mikros/rust
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Make suggestion more complete

Browse Source
This commit is contained in:
Esteban Küber 2020-08-18 16:44:45 -07:00
parent ff297fafbf
commit 5d2a935e6c
5 changed files with 75 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
compiler/rustc_infer/src/infer/error_reporting/mod.rs
View File

@ -749,7 +749,7 @@ fn suggest_boxing_for_return_impl_trait(
})
.collect::<Vec<_>>();
err.multipart_suggestion(
"if you change the return type to expect trait objects box the returned expressions",
"if you change the return type to expect trait objects, box the returned expressions",
sugg,
Applicability::MaybeIncorrect,
);

21
compiler/rustc_typeck/src/check/coercion.rs
View File

@ -1459,7 +1459,7 @@ fn report_return_mismatched_types<'a>(
}
}
if let (Some(sp), Some(fn_output)) = (fcx.ret_coercion_span.borrow().as_ref(), fn_output) {
self.add_impl_trait_explanation(&mut err, fcx, expected, *sp, fn_output);
self.add_impl_trait_explanation(&mut err, cause, fcx, expected, *sp, fn_output);
}
err
}
@ -1467,6 +1467,7 @@ fn report_return_mismatched_types<'a>(
fn add_impl_trait_explanation<'a>(
&self,
err: &mut DiagnosticBuilder<'a>,
cause: &ObligationCause<'tcx>,
fcx: &FnCtxt<'a, 'tcx>,
expected: Ty<'tcx>,
sp: Span,
@ -1531,6 +1532,22 @@ fn add_impl_trait_explanation<'a>(
],
Applicability::MachineApplicable,
);
let sugg = vec![sp, cause.span]
.into_iter()
.flat_map(|sp| {
vec![
(sp.shrink_to_lo(), "Box::new(".to_string()),
(sp.shrink_to_hi(), ")".to_string()),
]
.into_iter()
})
.collect::<Vec<_>>();
err.multipart_suggestion(
"if you change the return type to expect trait objects, box the returned \
expressions",
sugg,
Applicability::MaybeIncorrect,
);
} else {
err.help(&format!(
"if the trait `{}` were object safe, you could return a boxed trait object",
@ -1539,7 +1556,7 @@ fn add_impl_trait_explanation<'a>(
}
err.note(trait_obj_msg);
}
err.help("alternatively, create a new `enum` with a variant for each returned type");
err.help("you could instead create a new `enum` with a variant for each returned type");
}
fn is_return_ty_unsized(&self, fcx: &FnCtxt<'a, 'tcx>, blk_id: hir::HirId) -> bool {

2
src/test/ui/impl-trait/equality.stderr
View File

@ -23,7 +23,7 @@ LL | 0_u32
= note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits>
= help: if the trait `Foo` were object safe, you could return a boxed trait object
= note: for information on trait objects, see <https://doc.rust-lang.org/book/ch17-02-trait-objects.html#using-trait-objects-that-allow-for-values-of-different-types>
= help: alternatively, create a new `enum` with a variant for each returned type
= help: you could instead create a new `enum` with a variant for each returned type
error[E0277]: cannot add `impl Foo` to `u32`
--> $DIR/equality.rs:24:11

10
src/test/ui/impl-trait/object-unsafe-trait-in-return-position-impl-trait.stderr
View File

@ -14,7 +14,7 @@ LL | B
= note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits>
= help: if the trait `NotObjectSafe` were object safe, you could return a boxed trait object
= note: for information on trait objects, see <https://doc.rust-lang.org/book/ch17-02-trait-objects.html#using-trait-objects-that-allow-for-values-of-different-types>
= help: alternatively, create a new `enum` with a variant for each returned type
= help: you could instead create a new `enum` with a variant for each returned type
error[E0308]: mismatched types
--> $DIR/object-unsafe-trait-in-return-position-impl-trait.rs:43:5
@ -31,11 +31,17 @@ LL | B
= note: to return `impl Trait`, all returned values must be of the same type
= note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits>
= note: for information on trait objects, see <https://doc.rust-lang.org/book/ch17-02-trait-objects.html#using-trait-objects-that-allow-for-values-of-different-types>
= help: alternatively, create a new `enum` with a variant for each returned type
= help: you could instead create a new `enum` with a variant for each returned type
help: you could change the return type to be a boxed trait object
|
LL | fn cat() -> Box<dyn ObjectSafe> {
| ^^^^^^^ ^
help: if you change the return type to expect trait objects, box the returned expressions
|
LL | return Box::new(A);
LL | }
LL | Box::new(B)
|
error: aborting due to 2 previous errors

