-static-values-constraints.rs

@@ -1,7 +1,6 @@
 // Verifies all possible restrictions for statics values.
 
 #![allow(warnings)]
-#![feature(box_syntax)]
 
 use std::marker;
 
@@ -19,7 +18,7 @@ enum SafeEnum {
     Variant1,
     Variant2(isize),
     Variant3(WithDtor),
-    Variant4(String)
+    Variant4(String),
 }
 
 // These should be ok
@@ -29,42 +28,45 @@ static STATIC3: SafeEnum = SafeEnum::Variant3(WithDtor);
 
 enum UnsafeEnum {
     Variant5,
-    Variant6(isize)
+    Variant6(isize),
 }
 
 impl Drop for UnsafeEnum {
     fn drop(&mut self) {}
 }
 
-
 static STATIC4: UnsafeEnum = UnsafeEnum::Variant5;
 static STATIC5: UnsafeEnum = UnsafeEnum::Variant6(0);
 
-
 struct SafeStruct {
     field1: SafeEnum,
     field2: SafeEnum,
 }
 
-
 // Struct fields are safe, hence this static should be safe
-static STATIC6: SafeStruct = SafeStruct{field1: SafeEnum::Variant1, field2: SafeEnum::Variant2(0)};
+static STATIC6: SafeStruct =
+    SafeStruct { field1: SafeEnum::Variant1, field2: SafeEnum::Variant2(0) };
 
-static STATIC7: SafeStruct = SafeStruct{field1: SafeEnum::Variant1,
-                                        field2: SafeEnum::Variant3(WithDtor)};
+static STATIC7: SafeStruct =
+    SafeStruct { field1: SafeEnum::Variant1, field2: SafeEnum::Variant3(WithDtor) };
 
 // Test variadic constructor for structs. The base struct should be examined
 // as well as every field present in the constructor.
 // This example shouldn't fail because all the fields are safe.
-static STATIC8: SafeStruct = SafeStruct{field1: SafeEnum::Variant1,
-                                        ..SafeStruct{field1: SafeEnum::Variant1,
-                                                     field2: SafeEnum::Variant1}};
+static STATIC8: SafeStruct = SafeStruct {
+    field1: SafeEnum::Variant1,
+    ..SafeStruct { field1: SafeEnum::Variant1, field2: SafeEnum::Variant1 }
+};
 
 // This example should fail because field1 in the base struct is not safe
-static STATIC9: SafeStruct = SafeStruct{field1: SafeEnum::Variant1,
-                                        ..SafeStruct{field1: SafeEnum::Variant3(WithDtor),
-//~^ ERROR destructor of
-                                                     field2: SafeEnum::Variant1}};
+static STATIC9: SafeStruct = SafeStruct {
+    field1: SafeEnum::Variant1,
+    ..SafeStruct {
+        //~^ ERROR destructor of
+        field1: SafeEnum::Variant3(WithDtor),
+        field2: SafeEnum::Variant1,
+    }
+};
 
 struct UnsafeStruct;
 
@@ -76,38 +78,45 @@ static STATIC10: UnsafeStruct = UnsafeStruct;
 
 struct MyOwned;
 
-static STATIC11: Box<MyOwned> = box MyOwned;
+static STATIC11: Vec<MyOwned> = vec![MyOwned];
 //~^ ERROR allocations are not allowed in statics
+//~^^ ERROR cannot call non-const
 
 static mut STATIC12: UnsafeStruct = UnsafeStruct;
 
-static mut STATIC13: SafeStruct = SafeStruct{field1: SafeEnum::Variant1,
-                                             field2: SafeEnum::Variant3(WithDtor)};
+static mut STATIC13: SafeStruct =
+    SafeStruct { field1: SafeEnum::Variant1, field2: SafeEnum::Variant3(WithDtor) };
 
 static mut STATIC14: SafeStruct = SafeStruct {
     field1: SafeEnum::Variant1,
-    field2: SafeEnum::Variant4("str".to_string())
-//~^ ERROR cannot call non-const fn
+    field2: SafeEnum::Variant4("str".to_string()), //~ ERROR cannot call non-const fn
 };
 
-static STATIC15: &'static [Box<MyOwned>] = &[
-    box MyOwned, //~ ERROR allocations are not allowed in statics
-    box MyOwned, //~ ERROR allocations are not allowed in statics
+static STATIC15: &'static [Vec<MyOwned>] = &[
+    vec![MyOwned], //~ ERROR allocations are not allowed in statics
+    //~^ ERROR cannot call non-const
+    vec![MyOwned], //~ ERROR allocations are not allowed in statics
+                   //~^ ERROR cannot call non-const
 ];
 
-static STATIC16: (&'static Box<MyOwned>, &'static Box<MyOwned>) = (
-    &box MyOwned, //~ ERROR allocations are not allowed in statics
-    &box MyOwned, //~ ERROR allocations are not allowed in statics
+static STATIC16: (&'static Vec<MyOwned>, &'static Vec<MyOwned>) = (
+    &vec![MyOwned], //~ ERROR allocations are not allowed in statics
+    //~^ ERROR cannot call non-const
+    &vec![MyOwned], //~ ERROR allocations are not allowed in statics
+                    //~^ ERROR cannot call non-const
 );
 
 static mut STATIC17: SafeEnum = SafeEnum::Variant1;
 
-static STATIC19: Box<isize> =
-    box 3;
+static STATIC19: Vec<isize> = vec![3];
 //~^ ERROR allocations are not allowed in statics
+//~^^ ERROR cannot call non-const
 
 pub fn main() {
-    let y = { static x: Box<isize> = box 3; x };
-    //~^ ERROR allocations are not allowed in statics
-    //~| ERROR cannot move out of static item
+    let y = {
+        static x: Vec<isize> = vec![3]; //~ ERROR allocations are not allowed in statics
+        //~^ ERROR cannot call non-const
+        x
+        //~^ ERROR cannot move out of static
+    };
 }

tests/ui/check-static-values-constraints.stderr

@@ -1,24 +1,38 @@
 error[E0493]: destructor of `SafeStruct` cannot be evaluated at compile-time
-  --> $DIR/check-static-values-constraints.rs:65:43
+  --> $DIR/check-static-values-constraints.rs:64:7
    |
-LL |                                           ..SafeStruct{field1: SafeEnum::Variant3(WithDtor),
-   |  ___________________________________________^
+LL |       ..SafeStruct {
+   |  _______^
 LL | |
-LL | |                                                      field2: SafeEnum::Variant1}};
-   | |                                                                                ^- value is dropped here
-   | |________________________________________________________________________________|
-   |                                                                                  the destructor for this type cannot be evaluated in statics
+LL | |         field1: SafeEnum::Variant3(WithDtor),
+LL | |         field2: SafeEnum::Variant1,
+LL | |     }
+   | |_____^ the destructor for this type cannot be evaluated in statics
+LL |   };
+   |   - value is dropped here
 
 error[E0010]: allocations are not allowed in statics
-  --> $DIR/check-static-values-constraints.rs:79:33
+  --> $DIR/check-static-values-constraints.rs:81:33
    |
-LL | static STATIC11: Box<MyOwned> = box MyOwned;
-   |                                 ^^^^^^^^^^^ allocation not allowed in statics
+LL | static STATIC11: Vec<MyOwned> = vec![MyOwned];
+   |                                 ^^^^^^^^^^^^^ allocation not allowed in statics
+   |
+   = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0015]: cannot call non-const fn `slice::<impl [MyOwned]>::into_vec::<std::alloc::Global>` in statics
+  --> $DIR/check-static-values-constraints.rs:81:33
+   |
+LL | static STATIC11: Vec<MyOwned> = vec![MyOwned];
+   |                                 ^^^^^^^^^^^^^
+   |
+   = note: calls in statics are limited to constant functions, tuple structs and tuple variants
+   = note: consider wrapping this expression in `Lazy::new(|| ...)` from the `once_cell` crate: https://crates.io/crates/once_cell
+   = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0015]: cannot call non-const fn `<str as ToString>::to_string` in statics
-  --> $DIR/check-static-values-constraints.rs:89:38
+  --> $DIR/check-static-values-constraints.rs:92:38
    |
-LL |     field2: SafeEnum::Variant4("str".to_string())
+LL |     field2: SafeEnum::Variant4("str".to_string()),
    |                                      ^^^^^^^^^^^
    |
    = note: calls in statics are limited to constant functions, tuple structs and tuple variants
@@ -26,53 +40,125 @@ LL |     field2: SafeEnum::Variant4("str".to_string())
    = note: consider wrapping this expression in `Lazy::new(|| ...)` from the `once_cell` crate: https://crates.io/crates/once_cell
 
