unnecessary_operation: make test rustfixable

tests/ui/unnecessary_operation.fixed

@@ -0,0 +1,79 @@
+// run-rustfix
+
+#![feature(box_syntax)]
+#![allow(clippy::deref_addrof, dead_code, unused, clippy::no_effect)]
+#![warn(clippy::unnecessary_operation)]
+
+struct Tuple(i32);
+struct Struct {
+    field: i32,
+}
+enum Enum {
+    Tuple(i32),
+    Struct { field: i32 },
+}
+struct DropStruct {
+    field: i32,
+}
+impl Drop for DropStruct {
+    fn drop(&mut self) {}
+}
+struct DropTuple(i32);
+impl Drop for DropTuple {
+    fn drop(&mut self) {}
+}
+enum DropEnum {
+    Tuple(i32),
+    Struct { field: i32 },
+}
+impl Drop for DropEnum {
+    fn drop(&mut self) {}
+}
+struct FooString {
+    s: String,
+}
+
+fn get_number() -> i32 {
+    0
+}
+
+fn get_usize() -> usize {
+    0
+}
+fn get_struct() -> Struct {
+    Struct { field: 0 }
+}
+fn get_drop_struct() -> DropStruct {
+    DropStruct { field: 0 }
+}
+
+fn main() {
+    get_number();
+    get_number();
+    get_struct();
+    get_number();
+    get_number();
+    5;get_number();
+    get_number();
+    get_number();
+    5;6;get_number();
+    get_number();
+    get_number();
+    get_number();
+    5;get_number();
+    42;get_number();
+    [42, 55];get_usize();
+    42;get_number();
+    get_number();
+    [42; 55];get_usize();
+    get_number();
+    String::from("blah");
+
+    // Do not warn
+    DropTuple(get_number());
+    DropStruct { field: get_number() };
+    DropStruct { field: get_number() };
+    DropStruct { ..get_drop_struct() };
+    DropEnum::Tuple(get_number());
+    DropEnum::Struct { field: get_number() };
+}

tests/ui/unnecessary_operation.rs

@@ -1,5 +1,7 @@
+// run-rustfix
+
 #![feature(box_syntax)]
-#![allow(clippy::deref_addrof)]
+#![allow(clippy::deref_addrof, dead_code, unused, clippy::no_effect)]
 #![warn(clippy::unnecessary_operation)]
 
 struct Tuple(i32);
@@ -34,6 +36,10 @@ struct FooString {
 fn get_number() -> i32 {
     0
 }
+
+fn get_usize() -> usize {
+    0
+}
 fn get_struct() -> Struct {
     Struct { field: 0 }
 }
@@ -56,10 +62,10 @@ fn main() {
     ..get_number();
     5..get_number();
     [42, get_number()];
-    [42, 55][get_number() as usize];
+    [42, 55][get_usize()];
     (42, get_number()).1;
     [get_number(); 55];
-    [42; 55][get_number() as usize];
+    [42; 55][get_usize()];
     {
         get_number()
     };

tests/ui/unnecessary_operation.stderr

@@ -1,5 +1,5 @@
 error: statement can be reduced
-  --> $DIR/unnecessary_operation.rs:45:5
+  --> $DIR/unnecessary_operation.rs:51:5
    |
 LL |     Tuple(get_number());
    |     ^^^^^^^^^^^^^^^^^^^^ help: replace it with: `get_number();`
@@ -7,109 +7,109 @@ LL |     Tuple(get_number());
    = note: `-D clippy::unnecessary-operation` implied by `-D warnings`
 
 error: statement can be reduced
-  --> $DIR/unnecessary_operation.rs:46:5
+  --> $DIR/unnecessary_operation.rs:52:5
    |
 LL |     Struct { field: get_number() };
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `get_number();`
 
 error: statement can be reduced
-  --> $DIR/unnecessary_operation.rs:47:5
+  --> $DIR/unnecessary_operation.rs:53:5
    |
 LL |     Struct { ..get_struct() };
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `get_struct();`
 
 error: statement can be reduced
-  --> $DIR/unnecessary_operation.rs:48:5
+  --> $DIR/unnecessary_operation.rs:54:5
    |
 LL |     Enum::Tuple(get_number());
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `get_number();`
 
 error: statement can be reduced
-  --> $DIR/unnecessary_operation.rs:49:5
+  --> $DIR/unnecessary_operation.rs:55:5
    |
 LL |     Enum::Struct { field: get_number() };
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `get_number();`
 
