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Rework borrowing suggestions to use Expr instead of just Span

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In the suggestion machinery for borrowing expressions and types, always use the available obligation `Span` to find the appropriate `Expr` to perform appropriateness checks no the `ExprKind` instead of on the textual snippet corresponding to the `Span`.

Unify the logic for the case where `&` *and* `&mut` are appropriate with the logic for only one of those cases.

Handle the case when `S::foo()` should have been `<&S>::foo()` (instead of suggesting the prior `&S::foo()`.
This commit is contained in:
Esteban Küber 2025-07-10 17:15:42 +00:00
parent 78a6e13298
commit 7dfc3e9af4
16 changed files with 217 additions and 213 deletions
Download patch file Download diff file Expand all files Collapse all files

228
compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
View file

@ -1321,7 +1321,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
let imm_ref_self_ty_satisfies_pred = mk_result(trait_pred_and_imm_ref);
let mut_ref_self_ty_satisfies_pred = mk_result(trait_pred_and_mut_ref);
let (ref_inner_ty_satisfies_pred, ref_inner_ty_mut) =
let (ref_inner_ty_satisfies_pred, ref_inner_ty_is_mut) =
if let ObligationCauseCode::WhereClauseInExpr(..) = obligation.cause.code()
&& let ty::Ref(_, ty, mutability) = old_pred.self_ty().skip_binder().kind()
{
@ -1333,117 +1333,139 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
(false, false)
};
if imm_ref_self_ty_satisfies_pred
|| mut_ref_self_ty_satisfies_pred
|| ref_inner_ty_satisfies_pred
{
if let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(span) {
// We don't want a borrowing suggestion on the fields in structs,
// ```
// struct Foo {
// the_foos: Vec<Foo>
// }
// ```
if !matches!(
span.ctxt().outer_expn_data().kind,
ExpnKind::Root | ExpnKind::Desugaring(DesugaringKind::ForLoop)
) {
return false;
}
if snippet.starts_with('&') {
// This is already a literal borrow and the obligation is failing
// somewhere else in the obligation chain. Do not suggest non-sense.
return false;
}
// We have a very specific type of error, where just borrowing this argument
// might solve the problem. In cases like this, the important part is the
// original type obligation, not the last one that failed, which is arbitrary.
// Because of this, we modify the error to refer to the original obligation and
// return early in the caller.
let is_immut = imm_ref_self_ty_satisfies_pred
|| (ref_inner_ty_satisfies_pred && !ref_inner_ty_is_mut);
let is_mut = mut_ref_self_ty_satisfies_pred || ref_inner_ty_is_mut;
if !is_immut && !is_mut {
return false;
}
let Ok(_snippet) = self.tcx.sess.source_map().span_to_snippet(span) else {
return false;
};
// We don't want a borrowing suggestion on the fields in structs
// ```
// #[derive(Clone)]
// struct Foo {
// the_foos: Vec<Foo>
// }
// ```
if !matches!(
span.ctxt().outer_expn_data().kind,
ExpnKind::Root | ExpnKind::Desugaring(DesugaringKind::ForLoop)
) {
return false;
}
// We have a very specific type of error, where just borrowing this argument
// might solve the problem. In cases like this, the important part is the
// original type obligation, not the last one that failed, which is arbitrary.
// Because of this, we modify the error to refer to the original obligation and
// return early in the caller.
let msg = format!(
"the trait bound `{}` is not satisfied",
self.tcx.short_string(old_pred, err.long_ty_path()),
);
let self_ty_str =
self.tcx.short_string(old_pred.self_ty().skip_binder(), err.long_ty_path());
if has_custom_message {
err.note(msg);
} else {
err.messages = vec![(rustc_errors::DiagMessage::from(msg), Style::NoStyle)];
}
err.span_label(
span,
format!(
"the trait `{}` is not implemented for `{self_ty_str}`",
old_pred.print_modifiers_and_trait_path()
),
);
let mut label = || {
let msg = format!(
"the trait bound `{}` is not satisfied",
self.tcx.short_string(old_pred, err.long_ty_path()),
);
let self_ty_str =
self.tcx.short_string(old_pred.self_ty().skip_binder(), err.long_ty_path());
if has_custom_message {
err.note(msg);
} else {
err.messages = vec![(rustc_errors::DiagMessage::from(msg), Style::NoStyle)];
}
err.span_label(
span,
format!(