 error[E0010]: allocations are not allowed in statics
-  --> $DIR/check-static-values-constraints.rs:94:5
+  --> $DIR/check-static-values-constraints.rs:96:5
    |
-LL |     box MyOwned,
-   |     ^^^^^^^^^^^ allocation not allowed in statics
+LL |     vec![MyOwned],
+   |     ^^^^^^^^^^^^^ allocation not allowed in statics
+   |
+   = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0015]: cannot call non-const fn `slice::<impl [MyOwned]>::into_vec::<std::alloc::Global>` in statics
+  --> $DIR/check-static-values-constraints.rs:96:5
+   |
+LL |     vec![MyOwned],
+   |     ^^^^^^^^^^^^^
+   |
+   = note: calls in statics are limited to constant functions, tuple structs and tuple variants
+   = note: consider wrapping this expression in `Lazy::new(|| ...)` from the `once_cell` crate: https://crates.io/crates/once_cell
+   = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0010]: allocations are not allowed in statics
-  --> $DIR/check-static-values-constraints.rs:95:5
+  --> $DIR/check-static-values-constraints.rs:98:5
    |
-LL |     box MyOwned,
-   |     ^^^^^^^^^^^ allocation not allowed in statics
+LL |     vec![MyOwned],
+   |     ^^^^^^^^^^^^^ allocation not allowed in statics
+   |
+   = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0015]: cannot call non-const fn `slice::<impl [MyOwned]>::into_vec::<std::alloc::Global>` in statics
+  --> $DIR/check-static-values-constraints.rs:98:5
+   |
+LL |     vec![MyOwned],
+   |     ^^^^^^^^^^^^^
+   |
+   = note: calls in statics are limited to constant functions, tuple structs and tuple variants
+   = note: consider wrapping this expression in `Lazy::new(|| ...)` from the `once_cell` crate: https://crates.io/crates/once_cell
+   = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0010]: allocations are not allowed in statics
-  --> $DIR/check-static-values-constraints.rs:99:6
+  --> $DIR/check-static-values-constraints.rs:103:6
    |
-LL |     &box MyOwned,
-   |      ^^^^^^^^^^^ allocation not allowed in statics
+LL |     &vec![MyOwned],
+   |      ^^^^^^^^^^^^^ allocation not allowed in statics
+   |
+   = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0015]: cannot call non-const fn `slice::<impl [MyOwned]>::into_vec::<std::alloc::Global>` in statics
+  --> $DIR/check-static-values-constraints.rs:103:6
+   |
+LL |     &vec![MyOwned],
+   |      ^^^^^^^^^^^^^
+   |
+   = note: calls in statics are limited to constant functions, tuple structs and tuple variants
+   = note: consider wrapping this expression in `Lazy::new(|| ...)` from the `once_cell` crate: https://crates.io/crates/once_cell
+   = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0010]: allocations are not allowed in statics
-  --> $DIR/check-static-values-constraints.rs:100:6
+  --> $DIR/check-static-values-constraints.rs:105:6
    |
-LL |     &box MyOwned,
-   |      ^^^^^^^^^^^ allocation not allowed in statics
+LL |     &vec![MyOwned],
+   |      ^^^^^^^^^^^^^ allocation not allowed in statics
+   |
+   = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0015]: cannot call non-const fn `slice::<impl [MyOwned]>::into_vec::<std::alloc::Global>` in statics
+  --> $DIR/check-static-values-constraints.rs:105:6
+   |
+LL |     &vec![MyOwned],
+   |      ^^^^^^^^^^^^^
+   |
+   = note: calls in statics are limited to constant functions, tuple structs and tuple variants
+   = note: consider wrapping this expression in `Lazy::new(|| ...)` from the `once_cell` crate: https://crates.io/crates/once_cell
+   = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0010]: allocations are not allowed in statics
-  --> $DIR/check-static-values-constraints.rs:106:5
+  --> $DIR/check-static-values-constraints.rs:111:31
    |
-LL |     box 3;
-   |     ^^^^^ allocation not allowed in statics
+LL | static STATIC19: Vec<isize> = vec![3];
+   |                               ^^^^^^^ allocation not allowed in statics
+   |
+   = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0015]: cannot call non-const fn `slice::<impl [isize]>::into_vec::<std::alloc::Global>` in statics
+  --> $DIR/check-static-values-constraints.rs:111:31
+   |
+LL | static STATIC19: Vec<isize> = vec![3];
+   |                               ^^^^^^^
+   |
+   = note: calls in statics are limited to constant functions, tuple structs and tuple variants
+   = note: consider wrapping this expression in `Lazy::new(|| ...)` from the `once_cell` crate: https://crates.io/crates/once_cell
+   = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0507]: cannot move out of static item `x`
-  --> $DIR/check-static-values-constraints.rs:110:45
+  --> $DIR/check-static-values-constraints.rs:119:9
    |
-LL |     let y = { static x: Box<isize> = box 3; x };
-   |                                             ^ move occurs because `x` has type `Box<isize>`, which does not implement the `Copy` trait
+LL |         x
+   |         ^ move occurs because `x` has type `Vec<isize>`, which does not implement the `Copy` trait
    |
 help: consider borrowing here
    |
-LL |     let y = { static x: Box<isize> = box 3; &x };
+LL |         &x
    |         +
 
 error[E0010]: allocations are not allowed in statics
-  --> $DIR/check-static-values-constraints.rs:110:38
+  --> $DIR/check-static-values-constraints.rs:117:32
    |
-LL |     let y = { static x: Box<isize> = box 3; x };
-   |                                      ^^^^^ allocation not allowed in statics
+LL |         static x: Vec<isize> = vec![3];
+   |                                ^^^^^^^ allocation not allowed in statics
+   |
+   = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: aborting due to 10 previous errors
+error[E0015]: cannot call non-const fn `slice::<impl [isize]>::into_vec::<std::alloc::Global>` in statics
+  --> $DIR/check-static-values-constraints.rs:117:32
+   |
+LL |         static x: Vec<isize> = vec![3];
+   |                                ^^^^^^^
+   |
+   = note: calls in statics are limited to constant functions, tuple structs and tuple variants
+   = note: consider wrapping this expression in `Lazy::new(|| ...)` from the `once_cell` crate: https://crates.io/crates/once_cell
+   = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 17 previous errors
 
 Some errors have detailed explanations: E0010, E0015, E0493, E0507.
 For more information about an error, try `rustc --explain E0010`.

tests/ui/coercion/coerce-expect-unsized-ascribed.rs

@@ -1,18 +1,19 @@
 // A version of coerce-expect-unsized that uses type ascription.
 // Doesn't work so far, but supposed to work eventually
 
-#![feature(box_syntax, type_ascription)]
+#![feature(type_ascription)]
 
 use std::fmt::Debug;
 
 pub fn main() {
-    let _ = type_ascribe!(box { [1, 2, 3] }, Box<[i32]>); //~ ERROR mismatched types
-    let _ = type_ascribe!(box if true { [1, 2, 3] } else { [1, 3, 4] }, Box<[i32]>); //~ ERROR mismatched types
-    let _ = type_ascribe!(box match true { true => [1, 2, 3], false => [1, 3, 4] }, Box<[i32]>);
+    let _ = type_ascribe!(Box::new({ [1, 2, 3] }), Box<[i32]>); //~ ERROR mismatched types
+    let _ = type_ascribe!(Box::new( if true { [1, 2, 3] } else { [1, 3, 4] }), Box<[i32]>); //~ ERROR mismatched types
+    let _ = type_ascribe!(
+        Box::new( match true { true => [1, 2, 3], false => [1, 3, 4] }), Box<[i32]>);
     //~^ ERROR mismatched types
-    let _ = type_ascribe!(box { |x| (x as u8) }, Box<dyn Fn(i32) -> _>); //~ ERROR mismatched types
-    let _ = type_ascribe!(box if true { false } else { true }, Box<dyn Debug>); //~ ERROR mismatched types
-    let _ = type_ascribe!(box match true { true => 'a', false => 'b' }, Box<dyn Debug>); //~ ERROR mismatched types
+    let _ = type_ascribe!(Box::new( { |x| (x as u8) }), Box<dyn Fn(i32) -> _>); //~ ERROR mismatched types
+    let _ = type_ascribe!(Box::new( if true { false } else { true }), Box<dyn Debug>); //~ ERROR mismatched types
+    let _ = type_ascribe!(Box::new( match true { true => 'a', false => 'b' }), Box<dyn Debug>); //~ ERROR mismatched types
 
     let _ = type_ascribe!(&{ [1, 2, 3] }, &[i32]); //~ ERROR mismatched types
     let _ = type_ascribe!(&if true { [1, 2, 3] } else { [1, 3, 4] }, &[i32]); //~ ERROR mismatched types
@@ -27,6 +28,6 @@ pub fn main() {
 
     let _ = type_ascribe!(vec![
         Box::new(|x| (x as u8)),
-        box |x| (x as i16 as u8),
+        Box::new(|x| (x as i16 as u8)),
     ], Vec<Box<dyn Fn(i32) -> _>>);
 }

tests/ui/coercion/coerce-expect-unsized-ascribed.stderr

@@ -1,8 +1,8 @@
 error[E0308]: mismatched types
   --> $DIR/coerce-expect-unsized-ascribed.rs:9:27
    |
-LL |     let _ = type_ascribe!(box { [1, 2, 3] }, Box<[i32]>);
-   |                           ^^^^^^^^^^^^^^^^^ expected `Box<[i32]>`, found `Box<[i32; 3]>`
+LL |     let _ = type_ascribe!(Box::new({ [1, 2, 3] }), Box<[i32]>);
+   |                           ^^^^^^^^^^^^^^^^^^^^^^^ expected `Box<[i32]>`, found `Box<[i32; 3]>`
    |
    = note: expected struct `Box<[i32]>`
               found struct `Box<[i32; 3]>`
@@ -10,50 +10,50 @@ LL |     let _ = type_ascribe!(box { [1, 2, 3] }, Box<[i32]>);
 error[E0308]: mismatched types
   --> $DIR/coerce-expect-unsized-ascribed.rs:10:27
    |
-LL |     let _ = type_ascribe!(box if true { [1, 2, 3] } else { [1, 3, 4] }, Box<[i32]>);
-   |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `Box<[i32]>`, found `Box<[i32; 3]>`
+LL |     let _ = type_ascribe!(Box::new( if true { [1, 2, 3] } else { [1, 3, 4] }), Box<[i32]>);
+   |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `Box<[i32]>`, found `Box<[i32; 3]>`
    |
    = note: expected struct `Box<[i32]>`
               found struct `Box<[i32; 3]>`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-expect-unsized-ascribed.rs:11:27
+  --> $DIR/coerce-expect-unsized-ascribed.rs:12:9
    |
-LL |     let _ = type_ascribe!(box match true { true => [1, 2, 3], false => [1, 3, 4] }, Box<[i32]>);
-   |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `Box<[i32]>`, found `Box<[i32; 3]>`
+LL |         Box::new( match true { true => [1, 2, 3], false => [1, 3, 4] }), Box<[i32]>);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `Box<[i32]>`, found `Box<[i32; 3]>`
    |
    = note: expected struct `Box<[i32]>`
               found struct `Box<[i32; 3]>`
 
