Revert "Auto merge of #86853 - usbalbin:const_try, r=oli-obk"

This reverts commit c6007fdc70, reversing
changes made to 69c1c6a173.

library/core/src/convert/mod.rs

@@ -532,10 +532,9 @@ where
 
 // From implies Into
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_const_unstable(feature = "const_convert", issue = "88674")]
-impl<T, U> const Into<U> for T
+impl<T, U> Into<U> for T
 where
-    U: ~const From<T>,
+    U: From<T>,
 {
     fn into(self) -> U {
         U::from(self)
@@ -544,8 +543,7 @@ where
 
 // From (and thus Into) is reflexive
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_const_unstable(feature = "const_convert", issue = "88674")]
-impl<T> const From<T> for T {
+impl<T> From<T> for T {
     fn from(t: T) -> T {
         t
     }

library/core/src/lib.rs

@@ -82,7 +82,6 @@
 #![feature(const_float_bits_conv)]
 #![feature(const_float_classify)]
 #![feature(const_heap)]
-#![feature(const_convert)]
 #![feature(const_inherent_unchecked_arith)]
 #![feature(const_int_unchecked_arith)]
 #![feature(const_intrinsic_copy)]

library/core/src/option.rs

@@ -2019,8 +2019,7 @@ impl<A, V: FromIterator<A>> FromIterator<Option<A>> for Option<V> {
 }
 
 #[unstable(feature = "try_trait_v2", issue = "84277")]
-#[rustc_const_unstable(feature = "const_convert", issue = "88674")]
-impl<T> const ops::Try for Option<T> {
+impl<T> ops::Try for Option<T> {
     type Output = T;
     type Residual = Option<convert::Infallible>;
 
@@ -2039,8 +2038,7 @@ impl<T> const ops::Try for Option<T> {
 }
 
 #[unstable(feature = "try_trait_v2", issue = "84277")]
-#[rustc_const_unstable(feature = "const_convert", issue = "88674")]
-impl<T> const ops::FromResidual for Option<T> {
+impl<T> ops::FromResidual for Option<T> {
     #[inline]
     fn from_residual(residual: Option<convert::Infallible>) -> Self {
         match residual {

library/core/src/result.rs

@@ -1889,8 +1889,7 @@ impl<A, E, V: FromIterator<A>> FromIterator<Result<A, E>> for Result<V, E> {
 }
 
 #[unstable(feature = "try_trait_v2", issue = "84277")]
-#[rustc_const_unstable(feature = "const_convert", issue = "88674")]
-impl<T, E> const ops::Try for Result<T, E> {
+impl<T, E> ops::Try for Result<T, E> {
     type Output = T;
     type Residual = Result<convert::Infallible, E>;
 
@@ -1909,10 +1908,7 @@ impl<T, E> const ops::Try for Result<T, E> {
 }
 
 #[unstable(feature = "try_trait_v2", issue = "84277")]
-#[rustc_const_unstable(feature = "const_convert", issue = "88674")]
-impl<T, E, F: ~const From<E>> const ops::FromResidual<Result<convert::Infallible, E>>
-    for Result<T, F>
-{
+impl<T, E, F: From<E>> ops::FromResidual<Result<convert::Infallible, E>> for Result<T, F> {
     #[inline]
     fn from_residual(residual: Result<convert::Infallible, E>) -> Self {
         match residual {

library/core/tests/convert.rs

@@ -1,16 +0,0 @@
-#[test]
-fn convert() {
-    const fn from(x: i32) -> i32 {
-        i32::from(x)
-    }
-
-    const FOO: i32 = from(42);
-    assert_eq!(FOO, 42);
-
-    const fn into(x: Vec<String>) -> Vec<String> {
-        x.into()
-    }
-
-    const BAR: Vec<String> = into(Vec::new());
-    assert_eq!(BAR, Vec::<String>::new());
-}

library/core/tests/lib.rs

@@ -9,13 +9,12 @@
 #![feature(cfg_target_has_atomic)]
 #![feature(const_assume)]
 #![feature(const_cell_into_inner)]
-#![feature(const_convert)]
 #![feature(const_maybe_uninit_assume_init)]
-#![feature(const_num_from_num)]
 #![feature(const_ptr_read)]
 #![feature(const_ptr_write)]
 #![feature(const_ptr_offset)]
 #![feature(const_trait_impl)]
+#![feature(const_num_from_num)]
 #![feature(core_intrinsics)]
 #![feature(core_private_bignum)]
 #![feature(core_private_diy_float)]
@@ -84,7 +83,6 @@ mod char;
 mod clone;
 mod cmp;
 mod const_ptr;
-mod convert;
 mod fmt;
 mod hash;
 mod intrinsics;

src/test/ui/consts/try-operator.rs

@@ -1,23 +0,0 @@
-// run-pass
-
-#![feature(try_trait_v2)]
-#![feature(const_trait_impl)]
-#![feature(const_try)]
-#![feature(const_convert)]
-
-fn main() {
-    const fn result() -> Result<bool, ()> {
-        Err(())?;
-        Ok(true)
-    }
-
-    const FOO: Result<bool, ()> = result();
-    assert_eq!(Err(()), FOO);
-
-    const fn option() -> Option<()> {
-        None?;
-        Some(())
-    }
-    const BAR: Option<()> = option();
-    assert_eq!(None, BAR);
-}