"the trait `{}` is not implemented for `{self_ty_str}`",
old_pred.print_modifiers_and_trait_path()
),
);
};
if imm_ref_self_ty_satisfies_pred && mut_ref_self_ty_satisfies_pred {
err.span_suggestions(
span.shrink_to_lo(),
"consider borrowing here",
["&".to_string(), "&mut ".to_string()],
Applicability::MaybeIncorrect,
);
} else {
let is_mut = mut_ref_self_ty_satisfies_pred || ref_inner_ty_mut;
let sugg_prefix = format!("&{}", if is_mut { "mut " } else { "" });
let sugg_msg = format!(
"consider{} borrowing here",
if is_mut { " mutably" } else { "" }
);
let mut sugg_prefixes = vec![];
if is_immut {
sugg_prefixes.push("&");
}
if is_mut {
sugg_prefixes.push("&mut ");
}
let sugg_msg = format!(
"consider{} borrowing here",
if is_mut && !is_immut { " mutably" } else { "" },
);
// Issue #109436, we need to add parentheses properly for method calls
// for example, `foo.into()` should be `(&foo).into()`
if let Some(_) =
self.tcx.sess.source_map().span_look_ahead(span, ".", Some(50))
{
err.multipart_suggestion_verbose(
sugg_msg,
vec![
(span.shrink_to_lo(), format!("({sugg_prefix}")),
(span.shrink_to_hi(), ")".to_string()),
],
Applicability::MaybeIncorrect,
);
return true;
}
// Issue #104961, we need to add parentheses properly for compound expressions
// for example, `x.starts_with("hi".to_string() + "you")`
// should be `x.starts_with(&("hi".to_string() + "you"))`
let Some(body) = self.tcx.hir_maybe_body_owned_by(obligation.cause.body_id) else {
return false;
};
let mut expr_finder = FindExprBySpan::new(span, self.tcx);
expr_finder.visit_expr(body.value);
// Issue #104961, we need to add parentheses properly for compound expressions
// for example, `x.starts_with("hi".to_string() + "you")`
// should be `x.starts_with(&("hi".to_string() + "you"))`
let Some(body) = self.tcx.hir_maybe_body_owned_by(obligation.cause.body_id)
else {
return false;
};
let mut expr_finder = FindExprBySpan::new(span, self.tcx);
expr_finder.visit_expr(body.value);
let Some(expr) = expr_finder.result else {
return false;
};
let needs_parens = expr_needs_parens(expr);
let span = if needs_parens { span } else { span.shrink_to_lo() };
let suggestions = if !needs_parens {
vec![(span.shrink_to_lo(), sugg_prefix)]
} else {
if let Some(ty) = expr_finder.ty_result {
if let hir::Node::Expr(expr) = self.tcx.parent_hir_node(ty.hir_id)
&& let hir::ExprKind::Path(hir::QPath::TypeRelative(_, _)) = expr.kind
&& ty.span == span
{
// We've encountered something like `str::from("")`, where the intended code
// was likely `<&str>::from("")`. #143393.
label();
err.multipart_suggestions(
sugg_msg,
sugg_prefixes.into_iter().map(|sugg_prefix| {
vec![
(span.shrink_to_lo(), format!("{sugg_prefix}(")),
(span.shrink_to_hi(), ")".to_string()),
(span.shrink_to_lo(), format!("<{sugg_prefix}")),
(span.shrink_to_hi(), ">".to_string()),
]
};
err.multipart_suggestion_verbose(
sugg_msg,
suggestions,
Applicability::MaybeIncorrect,
);
}
}),
Applicability::MaybeIncorrect,
);
return true;
}
return false;
}
return false;
let Some(expr) = expr_finder.result else {
return false;
};
if let hir::ExprKind::AddrOf(_, _, _) = expr.kind {
return false;
}
let needs_parens_post = expr_needs_parens(expr);
let needs_parens_pre = match self.tcx.parent_hir_node(expr.hir_id) {
Node::Expr(e)
if let hir::ExprKind::MethodCall(_, base, _, _) = e.kind
&& base.hir_id == expr.hir_id =>
{
true
}
_ => false,
};
label();
let suggestions = sugg_prefixes.into_iter().map(|sugg_prefix| {
match (needs_parens_pre, needs_parens_post) {
(false, false) => vec![(span.shrink_to_lo(), sugg_prefix.to_string())],
// We have something like `foo.bar()`, where we want to bororw foo, so we need
// to suggest `(&mut foo).bar()`.
(false, true) => vec![
(span.shrink_to_lo(), format!("{sugg_prefix}(")),
(span.shrink_to_hi(), ")".to_string()),
],
// Issue #109436, we need to add parentheses properly for method calls
// for example, `foo.into()` should be `(&foo).into()`
(true, false) => vec![
(span.shrink_to_lo(), format!("({sugg_prefix}")),
(span.shrink_to_hi(), ")".to_string()),
],
(true, true) => vec![
(span.shrink_to_lo(), format!("({sugg_prefix}(")),
(span.shrink_to_hi(), "))".to_string()),
],
}
});
err.multipart_suggestions(sugg_msg, suggestions, Applicability::MaybeIncorrect);
return true;
};
if let ObligationCauseCode::ImplDerived(cause) = &*code {