-error[E0308]: mismatched types
-  --> $DIR/coerce-expect-unsized-ascribed.rs:13:27
-   |
-LL |     let _ = type_ascribe!(box { |x| (x as u8) }, Box<dyn Fn(i32) -> _>);
-   |                           ^^^^^^^^^^^^^^^^^^^^^ expected `Box<dyn Fn(i32) -> u8>`, found `Box<[closure@coerce-expect-unsized-ascribed.rs:13:33]>`
-   |
-   = note: expected struct `Box<dyn Fn(i32) -> u8>`
-              found struct `Box<[closure@$DIR/coerce-expect-unsized-ascribed.rs:13:33: 13:36]>`
-
 error[E0308]: mismatched types
   --> $DIR/coerce-expect-unsized-ascribed.rs:14:27
    |
-LL |     let _ = type_ascribe!(box if true { false } else { true }, Box<dyn Debug>);
-   |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `Box<dyn Debug>`, found `Box<bool>`
+LL |     let _ = type_ascribe!(Box::new( { |x| (x as u8) }), Box<dyn Fn(i32) -> _>);
+   |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `Box<dyn Fn(i32) -> u8>`, found `Box<[closure@coerce-expect-unsized-ascribed.rs:14:39]>`
+   |
+   = note: expected struct `Box<dyn Fn(i32) -> u8>`
+              found struct `Box<[closure@$DIR/coerce-expect-unsized-ascribed.rs:14:39: 14:42]>`
+
+error[E0308]: mismatched types
+  --> $DIR/coerce-expect-unsized-ascribed.rs:15:27
+   |
+LL |     let _ = type_ascribe!(Box::new( if true { false } else { true }), Box<dyn Debug>);
+   |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `Box<dyn Debug>`, found `Box<bool>`
    |
    = note: expected struct `Box<dyn Debug>`
               found struct `Box<bool>`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-expect-unsized-ascribed.rs:15:27
+  --> $DIR/coerce-expect-unsized-ascribed.rs:16:27
    |
-LL |     let _ = type_ascribe!(box match true { true => 'a', false => 'b' }, Box<dyn Debug>);
-   |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `Box<dyn Debug>`, found `Box<char>`
+LL |     let _ = type_ascribe!(Box::new( match true { true => 'a', false => 'b' }), Box<dyn Debug>);
+   |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `Box<dyn Debug>`, found `Box<char>`
    |
    = note: expected struct `Box<dyn Debug>`
               found struct `Box<char>`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-expect-unsized-ascribed.rs:17:27
+  --> $DIR/coerce-expect-unsized-ascribed.rs:18:27
    |
 LL |     let _ = type_ascribe!(&{ [1, 2, 3] }, &[i32]);
    |                           ^^^^^^^^^^^^^^ expected `&[i32]`, found `&[i32; 3]`
@@ -62,7 +62,7 @@ LL |     let _ = type_ascribe!(&{ [1, 2, 3] }, &[i32]);
               found reference `&[i32; 3]`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-expect-unsized-ascribed.rs:18:27
+  --> $DIR/coerce-expect-unsized-ascribed.rs:19:27
    |
 LL |     let _ = type_ascribe!(&if true { [1, 2, 3] } else { [1, 3, 4] }, &[i32]);
    |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `&[i32]`, found `&[i32; 3]`
@@ -71,7 +71,7 @@ LL |     let _ = type_ascribe!(&if true { [1, 2, 3] } else { [1, 3, 4] }, &[i32]
               found reference `&[i32; 3]`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-expect-unsized-ascribed.rs:19:27
+  --> $DIR/coerce-expect-unsized-ascribed.rs:20:27
    |
 LL |     let _ = type_ascribe!(&match true { true => [1, 2, 3], false => [1, 3, 4] }, &[i32]);
    |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `&[i32]`, found `&[i32; 3]`
@@ -80,16 +80,16 @@ LL |     let _ = type_ascribe!(&match true { true => [1, 2, 3], false => [1, 3,
               found reference `&[i32; 3]`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-expect-unsized-ascribed.rs:21:27
+  --> $DIR/coerce-expect-unsized-ascribed.rs:22:27
    |
 LL |     let _ = type_ascribe!(&{ |x| (x as u8) }, &dyn Fn(i32) -> _);
-   |                           ^^^^^^^^^^^^^^^^^^ expected `&dyn Fn(i32) -> u8`, found `&[closure@coerce-expect-unsized-ascribed.rs:21:30]`
+   |                           ^^^^^^^^^^^^^^^^^^ expected `&dyn Fn(i32) -> u8`, found `&[closure@coerce-expect-unsized-ascribed.rs:22:30]`
    |
    = note: expected reference `&dyn Fn(i32) -> u8`
-              found reference `&[closure@$DIR/coerce-expect-unsized-ascribed.rs:21:30: 21:33]`
+              found reference `&[closure@$DIR/coerce-expect-unsized-ascribed.rs:22:30: 22:33]`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-expect-unsized-ascribed.rs:22:27
+  --> $DIR/coerce-expect-unsized-ascribed.rs:23:27
    |
 LL |     let _ = type_ascribe!(&if true { false } else { true }, &dyn Debug);
    |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `&dyn Debug`, found `&bool`
@@ -98,7 +98,7 @@ LL |     let _ = type_ascribe!(&if true { false } else { true }, &dyn Debug);
               found reference `&bool`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-expect-unsized-ascribed.rs:23:27
+  --> $DIR/coerce-expect-unsized-ascribed.rs:24:27
    |
 LL |     let _ = type_ascribe!(&match true { true => 'a', false => 'b' }, &dyn Debug);
    |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `&dyn Debug`, found `&char`
@@ -107,7 +107,7 @@ LL |     let _ = type_ascribe!(&match true { true => 'a', false => 'b' }, &dyn D
               found reference `&char`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-expect-unsized-ascribed.rs:25:27
+  --> $DIR/coerce-expect-unsized-ascribed.rs:26:27
    |
 LL |     let _ = type_ascribe!(Box::new([1, 2, 3]), Box<[i32]>);
    |                           ^^^^^^^^^^^^^^^^^^^ expected `Box<[i32]>`, found `Box<[i32; 3]>`
@@ -116,13 +116,13 @@ LL |     let _ = type_ascribe!(Box::new([1, 2, 3]), Box<[i32]>);
               found struct `Box<[i32; 3]>`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-expect-unsized-ascribed.rs:26:27
+  --> $DIR/coerce-expect-unsized-ascribed.rs:27:27
    |
 LL |     let _ = type_ascribe!(Box::new(|x| (x as u8)), Box<dyn Fn(i32) -> _>);
-   |                           ^^^^^^^^^^^^^^^^^^^^^^^ expected `Box<dyn Fn(i32) -> u8>`, found `Box<[closure@coerce-expect-unsized-ascribed.rs:26:36]>`
+   |                           ^^^^^^^^^^^^^^^^^^^^^^^ expected `Box<dyn Fn(i32) -> u8>`, found `Box<[closure@coerce-expect-unsized-ascribed.rs:27:36]>`
    |
    = note: expected struct `Box<dyn Fn(i32) -> u8>`
-              found struct `Box<[closure@$DIR/coerce-expect-unsized-ascribed.rs:26:36: 26:39]>`
+              found struct `Box<[closure@$DIR/coerce-expect-unsized-ascribed.rs:27:36: 27:39]>`
 
 error: aborting due to 14 previous errors
 

tests/ui/consts/miri_unleashed/box.rs

@@ -1,12 +1,11 @@
 // compile-flags: -Zunleash-the-miri-inside-of-you
-#![feature(box_syntax)]
 
 use std::mem::ManuallyDrop;
 
 fn main() {}
 
 static TEST_BAD: &mut i32 = {
-    &mut *(box 0)
+    &mut *(Box::new(0))
     //~^ ERROR could not evaluate static initializer
-    //~| NOTE calling non-const function `alloc::alloc::exchange_malloc`
+    //~| NOTE calling non-const function `Box::<i32>::new`
 };

