rust/tests/ui/async-await/issues/issue-102206.stderr

error[E0308]: mismatched types
  --> $DIR/issue-102206.rs:6:27
   |
LL |     std::mem::size_of_val(foo());
   |     --------------------- ^^^^^
   |     |                     |
   |     |                     expected `&_`, found future
   |     |                     help: consider borrowing here: `&foo()`
   |     arguments to this function are incorrect
   |
note: function defined here
  --> $SRC_DIR/core/src/mem/mod.rs:LL:COL

error: aborting due to previous error

For more information about this error, try `rustc --explain E0308`.
Add regression test for #102206 Signed-off-by: Yuki Okushi <jtitor@2k36.org> 2022-12-20 03:24:04 -06:00			`error[E0308]: mismatched types`
			`--> $DIR/issue-102206.rs:6:27`
			`\|`
			`LL \| std::mem::size_of_val(foo());`
			`\| --------------------- ^^^^^`
			`\| \| \|`
fix: improve the suggestion on future not awaited Considering the following code ```rust fn foo() -> u8 { async fn async_fn() -> u8 { 22 } async_fn() } fn main() {} ``` the error generated before this commit from the compiler is ``` ➜ rust git:(macros/async_fn_suggestion) ✗ rustc test.rs --edition 2021 error[E0308]: mismatched types --> test.rs:4:5 \| 1 \| fn foo() -> u8 { \| -- expected `u8` because of return type ... 4 \| async_fn() \| ^^^^^^^^^^ expected `u8`, found opaque type \| = note: expected type `u8` found opaque type `impl Future<Output = u8>` help: consider `await`ing on the `Future` \| 4 \| async_fn().await \| ++++++ error: aborting due to previous error ``` In this case the error is nor perfect, and can confuse the user that do not know that the opaque type is the future. So this commit will propose (and conclude the work start in https://github.com/rust-lang/rust/issues/80658) to change the string `opaque type` to `future` when applicable and also remove the Expected vs Received note by adding a more specific one regarding the async function that return a future type. So the new error emitted by the compiler is ``` error[E0308]: mismatched types --> test.rs:4:5 \| 1 \| fn foo() -> u8 { \| -- expected `u8` because of return type ... 4 \| async_fn() \| ^^^^^^^^^^ expected `u8`, found future \| note: calling an async function returns a future --> test.rs:4:5 \| 4 \| async_fn() \| ^^^^^^^^^^ help: consider `await`ing on the `Future` \| 4 \| async_fn().await \| ++++++ error: aborting due to previous error ``` Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> 2023-02-10 12:03:54 -06:00			\| \| expected `&_`, found future
Add regression test for #102206 Signed-off-by: Yuki Okushi <jtitor@2k36.org> 2022-12-20 03:24:04 -06:00			\| \| help: consider borrowing here: `&foo()`
			`\| arguments to this function are incorrect`
			`\|`
			`note: function defined here`
			`--> $SRC_DIR/core/src/mem/mod.rs:LL:COL`

			`error: aborting due to previous error`

			For more information about this error, try `rustc --explain E0308`.