20
tests/ui/consts/const-size_of_val-align_of_val-extern-type.stderr
View file

@ -2,25 +2,37 @@ error[E0277]: the size for values of type `Opaque` cannot be known
--> $DIR/const-size_of_val-align_of_val-extern-type.rs:10:43
|
LL | const _SIZE: usize = unsafe { size_of_val(&4 as *const i32 as *const Opaque) };
| ----------- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a known size
| ----------- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `MetaSized` is not implemented for `Opaque`
| |
| required by a bound introduced by this call
|
= help: the trait `MetaSized` is not implemented for `Opaque`
= note: the trait bound `Opaque: MetaSized` is not satisfied
note: required by a bound in `std::intrinsics::size_of_val`
--> $SRC_DIR/core/src/intrinsics/mod.rs:LL:COL
help: consider borrowing here
|
LL | const _SIZE: usize = unsafe { size_of_val(&(&4 as *const i32 as *const Opaque)) };
| ++ +
LL | const _SIZE: usize = unsafe { size_of_val(&mut (&4 as *const i32 as *const Opaque)) };
| ++++++ +
error[E0277]: the size for values of type `Opaque` cannot be known
--> $DIR/const-size_of_val-align_of_val-extern-type.rs:12:45
|
LL | const _ALIGN: usize = unsafe { align_of_val(&4 as *const i32 as *const Opaque) };
| ------------ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a known size
| ------------ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `MetaSized` is not implemented for `Opaque`
| |
| required by a bound introduced by this call
|
= help: the trait `MetaSized` is not implemented for `Opaque`
= note: the trait bound `Opaque: MetaSized` is not satisfied
note: required by a bound in `std::intrinsics::align_of_val`
--> $SRC_DIR/core/src/intrinsics/mod.rs:LL:COL
help: consider borrowing here
|
LL | const _ALIGN: usize = unsafe { align_of_val(&(&4 as *const i32 as *const Opaque)) };
| ++ +
LL | const _ALIGN: usize = unsafe { align_of_val(&mut (&4 as *const i32 as *const Opaque)) };
| ++++++ +
error: aborting due to 2 previous errors

30
tests/ui/derives/deriving-copyclone.stderr
View file

@ -2,8 +2,10 @@ error[E0277]: the trait bound `B<C>: Copy` is not satisfied
--> $DIR/deriving-copyclone.rs:31:26
|
LL | is_copy(B { a: 1, b: C });
| ------- ^ the trait `Copy` is not implemented for `B<C>`
| |
| ------- ^
| | |
| | the trait `Copy` is not implemented for `B<C>`
| | help: consider borrowing here: `&`
| required by a bound introduced by this call
|
note: required for `B<C>` to implement `Copy`
@ -16,17 +18,15 @@ note: required by a bound in `is_copy`
|
LL | fn is_copy<T: Copy>(_: T) {}
| ^^^^ required by this bound in `is_copy`
help: consider borrowing here
|
LL | is_copy(B { a: 1, b: &C });
| +
error[E0277]: the trait bound `B<C>: Clone` is not satisfied
--> $DIR/deriving-copyclone.rs:32:27
|
LL | is_clone(B { a: 1, b: C });
| -------- ^ the trait `Clone` is not implemented for `B<C>`
| |
| -------- ^
| | |
| | the trait `Clone` is not implemented for `B<C>`
| | help: consider borrowing here: `&`
| required by a bound introduced by this call
|
note: required for `B<C>` to implement `Clone`
@ -39,17 +39,15 @@ note: required by a bound in `is_clone`
|
LL | fn is_clone<T: Clone>(_: T) {}
| ^^^^^ required by this bound in `is_clone`
help: consider borrowing here
|
LL | is_clone(B { a: 1, b: &C });
| +
error[E0277]: the trait bound `B<D>: Copy` is not satisfied
--> $DIR/deriving-copyclone.rs:35:26
|
LL | is_copy(B { a: 1, b: D });
| ------- ^ the trait `Copy` is not implemented for `B<D>`
| |
| ------- ^
| | |
| | the trait `Copy` is not implemented for `B<D>`
| | help: consider borrowing here: `&`
| required by a bound introduced by this call
|
note: required for `B<D>` to implement `Copy`
@ -62,10 +60,6 @@ note: required by a bound in `is_copy`
|
LL | fn is_copy<T: Copy>(_: T) {}
| ^^^^ required by this bound in `is_copy`
help: consider borrowing here
|
LL | is_copy(B { a: 1, b: &D });
| +
error: aborting due to 3 previous errors