tests/ui/consts/miri_unleashed/box.stderr

@@ -1,31 +1,26 @@
 error[E0080]: could not evaluate static initializer
-  --> $DIR/box.rs:9:11
+  --> $DIR/box.rs:8:11
    |
-LL |     &mut *(box 0)
-   |           ^^^^^^^ calling non-const function `alloc::alloc::exchange_malloc`
+LL |     &mut *(Box::new(0))
+   |           ^^^^^^^^^^^^^ calling non-const function `Box::<i32>::new`
 
 warning: skipping const checks
    |
 help: skipping check that does not even have a feature gate
-  --> $DIR/box.rs:9:11
+  --> $DIR/box.rs:8:11
    |
-LL |     &mut *(box 0)
-   |           ^^^^^^^
-help: skipping check for `const_mut_refs` feature
-  --> $DIR/box.rs:9:16
-   |
-LL |     &mut *(box 0)
-   |                ^
-help: skipping check for `const_mut_refs` feature
-  --> $DIR/box.rs:9:5
-   |
-LL |     &mut *(box 0)
+LL |     &mut *(Box::new(0))
    |           ^^^^^^^^^^^^^
+help: skipping check for `const_mut_refs` feature
+  --> $DIR/box.rs:8:5
+   |
+LL |     &mut *(Box::new(0))
+   |     ^^^^^^^^^^^^^^^^^^^
 help: skipping check that does not even have a feature gate
-  --> $DIR/box.rs:9:5
+  --> $DIR/box.rs:8:5
    |
-LL |     &mut *(box 0)
-   |     ^^^^^^^^^^^^^
+LL |     &mut *(Box::new(0))
+   |     ^^^^^^^^^^^^^^^^^^^
 
 error: aborting due to previous error; 1 warning emitted
 

tests/ui/error-codes/E0010-teach.rs

@@ -1,8 +1,7 @@
 // compile-flags: -Z teach
 
-#![feature(box_syntax)]
 #![allow(warnings)]
 
-const CON : Box<i32> = box 0; //~ ERROR E0010
-
+const CON: Vec<i32> = vec![1, 2, 3]; //~ ERROR E0010
+//~| ERROR cannot call non-const fn
 fn main() {}

tests/ui/error-codes/E0010-teach.stderr

@@ -1,11 +1,22 @@
 error[E0010]: allocations are not allowed in constants
-  --> $DIR/E0010-teach.rs:6:24
+  --> $DIR/E0010-teach.rs:5:23
    |
-LL | const CON : Box<i32> = box 0;
-   |                        ^^^^^ allocation not allowed in constants
+LL | const CON: Vec<i32> = vec![1, 2, 3];
+   |                       ^^^^^^^^^^^^^ allocation not allowed in constants
    |
    = note: The value of statics and constants must be known at compile time, and they live for the entire lifetime of a program. Creating a boxed value allocates memory on the heap at runtime, and therefore cannot be done at compile time.
+   = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: aborting due to previous error
+error[E0015]: cannot call non-const fn `slice::<impl [i32]>::into_vec::<std::alloc::Global>` in constants
+  --> $DIR/E0010-teach.rs:5:23
+   |
+LL | const CON: Vec<i32> = vec![1, 2, 3];
+   |                       ^^^^^^^^^^^^^
+   |
+   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
+   = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-For more information about this error, try `rustc --explain E0010`.
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0010, E0015.
+For more information about an error, try `rustc --explain E0010`.

tests/ui/error-codes/E0010.rs

@@ -1,6 +1,5 @@
-#![feature(box_syntax)]
 #![allow(warnings)]
 
-const CON : Box<i32> = box 0; //~ ERROR E0010
-
+const CON: Vec<i32> = vec![1, 2, 3]; //~ ERROR E0010
+//~| ERROR cannot call non-const fn
 fn main() {}

tests/ui/error-codes/E0010.stderr

@@ -1,9 +1,21 @@
 error[E0010]: allocations are not allowed in constants
-  --> $DIR/E0010.rs:4:24
+  --> $DIR/E0010.rs:3:23
    |
-LL | const CON : Box<i32> = box 0;
-   |                        ^^^^^ allocation not allowed in constants
+LL | const CON: Vec<i32> = vec![1, 2, 3];
+   |                       ^^^^^^^^^^^^^ allocation not allowed in constants
+   |
+   = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: aborting due to previous error
+error[E0015]: cannot call non-const fn `slice::<impl [i32]>::into_vec::<std::alloc::Global>` in constants
+  --> $DIR/E0010.rs:3:23
+   |
+LL | const CON: Vec<i32> = vec![1, 2, 3];
+   |                       ^^^^^^^^^^^^^
+   |
+   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
+   = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-For more information about this error, try `rustc --explain E0010`.
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0010, E0015.
+For more information about an error, try `rustc --explain E0010`.

tests/ui/generator/issue-105084.drop_tracking_mir.stderr

@@ -1,5 +1,5 @@
 error[E0382]: borrow of moved value: `g`
-  --> $DIR/issue-105084.rs:44:14
+  --> $DIR/issue-105084.rs:45:14
    |
 LL |     let mut g = || {
    |         ----- move occurs because `g` has type `[generator@$DIR/issue-105084.rs:22:17: 22:19]`, which does not implement the `Copy` trait
@@ -23,7 +23,7 @@ LL |     let mut h = copy(g.clone());
    |                       ++++++++
 
 error[E0277]: the trait bound `Box<(i32, ())>: Copy` is not satisfied in `[generator@$DIR/issue-105084.rs:22:17: 22:19]`
-  --> $DIR/issue-105084.rs:38:17
+  --> $DIR/issue-105084.rs:39:17
    |
 LL |     let mut g = || {
    |                 -- within this `[generator@$DIR/issue-105084.rs:22:17: 22:19]`
@@ -32,12 +32,12 @@ LL |     let mut h = copy(g);
    |                 ^^^^ within `[generator@$DIR/issue-105084.rs:22:17: 22:19]`, the trait `Copy` is not implemented for `Box<(i32, ())>`
    |
 note: generator does not implement `Copy` as this value is used across a yield
-  --> $DIR/issue-105084.rs:28:25
+  --> $DIR/issue-105084.rs:29:22
    |
-LL |         let t = box (5, yield);
-   |                 --------^^^^^-
+LL |         Box::new((5, yield));
+   |         -------------^^^^^--
    |         |            |
-   |                 |       yield occurs here, with `box (5, yield)` maybe used later
+   |         |            yield occurs here, with `Box::new((5, yield))` maybe used later
    |         has type `Box<(i32, ())>` which does not implement `Copy`
 note: required by a bound in `copy`
   --> $DIR/issue-105084.rs:17:12

tests/ui/generator/issue-105084.rs

@@ -9,7 +9,7 @@
 #![feature(generators)]
 #![feature(generator_clone)]
 #![feature(generator_trait)]
-#![feature(box_syntax)]
+#![feature(rustc_attrs, stmt_expr_attributes)]
 
 use std::ops::Generator;
 use std::pin::Pin;
@@ -25,7 +25,8 @@ fn main() {
         // - create a Box that is ignored for trait computations;
         // - compute fields (and yields);
         // - assign to `t`.
-        let t = box (5, yield);
+        let t = #[rustc_box]
+        Box::new((5, yield));
         drop(t);
     };
 

tests/ui/generator/yield-in-box.rs

@@ -1,24 +0,0 @@
-// run-pass
-// Test that box-statements with yields in them work.
-
-#![feature(generators, box_syntax, generator_trait)]
-use std::pin::Pin;
-use std::ops::Generator;
-use std::ops::GeneratorState;
-
-fn main() {
-    let x = 0i32;
-    || { //~ WARN unused generator that must be used
-        let y = 2u32;
-        {
-            let _t = box (&x, yield 0, &y);
-        }
-        match box (&x, yield 0, &y) {
-            _t => {}
-        }
-    };
-
-    let mut g = |_| box yield;
-    assert_eq!(Pin::new(&mut g).resume(1), GeneratorState::Yielded(()));
-    assert_eq!(Pin::new(&mut g).resume(2), GeneratorState::Complete(box 2));
-}

tests/ui/generator/yield-in-box.stderr

@@ -1,17 +0,0 @@
-warning: unused generator that must be used
-  --> $DIR/yield-in-box.rs:11:5
-   |
-LL | /     || {
-LL | |         let y = 2u32;
-LL | |         {
-LL | |             let _t = box (&x, yield 0, &y);
-...  |
-LL | |         }
-LL | |     };
-   | |_____^
-   |
-   = note: generators are lazy and do nothing unless resumed
-   = note: `#[warn(unused_must_use)]` on by default
-
-warning: 1 warning emitted
-

tests/ui/lang-items/no_owned_box_lang_item.rs

@@ -1,16 +0,0 @@
-// Test that we don't ICE when we are missing the owned_box lang item.
-
-// error-pattern: requires `owned_box` lang_item
-
-#![feature(lang_items, box_syntax)]
-#![no_std]
-
-use core::panic::PanicInfo;
-
-fn main() {
-    let x = box 1i32;
-}
-
-#[lang = "eh_personality"] extern "C" fn eh_personality() {}
-#[lang = "eh_catch_typeinfo"] static EH_CATCH_TYPEINFO: u8 = 0;
-#[lang = "panic_impl"] fn panic_impl(panic: &PanicInfo) -> ! { loop {} }

tests/ui/lang-items/no_owned_box_lang_item.stderr

@@ -1,4 +0,0 @@
-error: requires `owned_box` lang_item
-
-error: aborting due to previous error
-

tests/ui/macros/rfc-2011-nicer-assert-messages/all-expr-kinds.rs

@@ -5,7 +5,7 @@
 // needs-unwind Asserting on contents of error message
 
 #![allow(path_statements, unused_allocation)]
-#![feature(box_syntax, core_intrinsics, generic_assert, generic_assert_internals)]
+#![feature(core_intrinsics, generic_assert, generic_assert_internals)]
 
 macro_rules! test {
   (
@@ -127,9 +127,6 @@ fn main() {
     // block
     [ { elem } == 3 ] => "Assertion failed: { elem } == 3"
 
