bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Allow coercing functions whose signature differs in opaque types in their defining scope into a shared function pointer type

Browse source
This commit is contained in:
Oli Scherer 2024-04-23 14:38:17 +00:00
parent a18f043033
commit c24148ef7b
3 changed files with 4 additions and 43 deletions
Download patch file Download diff file Expand all files Collapse all files

2
compiler/rustc_hir_typeck/src/coercion.rs
View file

@ -1189,7 +1189,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
let sig = self
.at(cause, self.param_env)
.trace(prev_ty, new_ty)
.lub(DefineOpaqueTypes::No, a_sig, b_sig)
.lub(DefineOpaqueTypes::Yes, a_sig, b_sig)
.map(|ok| self.register_infer_ok_obligations(ok))?;
// Reify both sides and return the reified fn pointer type.

4
tests/ui/fn/fn_def_opaque_coercion_to_fn_ptr.rs
View file

@ -34,7 +34,7 @@ type J = impl Sized;
fn j(a: J) {
let x = match true {
true => bar::<J>,
false => foo::<()>, //~ ERROR: incompatible types
false => foo::<()>,
};
x(a);
x(());
@ -49,7 +49,7 @@ fn k() -> impl Sized {
let f = foo;
bind(k(), f)
}
false => bar::<()>, //~ ERROR: incompatible types
false => bar::<()>,
};
todo!()
}

41
tests/ui/fn/fn_def_opaque_coercion_to_fn_ptr.stderr
View file

@ -33,45 +33,6 @@ help: use parentheses to call this function
LL | x = foo::<I>(/* I */);
| +++++++++
error[E0308]: `match` arms have incompatible types
--> $DIR/fn_def_opaque_coercion_to_fn_ptr.rs:37:18
|
LL | type J = impl Sized;
| ---------- the expected opaque type
...
LL | let x = match true {
| _____________-
LL | | true => bar::<J>,
| | -------- this is found to be of type `fn(J) -> J {bar::<J>}`
LL | | false => foo::<()>,
| | ^^^^^^^^^ expected opaque type, found `()`
LL | | };
| |_____- `match` arms have incompatible types
|
= note: expected fn item `fn(J) -> J {bar::<J>}`
found fn item `fn(()) {foo::<()>}`
error[E0308]: `match` arms have incompatible types
--> $DIR/fn_def_opaque_coercion_to_fn_ptr.rs:52:18
|
LL | fn k() -> impl Sized {
| ---------- the expected opaque type
...
LL | let x = match true {
| _____________-
LL | | true => {
LL | | let f = foo;
LL | | bind(k(), f)
| | ------------ this is found to be of type `fn(impl Sized) -> impl Sized {foo::<impl Sized>}`
LL | | }
LL | | false => bar::<()>,
| | ^^^^^^^^^ expected opaque type, found `()`
LL | | };
| |_____- `match` arms have incompatible types
|
= note: expected fn item `fn(impl Sized) -> impl Sized {foo::<impl Sized>}`
found fn item `fn(()) {bar::<()>}`
error: aborting due to 4 previous errors
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0308`.