8
tests/ui/extern/unsized-extern-derefmove.stderr vendored
View file

@ -21,10 +21,10 @@ note: required by a bound in `Box::<T>::from_raw`
--> $SRC_DIR/alloc/src/boxed.rs:LL:COL
help: consider borrowing here
|
LL | Box::from_raw(&0 as *mut _)
| +
LL | Box::from_raw(&mut 0 as *mut _)
| ++++
LL | Box::from_raw(&(0 as *mut _))
| ++ +
LL | Box::from_raw(&mut (0 as *mut _))
| ++++++ +
error[E0277]: the size for values of type `Device` cannot be known
--> $DIR/unsized-extern-derefmove.rs:11:5

9
tests/ui/for/issue-20605.current.stderr
View file

@ -2,14 +2,13 @@ error[E0277]: `dyn Iterator<Item = &'a mut u8>` is not an iterator
--> $DIR/issue-20605.rs:6:17
|
LL | for item in *things { *item = 0 }
| ^^^^^^^ the trait `IntoIterator` is not implemented for `dyn Iterator<Item = &'a mut u8>`
| -^^^^^^
| |
| the trait `IntoIterator` is not implemented for `dyn Iterator<Item = &'a mut u8>`
| help: consider mutably borrowing here: `&mut`
|
= note: the trait bound `dyn Iterator<Item = &'a mut u8>: IntoIterator` is not satisfied
= note: required for `dyn Iterator<Item = &'a mut u8>` to implement `IntoIterator`
help: consider mutably borrowing here
|
LL | for item in &mut *things { *item = 0 }
| ++++
error: aborting due to 1 previous error

9
tests/ui/for/issue-20605.next.stderr
View file

@ -2,14 +2,13 @@ error[E0277]: `dyn Iterator<Item = &'a mut u8>` is not an iterator
--> $DIR/issue-20605.rs:6:17
|
LL | for item in *things { *item = 0 }
| ^^^^^^^ the trait `IntoIterator` is not implemented for `dyn Iterator<Item = &'a mut u8>`
| -^^^^^^
| |
| the trait `IntoIterator` is not implemented for `dyn Iterator<Item = &'a mut u8>`
| help: consider mutably borrowing here: `&mut`
|
= note: the trait bound `dyn Iterator<Item = &'a mut u8>: IntoIterator` is not satisfied
= note: required for `dyn Iterator<Item = &'a mut u8>` to implement `IntoIterator`
help: consider mutably borrowing here
|
LL | for item in &mut *things { *item = 0 }
| ++++
error: aborting due to 1 previous error

16
tests/ui/self/arbitrary_self_types_generic_over_receiver.stderr
View file

@ -30,10 +30,10 @@ LL | fn a(self: impl Receiver<Target=Self>) -> u32 {
| ^^^^^^^^^^^^^^^^^^^^^ required by this bound in `Foo::a`
help: consider borrowing here
|
LL | &foo.a();
| +
LL | &mut foo.a();
| ++++
LL | (&foo).a();
| ++ +
LL | (&mut foo).a();
| +++++ +
error[E0277]: the trait bound `Foo: Deref` is not satisfied
--> $DIR/arbitrary_self_types_generic_over_receiver.rs:21:9
@ -48,10 +48,10 @@ LL | fn b(self: impl Deref<Target=Self>) -> u32 {
| ^^^^^^^^^^^^^^^^^^ required by this bound in `Foo::b`
help: consider borrowing here
|
LL | &foo.b();
| +
LL | &mut foo.b();
| ++++
LL | (&foo).b();
| ++ +
LL | (&mut foo).b();
| +++++ +
error: aborting due to 4 previous errors