-    // box
-    [ box elem == box 3 ] => "Assertion failed: box elem == box 3"
-
     // break
     [ loop { break elem; } ==  3 ] => "Assertion failed: loop { break elem; } == 3"
 

tests/ui/macros/stringify.rs

@@ -4,7 +4,6 @@
 
 #![feature(async_closure)]
 #![feature(box_patterns)]
-#![feature(box_syntax)]
 #![feature(const_trait_impl)]
 #![feature(decl_macro)]
 #![feature(generators)]
@@ -91,9 +90,6 @@ fn test_block() {
 
 #[test]
 fn test_expr() {
-    // ExprKind::Box
-    assert_eq!(stringify_expr!(box expr), "box expr");
-
     // ExprKind::Array
     assert_eq!(stringify_expr!([]), "[]");
     assert_eq!(stringify_expr!([true]), "[true]");

tests/ui/mir/mir_boxing.rs

@@ -1,10 +0,0 @@
-// run-pass
-#![feature(box_syntax)]
-
-fn test() -> Box<i32> {
-    box 42
-}
-
-fn main() {
-    assert_eq!(*test(), 42);
-}

tests/ui/parser/attr-stmt-expr-attr-bad.rs

@@ -1,7 +1,5 @@
 fn main() {}
 
-#[cfg(FALSE)] fn e() { let _ = box #![attr] 0; }
-//~^ ERROR an inner attribute is not permitted in this context
 #[cfg(FALSE)] fn e() { let _ = [#[attr]]; }
 //~^ ERROR expected expression, found `]`
 #[cfg(FALSE)] fn e() { let _ = foo#[attr](); }

tests/ui/parser/attr-stmt-expr-attr-bad.stderr

@@ -1,26 +1,17 @@
-error: an inner attribute is not permitted in this context
-  --> $DIR/attr-stmt-expr-attr-bad.rs:3:36
-   |
-LL | #[cfg(FALSE)] fn e() { let _ = box #![attr] 0; }
-   |                                    ^^^^^^^^
-   |
-   = note: inner attributes, like `#![no_std]`, annotate the item enclosing them, and are usually found at the beginning of source files
-   = note: outer attributes, like `#[test]`, annotate the item following them
-
 error: expected expression, found `]`
-  --> $DIR/attr-stmt-expr-attr-bad.rs:5:40
+  --> $DIR/attr-stmt-expr-attr-bad.rs:3:40
    |
 LL | #[cfg(FALSE)] fn e() { let _ = [#[attr]]; }
    |                                        ^ expected expression
 
 error: expected one of `!`, `.`, `::`, `;`, `?`, `else`, `{`, or an operator, found `#`
-  --> $DIR/attr-stmt-expr-attr-bad.rs:7:35
+  --> $DIR/attr-stmt-expr-attr-bad.rs:5:35
    |
 LL | #[cfg(FALSE)] fn e() { let _ = foo#[attr](); }
    |                                   ^ expected one of 8 possible tokens
 
 error: an inner attribute is not permitted in this context
-  --> $DIR/attr-stmt-expr-attr-bad.rs:9:36
+  --> $DIR/attr-stmt-expr-attr-bad.rs:7:36
    |
 LL | #[cfg(FALSE)] fn e() { let _ = foo(#![attr]); }
    |                                    ^^^^^^^^
@@ -29,13 +20,13 @@ LL | #[cfg(FALSE)] fn e() { let _ = foo(#![attr]); }
    = note: outer attributes, like `#[test]`, annotate the item following them
 
 error: expected expression, found `)`
-  --> $DIR/attr-stmt-expr-attr-bad.rs:9:44
+  --> $DIR/attr-stmt-expr-attr-bad.rs:7:44
    |
 LL | #[cfg(FALSE)] fn e() { let _ = foo(#![attr]); }
    |                                            ^ expected expression
 
 error: an inner attribute is not permitted in this context
-  --> $DIR/attr-stmt-expr-attr-bad.rs:12:38
+  --> $DIR/attr-stmt-expr-attr-bad.rs:10:38
    |
 LL | #[cfg(FALSE)] fn e() { let _ = x.foo(#![attr]); }
    |                                      ^^^^^^^^
@@ -44,13 +35,13 @@ LL | #[cfg(FALSE)] fn e() { let _ = x.foo(#![attr]); }
    = note: outer attributes, like `#[test]`, annotate the item following them
 
 error: expected expression, found `)`
-  --> $DIR/attr-stmt-expr-attr-bad.rs:12:46
+  --> $DIR/attr-stmt-expr-attr-bad.rs:10:46
    |
 LL | #[cfg(FALSE)] fn e() { let _ = x.foo(#![attr]); }
    |                                              ^ expected expression
 
 error: an inner attribute is not permitted in this context
-  --> $DIR/attr-stmt-expr-attr-bad.rs:15:36
+  --> $DIR/attr-stmt-expr-attr-bad.rs:13:36
    |
 LL | #[cfg(FALSE)] fn e() { let _ = 0 + #![attr] 0; }
    |                                    ^^^^^^^^
@@ -59,7 +50,7 @@ LL | #[cfg(FALSE)] fn e() { let _ = 0 + #![attr] 0; }
    = note: outer attributes, like `#[test]`, annotate the item following them
 
 error: an inner attribute is not permitted in this context
-  --> $DIR/attr-stmt-expr-attr-bad.rs:17:33
+  --> $DIR/attr-stmt-expr-attr-bad.rs:15:33
    |
 LL | #[cfg(FALSE)] fn e() { let _ = !#![attr] 0; }
    |                                 ^^^^^^^^
@@ -68,7 +59,7 @@ LL | #[cfg(FALSE)] fn e() { let _ = !#![attr] 0; }
    = note: outer attributes, like `#[test]`, annotate the item following them
 
 error: an inner attribute is not permitted in this context
-  --> $DIR/attr-stmt-expr-attr-bad.rs:19:33
+  --> $DIR/attr-stmt-expr-attr-bad.rs:17:33
    |
 LL | #[cfg(FALSE)] fn e() { let _ = -#![attr] 0; }
    |                                 ^^^^^^^^
@@ -77,13 +68,13 @@ LL | #[cfg(FALSE)] fn e() { let _ = -#![attr] 0; }
    = note: outer attributes, like `#[test]`, annotate the item following them
 
 error: expected one of `!`, `.`, `::`, `;`, `?`, `else`, `{`, or an operator, found `#`
-  --> $DIR/attr-stmt-expr-attr-bad.rs:21:34
+  --> $DIR/attr-stmt-expr-attr-bad.rs:19:34
    |
 LL | #[cfg(FALSE)] fn e() { let _ = x #![attr] as Y; }
    |                                  ^ expected one of 8 possible tokens
 
 error: an inner attribute is not permitted in this context
-  --> $DIR/attr-stmt-expr-attr-bad.rs:23:35
+  --> $DIR/attr-stmt-expr-attr-bad.rs:21:35
    |
 LL | #[cfg(FALSE)] fn e() { let _ = || #![attr] foo; }
    |                                   ^^^^^^^^
@@ -92,7 +83,7 @@ LL | #[cfg(FALSE)] fn e() { let _ = || #![attr] foo; }
    = note: outer attributes, like `#[test]`, annotate the item following them
 
 error: an inner attribute is not permitted in this context
-  --> $DIR/attr-stmt-expr-attr-bad.rs:25:40
+  --> $DIR/attr-stmt-expr-attr-bad.rs:23:40
    |
 LL | #[cfg(FALSE)] fn e() { let _ = move || #![attr] foo; }
    |                                        ^^^^^^^^
@@ -101,7 +92,7 @@ LL | #[cfg(FALSE)] fn e() { let _ = move || #![attr] foo; }
    = note: outer attributes, like `#[test]`, annotate the item following them
 
 error: an inner attribute is not permitted in this context
-  --> $DIR/attr-stmt-expr-attr-bad.rs:27:35
+  --> $DIR/attr-stmt-expr-attr-bad.rs:25:35
    |
 LL | #[cfg(FALSE)] fn e() { let _ = || #![attr] {foo}; }
    |                                   ^^^^^^^^
@@ -110,7 +101,7 @@ LL | #[cfg(FALSE)] fn e() { let _ = || #![attr] {foo}; }
    = note: outer attributes, like `#[test]`, annotate the item following them
 