 error: statement can be reduced
-  --> $DIR/unnecessary_operation.rs:50:5
+  --> $DIR/unnecessary_operation.rs:56:5
    |
 LL |     5 + get_number();
    |     ^^^^^^^^^^^^^^^^^ help: replace it with: `5;get_number();`
 
 error: statement can be reduced
-  --> $DIR/unnecessary_operation.rs:51:5
+  --> $DIR/unnecessary_operation.rs:57:5
    |
 LL |     *&get_number();
    |     ^^^^^^^^^^^^^^^ help: replace it with: `get_number();`
 
 error: statement can be reduced
-  --> $DIR/unnecessary_operation.rs:52:5
+  --> $DIR/unnecessary_operation.rs:58:5
    |
 LL |     &get_number();
    |     ^^^^^^^^^^^^^^ help: replace it with: `get_number();`
 
 error: statement can be reduced
-  --> $DIR/unnecessary_operation.rs:53:5
+  --> $DIR/unnecessary_operation.rs:59:5
    |
 LL |     (5, 6, get_number());
    |     ^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `5;6;get_number();`
 
 error: statement can be reduced
-  --> $DIR/unnecessary_operation.rs:54:5
+  --> $DIR/unnecessary_operation.rs:60:5
    |
 LL |     box get_number();
    |     ^^^^^^^^^^^^^^^^^ help: replace it with: `get_number();`
 
 error: statement can be reduced
-  --> $DIR/unnecessary_operation.rs:55:5
+  --> $DIR/unnecessary_operation.rs:61:5
    |
 LL |     get_number()..;
    |     ^^^^^^^^^^^^^^^ help: replace it with: `get_number();`
 
 error: statement can be reduced
-  --> $DIR/unnecessary_operation.rs:56:5
+  --> $DIR/unnecessary_operation.rs:62:5
    |
 LL |     ..get_number();
    |     ^^^^^^^^^^^^^^^ help: replace it with: `get_number();`
 
 error: statement can be reduced
-  --> $DIR/unnecessary_operation.rs:57:5
+  --> $DIR/unnecessary_operation.rs:63:5
    |
 LL |     5..get_number();
    |     ^^^^^^^^^^^^^^^^ help: replace it with: `5;get_number();`
 
 error: statement can be reduced
-  --> $DIR/unnecessary_operation.rs:58:5
+  --> $DIR/unnecessary_operation.rs:64:5
    |
 LL |     [42, get_number()];
    |     ^^^^^^^^^^^^^^^^^^^ help: replace it with: `42;get_number();`
 
 error: statement can be reduced
-  --> $DIR/unnecessary_operation.rs:59:5
+  --> $DIR/unnecessary_operation.rs:65:5
    |
-LL |     [42, 55][get_number() as usize];
+LL |     [42, 55][get_usize()];
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `[42, 55];get_number() as usize;`
+   |     ^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `[42, 55];get_usize();`
 
 error: statement can be reduced
-  --> $DIR/unnecessary_operation.rs:60:5
+  --> $DIR/unnecessary_operation.rs:66:5
    |
 LL |     (42, get_number()).1;
    |     ^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `42;get_number();`
 
 error: statement can be reduced
-  --> $DIR/unnecessary_operation.rs:61:5
+  --> $DIR/unnecessary_operation.rs:67:5
    |
 LL |     [get_number(); 55];
    |     ^^^^^^^^^^^^^^^^^^^ help: replace it with: `get_number();`
 
 error: statement can be reduced
-  --> $DIR/unnecessary_operation.rs:62:5
+  --> $DIR/unnecessary_operation.rs:68:5
    |
-LL |     [42; 55][get_number() as usize];
+LL |     [42; 55][get_usize()];
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `[42; 55];get_number() as usize;`
+   |     ^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `[42; 55];get_usize();`
 
 error: statement can be reduced
-  --> $DIR/unnecessary_operation.rs:63:5
+  --> $DIR/unnecessary_operation.rs:69:5
    |
 LL | /     {
 LL | |         get_number()
@@ -117,7 +117,7 @@ LL | |     };
    | |______^ help: replace it with: `get_number();`
 
 error: statement can be reduced
-  --> $DIR/unnecessary_operation.rs:66:5
+  --> $DIR/unnecessary_operation.rs:72:5
    |
 LL | /     FooString {
 LL | |         s: String::from("blah"),