10
tests/ui/suggestions/imm-ref-trait-object-literal.stderr
View file

@ -21,8 +21,10 @@ error[E0277]: the trait bound `S: Trait` is not satisfied
--> $DIR/imm-ref-trait-object-literal.rs:13:7
|
LL | foo(s);
| --- ^ the trait `Trait` is not implemented for `S`
| |
| --- ^
| | |
| | the trait `Trait` is not implemented for `S`
| | help: consider mutably borrowing here: `&mut`
| required by a bound introduced by this call
|
note: required by a bound in `foo`
@ -30,10 +32,6 @@ note: required by a bound in `foo`
|
LL | fn foo<X: Trait>(_: X) {}
| ^^^^^ required by this bound in `foo`
help: consider mutably borrowing here
|
LL | foo(&mut s);
| ++++
error: aborting due to 2 previous errors

10
tests/ui/suggestions/issue-104961.stderr
View file

@ -18,17 +18,15 @@ error[E0277]: the trait bound `String: Pattern` is not satisfied
--> $DIR/issue-104961.rs:9:19
|
LL | x.starts_with("hi".to_string())
| ----------- ^^^^^^^^^^^^^^^^ the trait `Pattern` is not implemented for `String`
| |
| ----------- -^^^^^^^^^^^^^^^
| | |
| | the trait `Pattern` is not implemented for `String`
| | help: consider borrowing here: `&`
| required by a bound introduced by this call
|
= note: required for `String` to implement `Pattern`
note: required by a bound in `core::str::<impl str>::starts_with`
--> $SRC_DIR/core/src/str/mod.rs:LL:COL
help: consider borrowing here
|
LL | x.starts_with(&"hi".to_string())
| +
error: aborting due to 2 previous errors

10
tests/ui/suggestions/issue-62843.stderr
View file

@ -2,17 +2,15 @@ error[E0277]: the trait bound `String: Pattern` is not satisfied
--> $DIR/issue-62843.rs:4:32
|
LL | println!("{:?}", line.find(pattern));
| ---- ^^^^^^^ the trait `Pattern` is not implemented for `String`
| |
| ---- -^^^^^^
| | |
| | the trait `Pattern` is not implemented for `String`
| | help: consider borrowing here: `&`
| required by a bound introduced by this call
|
= note: required for `String` to implement `Pattern`
note: required by a bound in `core::str::<impl str>::find`
--> $SRC_DIR/core/src/str/mod.rs:LL:COL
help: consider borrowing here
|
LL | println!("{:?}", line.find(&pattern));
| +
error: aborting due to 1 previous error

10
tests/ui/suggestions/issue-84973-2.stderr
View file

@ -2,8 +2,10 @@ error[E0277]: the trait bound `i32: Tr` is not satisfied
--> $DIR/issue-84973-2.rs:11:9
|
LL | foo(a);
| --- ^ the trait `Tr` is not implemented for `i32`
| |
| --- ^
| | |
| | the trait `Tr` is not implemented for `i32`
| | help: consider mutably borrowing here: `&mut`
| required by a bound introduced by this call
|
note: required by a bound in `foo`
@ -11,10 +13,6 @@ note: required by a bound in `foo`
|
LL | fn foo<T: Tr>(i: T) {}
| ^^ required by this bound in `foo`
help: consider mutably borrowing here
|
LL | foo(&mut a);
| ++++
error: aborting due to 1 previous error

10
tests/ui/suggestions/issue-84973-negative.stderr
View file

@ -17,8 +17,10 @@ error[E0277]: the trait bound `f32: Tr` is not satisfied
--> $DIR/issue-84973-negative.rs:11:9
|
LL | bar(b);
| --- ^ the trait `Tr` is not implemented for `f32`
| |
| --- ^
| | |
| | the trait `Tr` is not implemented for `f32`
| | help: consider borrowing here: `&`
| required by a bound introduced by this call
|
note: required by a bound in `bar`
@ -26,10 +28,6 @@ note: required by a bound in `bar`
|
LL | fn bar<T: Tr>(t: T) {}
| ^^ required by this bound in `bar`
help: consider borrowing here
|
LL | bar(&b);
| +
error: aborting due to 2 previous errors

