diff options
6 files changed, 28 insertions, 16 deletions
diff --git a/compiler/rustc_typeck/src/check/fn_ctxt/suggestions.rs b/compiler/rustc_typeck/src/check/fn_ctxt/suggestions.rs index 37014b5eea5..e6a98ad6dc0 100644 --- a/compiler/rustc_typeck/src/check/fn_ctxt/suggestions.rs +++ b/compiler/rustc_typeck/src/check/fn_ctxt/suggestions.rs @@ -530,13 +530,20 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { err.span_suggestion( span, "try adding a return type", - format!("-> {} ", self.resolve_vars_with_obligations(found)), + format!("-> {} ", found), Applicability::MachineApplicable, ); true } (&hir::FnRetTy::DefaultReturn(span), false, true, true) => { - err.span_label(span, "possibly return type missing here?"); + // FIXME: if `found` could be `impl Iterator` or `impl Fn*`, we should suggest + // that. + err.span_suggestion( + span, + "a return type might be missing here", + "-> _ ".to_string(), + Applicability::HasPlaceholders, + ); true } (&hir::FnRetTy::DefaultReturn(span), _, false, true) => { diff --git a/src/test/ui/block-result/issue-20862.stderr b/src/test/ui/block-result/issue-20862.stderr index 09c06e8428d..e9ca0ad9029 100644 --- a/src/test/ui/block-result/issue-20862.stderr +++ b/src/test/ui/block-result/issue-20862.stderr @@ -2,7 +2,7 @@ error[E0308]: mismatched types --> $DIR/issue-20862.rs:2:5 | LL | fn foo(x: i32) { - | - possibly return type missing here? + | - help: a return type might be missing here: `-> _` LL | |y| x + y | ^^^^^^^^^ expected `()`, found closure | diff --git a/src/test/ui/never_type/diverging-tuple-parts-39485.stderr b/src/test/ui/never_type/diverging-tuple-parts-39485.stderr index e99a38aaaee..4b5b8c45d59 100644 --- a/src/test/ui/never_type/diverging-tuple-parts-39485.stderr +++ b/src/test/ui/never_type/diverging-tuple-parts-39485.stderr @@ -1,13 +1,15 @@ error[E0308]: mismatched types --> $DIR/diverging-tuple-parts-39485.rs:8:5 | -LL | fn g() { - | - possibly return type missing here? LL | &panic!() | ^^^^^^^^^ expected `()`, found reference | = note: expected unit type `()` found reference `&_` +help: a return type might be missing here + | +LL | fn g() -> _ { + | ++++ help: consider removing the borrow | LL - &panic!() diff --git a/src/test/ui/typeck/issue-91334.stderr b/src/test/ui/typeck/issue-91334.stderr index 0872e83ea2e..633c7b11aa2 100644 --- a/src/test/ui/typeck/issue-91334.stderr +++ b/src/test/ui/typeck/issue-91334.stderr @@ -40,7 +40,7 @@ error[E0308]: mismatched types LL | fn f(){||yield(((){), | -^^^^^^^^^^^^^^^ expected `()`, found generator | | - | possibly return type missing here? + | help: a return type might be missing here: `-> _` | = note: expected unit type `()` found generator `[generator@$DIR/issue-91334.rs:10:8: 10:23]` diff --git a/src/test/ui/typeck/return_type_containing_closure.rs b/src/test/ui/typeck/return_type_containing_closure.rs index aee9769b280..29624e08a2e 100644 --- a/src/test/ui/typeck/return_type_containing_closure.rs +++ b/src/test/ui/typeck/return_type_containing_closure.rs @@ -1,10 +1,10 @@ #[allow(unused)] -fn foo() { - //~^ NOTE possibly return type missing here? +fn foo() { //~ HELP a return type might be missing here vec!['a'].iter().map(|c| c) //~^ ERROR mismatched types [E0308] //~| NOTE expected `()`, found struct `Map` //~| NOTE expected unit type `()` + //~| HELP consider using a semicolon here } fn main() {} diff --git a/src/test/ui/typeck/return_type_containing_closure.stderr b/src/test/ui/typeck/return_type_containing_closure.stderr index b08152d6331..ae72b1477c8 100644 --- a/src/test/ui/typeck/return_type_containing_closure.stderr +++ b/src/test/ui/typeck/return_type_containing_closure.stderr @@ -1,16 +1,19 @@ error[E0308]: mismatched types - --> $DIR/return_type_containing_closure.rs:4:5 + --> $DIR/return_type_containing_closure.rs:3:5 | -LL | fn foo() { - | - possibly return type missing here? -LL | LL | vec!['a'].iter().map(|c| c) - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^- help: consider using a semicolon here: `;` - | | - | expected `()`, found struct `Map` + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `()`, found struct `Map` | = note: expected unit type `()` - found struct `Map<std::slice::Iter<'_, char>, [closure@$DIR/return_type_containing_closure.rs:4:26: 4:31]>` + found struct `Map<std::slice::Iter<'_, char>, [closure@$DIR/return_type_containing_closure.rs:3:26: 3:31]>` +help: consider using a semicolon here + | +LL | vec!['a'].iter().map(|c| c); + | + +help: a return type might be missing here + | +LL | fn foo() -> _ { + | ++++ error: aborting due to previous error |