 error: an inner attribute is not permitted in this context
-  --> $DIR/attr-stmt-expr-attr-bad.rs:29:40
+  --> $DIR/attr-stmt-expr-attr-bad.rs:27:40
    |
 LL | #[cfg(FALSE)] fn e() { let _ = move || #![attr] {foo}; }
    |                                        ^^^^^^^^
@@ -119,19 +110,19 @@ LL | #[cfg(FALSE)] fn e() { let _ = move || #![attr] {foo}; }
    = note: outer attributes, like `#[test]`, annotate the item following them
 
 error: expected expression, found `..`
-  --> $DIR/attr-stmt-expr-attr-bad.rs:31:40
+  --> $DIR/attr-stmt-expr-attr-bad.rs:29:40
    |
 LL | #[cfg(FALSE)] fn e() { let _ = #[attr] ..#[attr] 0; }
    |                                        ^^ expected expression
 
 error: expected expression, found `..`
-  --> $DIR/attr-stmt-expr-attr-bad.rs:33:40
+  --> $DIR/attr-stmt-expr-attr-bad.rs:31:40
    |
 LL | #[cfg(FALSE)] fn e() { let _ = #[attr] ..; }
    |                                        ^^ expected expression
 
 error: an inner attribute is not permitted in this context
-  --> $DIR/attr-stmt-expr-attr-bad.rs:35:41
+  --> $DIR/attr-stmt-expr-attr-bad.rs:33:41
    |
 LL | #[cfg(FALSE)] fn e() { let _ = #[attr] &#![attr] 0; }
    |                                         ^^^^^^^^
@@ -140,7 +131,7 @@ LL | #[cfg(FALSE)] fn e() { let _ = #[attr] &#![attr] 0; }
    = note: outer attributes, like `#[test]`, annotate the item following them
 
 error: an inner attribute is not permitted in this context
-  --> $DIR/attr-stmt-expr-attr-bad.rs:37:45
+  --> $DIR/attr-stmt-expr-attr-bad.rs:35:45
    |
 LL | #[cfg(FALSE)] fn e() { let _ = #[attr] &mut #![attr] 0; }
    |                                             ^^^^^^^^
@@ -149,7 +140,7 @@ LL | #[cfg(FALSE)] fn e() { let _ = #[attr] &mut #![attr] 0; }
    = note: outer attributes, like `#[test]`, annotate the item following them
 
 error: outer attributes are not allowed on `if` and `else` branches
-  --> $DIR/attr-stmt-expr-attr-bad.rs:39:37
+  --> $DIR/attr-stmt-expr-attr-bad.rs:37:37
    |
 LL | #[cfg(FALSE)] fn e() { let _ = if 0 #[attr] {}; }
    |                                --   ^^^^^^^ -- the attributes are attached to this branch
@@ -158,7 +149,7 @@ LL | #[cfg(FALSE)] fn e() { let _ = if 0 #[attr] {}; }
    |                                the branch belongs to this `if`
 
 error: an inner attribute is not permitted in this context
-  --> $DIR/attr-stmt-expr-attr-bad.rs:41:38
+  --> $DIR/attr-stmt-expr-attr-bad.rs:39:38
    |
 LL | #[cfg(FALSE)] fn e() { let _ = if 0 {#![attr]}; }
    |                                      ^^^^^^^^
@@ -167,13 +158,13 @@ LL | #[cfg(FALSE)] fn e() { let _ = if 0 {#![attr]}; }
    = note: outer attributes, like `#[test]`, annotate the item following them
 
 error: expected one of `.`, `;`, `?`, `else`, or an operator, found `#`
-  --> $DIR/attr-stmt-expr-attr-bad.rs:43:40
+  --> $DIR/attr-stmt-expr-attr-bad.rs:41:40
    |
 LL | #[cfg(FALSE)] fn e() { let _ = if 0 {} #[attr] else {}; }
    |                                        ^ expected one of `.`, `;`, `?`, `else`, or an operator
 
 error: outer attributes are not allowed on `if` and `else` branches
-  --> $DIR/attr-stmt-expr-attr-bad.rs:45:45
+  --> $DIR/attr-stmt-expr-attr-bad.rs:43:45
    |
 LL | #[cfg(FALSE)] fn e() { let _ = if 0 {} else #[attr] {}; }
    |                                        ---- ^^^^^^^ -- the attributes are attached to this branch
@@ -182,7 +173,7 @@ LL | #[cfg(FALSE)] fn e() { let _ = if 0 {} else #[attr] {}; }
    |                                        the branch belongs to this `else`
 
 error: an inner attribute is not permitted in this context
-  --> $DIR/attr-stmt-expr-attr-bad.rs:47:46
+  --> $DIR/attr-stmt-expr-attr-bad.rs:45:46
    |
 LL | #[cfg(FALSE)] fn e() { let _ = if 0 {} else {#![attr]}; }
    |                                              ^^^^^^^^
@@ -191,7 +182,7 @@ LL | #[cfg(FALSE)] fn e() { let _ = if 0 {} else {#![attr]}; }
    = note: outer attributes, like `#[test]`, annotate the item following them
 
 error: outer attributes are not allowed on `if` and `else` branches
-  --> $DIR/attr-stmt-expr-attr-bad.rs:49:45
+  --> $DIR/attr-stmt-expr-attr-bad.rs:47:45
    |
 LL | #[cfg(FALSE)] fn e() { let _ = if 0 {} else #[attr] if 0 {}; }
    |                                        ---- ^^^^^^^ ------- the attributes are attached to this branch
@@ -200,7 +191,7 @@ LL | #[cfg(FALSE)] fn e() { let _ = if 0 {} else #[attr] if 0 {}; }
    |                                        the branch belongs to this `else`
 
 error: outer attributes are not allowed on `if` and `else` branches
-  --> $DIR/attr-stmt-expr-attr-bad.rs:51:50
+  --> $DIR/attr-stmt-expr-attr-bad.rs:49:50
    |
 LL | #[cfg(FALSE)] fn e() { let _ = if 0 {} else if 0 #[attr] {}; }
    |                                             --   ^^^^^^^ -- the attributes are attached to this branch
@@ -209,7 +200,7 @@ LL | #[cfg(FALSE)] fn e() { let _ = if 0 {} else if 0 #[attr] {}; }
    |                                             the branch belongs to this `if`
 
 error: an inner attribute is not permitted in this context
-  --> $DIR/attr-stmt-expr-attr-bad.rs:53:51
+  --> $DIR/attr-stmt-expr-attr-bad.rs:51:51
    |
 LL | #[cfg(FALSE)] fn e() { let _ = if 0 {} else if 0 {#![attr]}; }
    |                                                   ^^^^^^^^
@@ -218,7 +209,7 @@ LL | #[cfg(FALSE)] fn e() { let _ = if 0 {} else if 0 {#![attr]}; }
    = note: outer attributes, like `#[test]`, annotate the item following them
 
 error: outer attributes are not allowed on `if` and `else` branches
-  --> $DIR/attr-stmt-expr-attr-bad.rs:55:45
+  --> $DIR/attr-stmt-expr-attr-bad.rs:53:45
    |
 LL | #[cfg(FALSE)] fn e() { let _ = if let _ = 0 #[attr] {}; }
    |                                --           ^^^^^^^ -- the attributes are attached to this branch
@@ -227,7 +218,7 @@ LL | #[cfg(FALSE)] fn e() { let _ = if let _ = 0 #[attr] {}; }
    |                                the branch belongs to this `if`
 
 error: an inner attribute is not permitted in this context
-  --> $DIR/attr-stmt-expr-attr-bad.rs:57:46
+  --> $DIR/attr-stmt-expr-attr-bad.rs:55:46
    |
 LL | #[cfg(FALSE)] fn e() { let _ = if let _ = 0 {#![attr]}; }
    |                                              ^^^^^^^^
@@ -236,13 +227,13 @@ LL | #[cfg(FALSE)] fn e() { let _ = if let _ = 0 {#![attr]}; }
    = note: outer attributes, like `#[test]`, annotate the item following them
 
 error: expected one of `.`, `;`, `?`, `else`, or an operator, found `#`
-  --> $DIR/attr-stmt-expr-attr-bad.rs:59:48
+  --> $DIR/attr-stmt-expr-attr-bad.rs:57:48
    |
 LL | #[cfg(FALSE)] fn e() { let _ = if let _ = 0 {} #[attr] else {}; }
    |                                                ^ expected one of `.`, `;`, `?`, `else`, or an operator
 
 error: outer attributes are not allowed on `if` and `else` branches
-  --> $DIR/attr-stmt-expr-attr-bad.rs:61:53
+  --> $DIR/attr-stmt-expr-attr-bad.rs:59:53
    |
 LL | #[cfg(FALSE)] fn e() { let _ = if let _ = 0 {} else #[attr] {}; }
    |                                                ---- ^^^^^^^ -- the attributes are attached to this branch
@@ -251,7 +242,7 @@ LL | #[cfg(FALSE)] fn e() { let _ = if let _ = 0 {} else #[attr] {}; }
    |                                                the branch belongs to this `else`
 
 error: an inner attribute is not permitted in this context
-  --> $DIR/attr-stmt-expr-attr-bad.rs:63:54
+  --> $DIR/attr-stmt-expr-attr-bad.rs:61:54
    |
 LL | #[cfg(FALSE)] fn e() { let _ = if let _ = 0 {} else {#![attr]}; }
    |                                                      ^^^^^^^^
@@ -260,7 +251,7 @@ LL | #[cfg(FALSE)] fn e() { let _ = if let _ = 0 {} else {#![attr]}; }
    = note: outer attributes, like `#[test]`, annotate the item following them
 