10
tests/ui/suggestions/issue-84973.stderr
View file

@ -2,8 +2,10 @@ error[E0277]: the trait bound `Fancy: SomeTrait` is not satisfied
--> $DIR/issue-84973.rs:6:24
|
LL | let o = Other::new(f);
| ---------- ^ the trait `SomeTrait` is not implemented for `Fancy`
| |
| ---------- ^
| | |
| | the trait `SomeTrait` is not implemented for `Fancy`
| | help: consider borrowing here: `&`
| required by a bound introduced by this call
|
note: required by a bound in `Other::<'a, G>::new`
@ -14,10 +16,6 @@ LL | G: SomeTrait,
LL | {
LL | pub fn new(g: G) -> Self {
| --- required by a bound in this associated function
help: consider borrowing here
|
LL | let o = Other::new(&f);
| +
error: aborting due to 1 previous error

20
tests/ui/suggestions/suggest-adding-reference-to-trait-assoc-item.stderr
View file

@ -2,23 +2,19 @@ error[E0277]: the trait bound `&mut usize: Default` is not satisfied
--> $DIR/suggest-adding-reference-to-trait-assoc-item.rs:13:9
|
LL | foo(Default::default());
| ^^^^^^^^^^^^^^^^^^ the trait `Default` is not implemented for `&mut usize`
|
help: consider mutably borrowing here
|
LL | foo(&mut Default::default());
| ++++
| -^^^^^^^^^^^^^^^^^
| |
| the trait `Default` is not implemented for `&mut usize`
| help: consider mutably borrowing here: `&mut`
error[E0277]: the trait bound `&usize: Default` is not satisfied
--> $DIR/suggest-adding-reference-to-trait-assoc-item.rs:14:9
|
LL | bar(Default::default());
| ^^^^^^^^^^^^^^^^^^ the trait `Default` is not implemented for `&usize`
|
help: consider borrowing here
|
LL | bar(&Default::default());
| +
| -^^^^^^^^^^^^^^^^^
| |
| the trait `Default` is not implemented for `&usize`
| help: consider borrowing here: `&`
error: aborting due to 2 previous errors

20
tests/ui/suggestions/suggest-imm-mut-trait-implementations.stderr
View file

@ -22,8 +22,10 @@ error[E0277]: the trait bound `B: Trait` is not satisfied
--> $DIR/suggest-imm-mut-trait-implementations.rs:21:9
|
LL | foo(b);
| --- ^ the trait `Trait` is not implemented for `B`
| |
| --- ^
| | |
| | the trait `Trait` is not implemented for `B`
| | help: consider borrowing here: `&`
| required by a bound introduced by this call
|
note: required by a bound in `foo`
@ -31,17 +33,15 @@ note: required by a bound in `foo`
|
LL | fn foo<X: Trait>(_: X) {}
| ^^^^^ required by this bound in `foo`
help: consider borrowing here
|
LL | foo(&b);
| +
error[E0277]: the trait bound `C: Trait` is not satisfied
--> $DIR/suggest-imm-mut-trait-implementations.rs:22:9
|
LL | foo(c);
| --- ^ the trait `Trait` is not implemented for `C`
| |
| --- ^
| | |
| | the trait `Trait` is not implemented for `C`
| | help: consider mutably borrowing here: `&mut`
| required by a bound introduced by this call
|
note: required by a bound in `foo`
@ -49,10 +49,6 @@ note: required by a bound in `foo`
|
LL | fn foo<X: Trait>(_: X) {}
| ^^^^^ required by this bound in `foo`
help: consider mutably borrowing here
|
LL | foo(&mut c);
| ++++
error: aborting due to 3 previous errors

10
tests/ui/traits/negative-impls/negated-auto-traits-error.stderr
View file

@ -61,8 +61,10 @@ error[E0277]: `dummy2::TestType` cannot be sent between threads safely
--> $DIR/negated-auto-traits-error.rs:48:13
|
LL | is_send(Box::new(TestType));
| ------- ^^^^^^^^^^^^^^^^^^ the trait `Send` is not implemented for `Unique<dummy2::TestType>`
| |
| ------- -^^^^^^^^^^^^^^^^^
| | |
| | the trait `Send` is not implemented for `Unique<dummy2::TestType>`
| | help: consider borrowing here: `&`
| required by a bound introduced by this call
|
= note: the trait bound `Unique<dummy2::TestType>: Send` is not satisfied
@ -74,10 +76,6 @@ note: required by a bound in `is_send`
|
LL | fn is_send<T: Send>(_: T) {}
| ^^^^ required by this bound in `is_send`
help: consider borrowing here
|
LL | is_send(&Box::new(TestType));
| +
error[E0277]: `dummy3::TestType` cannot be sent between threads safely
--> $DIR/negated-auto-traits-error.rs:56:13