54
src/test/ui/point-to-type-err-cause-on-impl-trait-return.stderr
View File

@ -13,11 +13,17 @@ LL | 1u32
= note: to return `impl Trait`, all returned values must be of the same type
= note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits>
= note: for information on trait objects, see <https://doc.rust-lang.org/book/ch17-02-trait-objects.html#using-trait-objects-that-allow-for-values-of-different-types>
= help: alternatively, create a new `enum` with a variant for each returned type
= help: you could instead create a new `enum` with a variant for each returned type
help: you could change the return type to be a boxed trait object
|
LL | fn foo() -> Box<dyn std::fmt::Display> {
| ^^^^^^^ ^
help: if you change the return type to expect trait objects, box the returned expressions
|
LL | return Box::new(0i32);
LL | }
LL | Box::new(1u32)
|
error[E0308]: mismatched types
--> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:12:16
@ -34,11 +40,17 @@ LL | return 1u32;
= note: to return `impl Trait`, all returned values must be of the same type
= note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits>
= note: for information on trait objects, see <https://doc.rust-lang.org/book/ch17-02-trait-objects.html#using-trait-objects-that-allow-for-values-of-different-types>
= help: alternatively, create a new `enum` with a variant for each returned type
= help: you could instead create a new `enum` with a variant for each returned type
help: you could change the return type to be a boxed trait object
|
LL | fn bar() -> Box<dyn std::fmt::Display> {
| ^^^^^^^ ^
help: if you change the return type to expect trait objects, box the returned expressions
|
LL | return Box::new(0i32);
LL | } else {
LL | return Box::new(1u32);
|
error[E0308]: mismatched types
--> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:20:9
@ -55,11 +67,17 @@ LL | 1u32
= note: to return `impl Trait`, all returned values must be of the same type
= note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits>
= note: for information on trait objects, see <https://doc.rust-lang.org/book/ch17-02-trait-objects.html#using-trait-objects-that-allow-for-values-of-different-types>
= help: alternatively, create a new `enum` with a variant for each returned type
= help: you could instead create a new `enum` with a variant for each returned type
help: you could change the return type to be a boxed trait object
|
LL | fn baz() -> Box<dyn std::fmt::Display> {
| ^^^^^^^ ^
help: if you change the return type to expect trait objects, box the returned expressions
|
LL | return Box::new(0i32);
LL | } else {
LL | Box::new(1u32)
|
error[E0308]: `if` and `else` have incompatible types
--> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:28:9
@ -77,7 +95,7 @@ help: you could change the return type to be a boxed trait object
|
LL | fn qux() -> Box<dyn std::fmt::Display> {
| ^^^^^^^ ^
help: if you change the return type to expect trait objects box the returned expressions
help: if you change the return type to expect trait objects, box the returned expressions
|
LL | Box::new(0i32)
LL | } else {
@ -98,11 +116,16 @@ LL | _ => 1u32,
= note: to return `impl Trait`, all returned values must be of the same type
= note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits>
= note: for information on trait objects, see <https://doc.rust-lang.org/book/ch17-02-trait-objects.html#using-trait-objects-that-allow-for-values-of-different-types>
= help: alternatively, create a new `enum` with a variant for each returned type
= help: you could instead create a new `enum` with a variant for each returned type
help: you could change the return type to be a boxed trait object
|
LL | fn bat() -> Box<dyn std::fmt::Display> {
| ^^^^^^^ ^
help: if you change the return type to expect trait objects, box the returned expressions
|
LL | 0 => return Box::new(0i32),
LL | _ => Box::new(1u32),
|
error[E0308]: mismatched types
--> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:40:5
@ -120,11 +143,19 @@ LL | | }
= note: to return `impl Trait`, all returned values must be of the same type
= note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits>
= note: for information on trait objects, see <https://doc.rust-lang.org/book/ch17-02-trait-objects.html#using-trait-objects-that-allow-for-values-of-different-types>
= help: alternatively, create a new `enum` with a variant for each returned type
= help: you could instead create a new `enum` with a variant for each returned type
help: you could change the return type to be a boxed trait object
|
LL | fn can() -> Box<dyn std::fmt::Display> {
| ^^^^^^^ ^
help: if you change the return type to expect trait objects, box the returned expressions
|
LL | Box::new(match 13 {
LL | 0 => return Box::new(0i32),
LL | 1 => 1u32,
LL | _ => 2u32,
LL | })
|
error[E0308]: mismatched types
--> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:53:13
@ -141,11 +172,18 @@ LL | 1u32
= note: to return `impl Trait`, all returned values must be of the same type
= note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits>
= note: for information on trait objects, see <https://doc.rust-lang.org/book/ch17-02-trait-objects.html#using-trait-objects-that-allow-for-values-of-different-types>
= help: alternatively, create a new `enum` with a variant for each returned type
= help: you could instead create a new `enum` with a variant for each returned type
help: you could change the return type to be a boxed trait object
|
LL | fn cat() -> Box<dyn std::fmt::Display> {
| ^^^^^^^ ^
help: if you change the return type to expect trait objects, box the returned expressions
|
LL | return Box::new(0i32);
LL | }
LL | _ => {
LL | Box::new(1u32)
|
error[E0308]: `match` arms have incompatible types
--> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:61:14
@ -163,7 +201,7 @@ help: you could change the return type to be a boxed trait object
|
LL | fn dog() -> Box<dyn std::fmt::Display> {
| ^^^^^^^ ^
help: if you change the return type to expect trait objects box the returned expressions
help: if you change the return type to expect trait objects, box the returned expressions
|
LL | 0 => Box::new(0i32),
LL | 1 => Box::new(1u32),