 error: outer attributes are not allowed on `if` and `else` branches
-  --> $DIR/attr-stmt-expr-attr-bad.rs:65:53
+  --> $DIR/attr-stmt-expr-attr-bad.rs:63:53
    |
 LL | #[cfg(FALSE)] fn e() { let _ = if let _ = 0 {} else #[attr] if let _ = 0 {}; }
    |                                                ---- ^^^^^^^ --------------- the attributes are attached to this branch
@@ -269,7 +260,7 @@ LL | #[cfg(FALSE)] fn e() { let _ = if let _ = 0 {} else #[attr] if let _ = 0 {}
    |                                                the branch belongs to this `else`
 
 error: outer attributes are not allowed on `if` and `else` branches
-  --> $DIR/attr-stmt-expr-attr-bad.rs:67:66
+  --> $DIR/attr-stmt-expr-attr-bad.rs:65:66
    |
 LL | #[cfg(FALSE)] fn e() { let _ = if let _ = 0 {} else if let _ = 0 #[attr] {}; }
    |                                                     --           ^^^^^^^ -- the attributes are attached to this branch
@@ -278,7 +269,7 @@ LL | #[cfg(FALSE)] fn e() { let _ = if let _ = 0 {} else if let _ = 0 #[attr] {}
    |                                                     the branch belongs to this `if`
 
 error: an inner attribute is not permitted in this context
-  --> $DIR/attr-stmt-expr-attr-bad.rs:69:67
+  --> $DIR/attr-stmt-expr-attr-bad.rs:67:67
    |
 LL | #[cfg(FALSE)] fn e() { let _ = if let _ = 0 {} else if let _ = 0 {#![attr]}; }
    |                                                                   ^^^^^^^^
@@ -287,7 +278,7 @@ LL | #[cfg(FALSE)] fn e() { let _ = if let _ = 0 {} else if let _ = 0 {#![attr]}
    = note: outer attributes, like `#[test]`, annotate the item following them
 
 error: an inner attribute is not permitted following an outer attribute
-  --> $DIR/attr-stmt-expr-attr-bad.rs:72:32
+  --> $DIR/attr-stmt-expr-attr-bad.rs:70:32
    |
 LL | #[cfg(FALSE)] fn s() { #[attr] #![attr] let _ = 0; }
    |                        ------- ^^^^^^^^ not permitted following an outer attribute
@@ -298,7 +289,7 @@ LL | #[cfg(FALSE)] fn s() { #[attr] #![attr] let _ = 0; }
    = note: outer attributes, like `#[test]`, annotate the item following them
 
 error: an inner attribute is not permitted following an outer attribute
-  --> $DIR/attr-stmt-expr-attr-bad.rs:74:32
+  --> $DIR/attr-stmt-expr-attr-bad.rs:72:32
    |
 LL | #[cfg(FALSE)] fn s() { #[attr] #![attr] 0; }
    |                        ------- ^^^^^^^^ not permitted following an outer attribute
@@ -309,7 +300,7 @@ LL | #[cfg(FALSE)] fn s() { #[attr] #![attr] 0; }
    = note: outer attributes, like `#[test]`, annotate the item following them
 
 error: an inner attribute is not permitted following an outer attribute
-  --> $DIR/attr-stmt-expr-attr-bad.rs:76:32
+  --> $DIR/attr-stmt-expr-attr-bad.rs:74:32
    |
 LL | #[cfg(FALSE)] fn s() { #[attr] #![attr] foo!(); }
    |                        ------- ^^^^^^^^ ------- the inner attribute doesn't annotate this item macro invocation
@@ -325,7 +316,7 @@ LL + #[cfg(FALSE)] fn s() { #[attr] #[attr] foo!(); }
    |
 
 error: an inner attribute is not permitted following an outer attribute
-  --> $DIR/attr-stmt-expr-attr-bad.rs:78:32
+  --> $DIR/attr-stmt-expr-attr-bad.rs:76:32
    |
 LL | #[cfg(FALSE)] fn s() { #[attr] #![attr] foo![]; }
    |                        ------- ^^^^^^^^ ------- the inner attribute doesn't annotate this item macro invocation
@@ -341,7 +332,7 @@ LL + #[cfg(FALSE)] fn s() { #[attr] #[attr] foo![]; }
    |
 
 error: an inner attribute is not permitted following an outer attribute
-  --> $DIR/attr-stmt-expr-attr-bad.rs:80:32
+  --> $DIR/attr-stmt-expr-attr-bad.rs:78:32
    |
 LL | #[cfg(FALSE)] fn s() { #[attr] #![attr] foo!{}; }
    |                        ------- ^^^^^^^^ ------ the inner attribute doesn't annotate this item macro invocation
@@ -357,7 +348,7 @@ LL + #[cfg(FALSE)] fn s() { #[attr] #[attr] foo!{}; }
    |
 
 error[E0586]: inclusive range with no end
-  --> $DIR/attr-stmt-expr-attr-bad.rs:86:35
+  --> $DIR/attr-stmt-expr-attr-bad.rs:84:35
    |
 LL | #[cfg(FALSE)] fn e() { match 0 { 0..=#[attr] 10 => () } }
    |                                   ^^^ help: use `..` instead
@@ -365,13 +356,13 @@ LL | #[cfg(FALSE)] fn e() { match 0 { 0..=#[attr] 10 => () } }
    = note: inclusive ranges must be bounded at the end (`..=b` or `a..=b`)
 
 error: expected one of `=>`, `if`, or `|`, found `#`
-  --> $DIR/attr-stmt-expr-attr-bad.rs:86:38
+  --> $DIR/attr-stmt-expr-attr-bad.rs:84:38
    |
 LL | #[cfg(FALSE)] fn e() { match 0 { 0..=#[attr] 10 => () } }
    |                                      ^ expected one of `=>`, `if`, or `|`
 
 error[E0586]: inclusive range with no end
-  --> $DIR/attr-stmt-expr-attr-bad.rs:89:35
+  --> $DIR/attr-stmt-expr-attr-bad.rs:87:35
    |
 LL | #[cfg(FALSE)] fn e() { match 0 { 0..=#[attr] -10 => () } }
    |                                   ^^^ help: use `..` instead
@@ -379,19 +370,19 @@ LL | #[cfg(FALSE)] fn e() { match 0 { 0..=#[attr] -10 => () } }
    = note: inclusive ranges must be bounded at the end (`..=b` or `a..=b`)
 
 error: expected one of `=>`, `if`, or `|`, found `#`
-  --> $DIR/attr-stmt-expr-attr-bad.rs:89:38
+  --> $DIR/attr-stmt-expr-attr-bad.rs:87:38
    |
 LL | #[cfg(FALSE)] fn e() { match 0 { 0..=#[attr] -10 => () } }
    |                                      ^ expected one of `=>`, `if`, or `|`
 
 error: unexpected token: `#`
-  --> $DIR/attr-stmt-expr-attr-bad.rs:92:39
+  --> $DIR/attr-stmt-expr-attr-bad.rs:90:39
    |
 LL | #[cfg(FALSE)] fn e() { match 0 { 0..=-#[attr] 10 => () } }
    |                                       ^
 
 error[E0586]: inclusive range with no end
-  --> $DIR/attr-stmt-expr-attr-bad.rs:94:35
+  --> $DIR/attr-stmt-expr-attr-bad.rs:92:35
    |
 LL | #[cfg(FALSE)] fn e() { match 0 { 0..=#[attr] FOO => () } }
    |                                   ^^^ help: use `..` instead
@@ -399,47 +390,47 @@ LL | #[cfg(FALSE)] fn e() { match 0 { 0..=#[attr] FOO => () } }
    = note: inclusive ranges must be bounded at the end (`..=b` or `a..=b`)
 
 error: expected one of `=>`, `if`, or `|`, found `#`
-  --> $DIR/attr-stmt-expr-attr-bad.rs:94:38
+  --> $DIR/attr-stmt-expr-attr-bad.rs:92:38
    |
 LL | #[cfg(FALSE)] fn e() { match 0 { 0..=#[attr] FOO => () } }
    |                                      ^ expected one of `=>`, `if`, or `|`
 
 error: unexpected token: `#`
-  --> $DIR/attr-stmt-expr-attr-bad.rs:98:34
+  --> $DIR/attr-stmt-expr-attr-bad.rs:96:34
    |
 LL | #[cfg(FALSE)] fn e() { let _ = x.#![attr]foo(); }
    |                                  ^
 
 error: expected one of `.`, `;`, `?`, `else`, or an operator, found `#`
-  --> $DIR/attr-stmt-expr-attr-bad.rs:98:34
+  --> $DIR/attr-stmt-expr-attr-bad.rs:96:34
    |
 LL | #[cfg(FALSE)] fn e() { let _ = x.#![attr]foo(); }
    |                                  ^ expected one of `.`, `;`, `?`, `else`, or an operator
 
 error: unexpected token: `#`
-  --> $DIR/attr-stmt-expr-attr-bad.rs:101:34
+  --> $DIR/attr-stmt-expr-attr-bad.rs:99:34
    |
 LL | #[cfg(FALSE)] fn e() { let _ = x.#[attr]foo(); }
    |                                  ^
 
 error: expected one of `.`, `;`, `?`, `else`, or an operator, found `#`
-  --> $DIR/attr-stmt-expr-attr-bad.rs:101:34
+  --> $DIR/attr-stmt-expr-attr-bad.rs:99:34
    |
 LL | #[cfg(FALSE)] fn e() { let _ = x.#[attr]foo(); }
    |                                  ^ expected one of `.`, `;`, `?`, `else`, or an operator
 
 error: expected statement after outer attribute
-  --> $DIR/attr-stmt-expr-attr-bad.rs:106:37
+  --> $DIR/attr-stmt-expr-attr-bad.rs:104:37
    |
 LL | #[cfg(FALSE)] fn e() { { fn foo() { #[attr]; } } }
    |                                     ^^^^^^^
 
 error: expected statement after outer attribute
-  --> $DIR/attr-stmt-expr-attr-bad.rs:108:37
+  --> $DIR/attr-stmt-expr-attr-bad.rs:106:37
    |
 LL | #[cfg(FALSE)] fn e() { { fn foo() { #[attr] } } }
    |                                     ^^^^^^^
 
-error: aborting due to 53 previous errors
+error: aborting due to 52 previous errors
 
 For more information about this error, try `rustc --explain E0586`.

tests/ui/parser/issues/issue-65846-rollback-gating-failing-matcher.rs

@@ -5,11 +5,17 @@
 
 #[allow(unused_macro_rules)]
 macro_rules! m {
-    ($e:expr) => { 0 }; // This fails on the input below due to `, foo`.
-    ($e:expr,) => { 1 }; // This also fails to match due to `foo`.
-    (box $e:expr, foo) => { 2 }; // Successful matcher, we should get `2`.
+    ($e:expr) => {
+        0
+    }; // This fails on the input below due to `, foo`.
+    ($e:expr,) => {
+        1
+    }; // This also fails to match due to `foo`.
+    (do yeet $e:expr, foo) => {
+        2
+    }; // Successful matcher, we should get `2`.
 }
 
 fn main() {
-    assert_eq!(2, m!(box 42, foo));
+    assert_eq!(2, m!(do yeet 42, foo));
 }

tests/ui/reachable/expr_box.rs

@@ -1,8 +0,0 @@
-#![feature(box_syntax)]
-#![allow(unused_variables)]
-#![deny(unreachable_code)]
-
-fn main() {
-    let x = box return; //~ ERROR unreachable
-    println!("hi");
-}

tests/ui/reachable/expr_box.stderr

@@ -1,17 +0,0 @@
-error: unreachable expression
-  --> $DIR/expr_box.rs:6:13
-   |
-LL |     let x = box return;
-   |             ^^^^------
-   |             |   |
-   |             |   any code following this expression is unreachable
-   |             unreachable expression
-   |
-note: the lint level is defined here
-  --> $DIR/expr_box.rs:3:9
-   |
-LL | #![deny(unreachable_code)]
-   |         ^^^^^^^^^^^^^^^^
-
-error: aborting due to previous error
-

tests/ui/static/static-mut-not-constant.rs

@@ -1,6 +1,4 @@
-#![feature(box_syntax)]
-
-static mut a: Box<isize> = box 3;
-//~^ ERROR allocations are not allowed in statics
+static mut a: Box<isize> = Box::new(3);
+//~^ ERROR cannot call non-const fn
 
 fn main() {}

tests/ui/static/static-mut-not-constant.stderr

@@ -1,9 +1,12 @@
-error[E0010]: allocations are not allowed in statics
-  --> $DIR/static-mut-not-constant.rs:3:28
+error[E0015]: cannot call non-const fn `Box::<isize>::new` in statics
+  --> $DIR/static-mut-not-constant.rs:1:28
    |
-LL | static mut a: Box<isize> = box 3;
-   |                            ^^^^^ allocation not allowed in statics
+LL | static mut a: Box<isize> = Box::new(3);
+   |                            ^^^^^^^^^^^
+   |
+   = note: calls in statics are limited to constant functions, tuple structs and tuple variants
+   = note: consider wrapping this expression in `Lazy::new(|| ...)` from the `once_cell` crate: https://crates.io/crates/once_cell
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0010`.
+For more information about this error, try `rustc --explain E0015`.

tests/ui/typeck/issue-105946.rs

@@ -3,10 +3,8 @@ fn digit() -> str {
     //~^ ERROR: mismatched types [E0308]
 }
 fn main() {
-    let [_y..] = [box 1, box 2];
+    let [_y..] = [Box::new(1), Box::new(2)];
     //~^ ERROR: cannot find value `_y` in this scope [E0425]
     //~| ERROR: `X..` patterns in slices are experimental [E0658]
-    //~| ERROR: box expression syntax is experimental; you can call `Box::new` instead [E0658]
-    //~| ERROR: box expression syntax is experimental; you can call `Box::new` instead [E0658]
     //~| ERROR: pattern requires 1 element but array has 2 [E0527]
 }

tests/ui/typeck/issue-105946.stderr

@@ -1,38 +1,20 @@
 error[E0425]: cannot find value `_y` in this scope
   --> $DIR/issue-105946.rs:6:10
    |
-LL |     let [_y..] = [box 1, box 2];
+LL |     let [_y..] = [Box::new(1), Box::new(2)];
    |          ^^ not found in this scope
 
 error[E0658]: `X..` patterns in slices are experimental
   --> $DIR/issue-105946.rs:6:10
    |
-LL |     let [_y..] = [box 1, box 2];
+LL |     let [_y..] = [Box::new(1), Box::new(2)];
    |          ^^^^
    |
    = note: see issue #67264 <https://github.com/rust-lang/rust/issues/67264> for more information
    = help: add `#![feature(half_open_range_patterns_in_slices)]` to the crate attributes to enable
 
-error[E0658]: box expression syntax is experimental; you can call `Box::new` instead
-  --> $DIR/issue-105946.rs:6:19
-   |
-LL |     let [_y..] = [box 1, box 2];
-   |                   ^^^^^
-   |
-   = note: see issue #49733 <https://github.com/rust-lang/rust/issues/49733> for more information
-   = help: add `#![feature(box_syntax)]` to the crate attributes to enable
-
-error[E0658]: box expression syntax is experimental; you can call `Box::new` instead
-  --> $DIR/issue-105946.rs:6:26
-   |
-LL |     let [_y..] = [box 1, box 2];
-   |                          ^^^^^
-   |
-   = note: see issue #49733 <https://github.com/rust-lang/rust/issues/49733> for more information
-   = help: add `#![feature(box_syntax)]` to the crate attributes to enable
-
 error[E0308]: mismatched types
-  --> $DIR/issue-105946.rs:2:10
+  --> $DIR/issue-105946.rs:2:12
    |
 LL |     return {};
    |            ^^ expected `str`, found `()`
@@ -40,10 +22,10 @@ LL |   return {};
 error[E0527]: pattern requires 1 element but array has 2
   --> $DIR/issue-105946.rs:6:9
    |
-LL |     let [_y..] = [box 1, box 2];
+LL |     let [_y..] = [Box::new(1), Box::new(2)];
    |         ^^^^^^ expected 2 elements
 
-error: aborting due to 6 previous errors
+error: aborting due to 4 previous errors
 
 Some errors have detailed explanations: E0308, E0425, E0527, E0658.
 For more information about an error, try `rustc --explain E0308`.

tests/ui/typeck/issue-87935-unsized-box-expr.rs

@@ -1,10 +0,0 @@
-#![feature(box_syntax)]
-// Box expression needs to be movable, and hence has to be of a Sized type.
-fn main() {
-    let _x: Box<[u32]> = box { loop {} };
-    //~^ ERROR: the size for values of type `[u32]` cannot be known at compilation time
-
-    // Check that a deduced size does not cause issues.
-    let _y: Box<[u32]> = box [];
-    let _z: Box<[u32; 0]> = box { loop {} };
-}

tests/ui/typeck/issue-87935-unsized-box-expr.stderr

@@ -1,12 +0,0 @@
-error[E0277]: the size for values of type `[u32]` cannot be known at compilation time
-  --> $DIR/issue-87935-unsized-box-expr.rs:4:30
-   |
-LL |     let _x: Box<[u32]> = box { loop {} };
-   |                              ^^^^^^^^^^^ doesn't have a size known at compile-time
-   |
-   = help: the trait `Sized` is not implemented for `[u32]`
-   = note: the type of a box expression must have a statically known size
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0277`.

tests/ui/unpretty/box.rs

@@ -0,0 +1,9 @@
+// compile-flags: -Zunpretty=hir
+// check-pass
+
+#![feature(stmt_expr_attributes, rustc_attrs)]
+
+fn main() {
+    let _ = #[rustc_box]
+    Box::new(1);
+}

tests/ui/unpretty/box.stdout

@@ -0,0 +1,14 @@
+// compile-flags: -Zunpretty=hir
+// check-pass
+
+#![feature(stmt_expr_attributes, rustc_attrs)]
+#[prelude_import]
+use ::std::prelude::rust_2015::*;
+#[macro_use]
+extern crate std;
+
+fn main() {
+        let _ =
+            #[rustc_box]
+            Box::new (1);
+    }