Rollup merge of #67127 - estebank:disambiguate-suggestion, r=varkor

Use structured suggestion for disambiguating method calls

Fix #65635.
This commit is contained in:
Mazdak Farrokhzad 2019-12-20 12:17:20 +01:00 committed by GitHub
commit f0eb4b4752
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GPG Key ID: 4AEE18F83AFDEB23
18 changed files with 274 additions and 82 deletions

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@ -212,6 +212,17 @@ pub enum AssocKind {
Type
}
impl AssocKind {
pub fn suggestion_descr(&self) -> &'static str {
match self {
ty::AssocKind::Method => "method call",
ty::AssocKind::Type |
ty::AssocKind::OpaqueTy => "associated type",
ty::AssocKind::Const => "associated constant",
}
}
}
impl AssocItem {
pub fn def_kind(&self) -> DefKind {
match self.kind {

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@ -1425,8 +1425,7 @@ fn check_field(
field: ast::Ident,
) -> Ty<'tcx> {
let expr_t = self.check_expr_with_needs(base, needs);
let expr_t = self.structurally_resolved_type(base.span,
expr_t);
let expr_t = self.structurally_resolved_type(base.span, expr_t);
let mut private_candidate = None;
let mut autoderef = self.autoderef(expr.span, expr_t);
while let Some((base_t, _)) = autoderef.next() {

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@ -15,7 +15,7 @@
use rustc::ty::{self, Ty, TyCtxt, ToPolyTraitRef, ToPredicate, TypeFoldable};
use rustc::ty::print::with_crate_prefix;
use syntax_pos::{Span, FileName};
use syntax::ast;
use syntax::{ast, source_map};
use syntax::util::lev_distance;
use rustc_error_codes::*;
@ -79,37 +79,11 @@ pub fn report_method_error<'b>(
return None;
}
let print_disambiguation_help = |
err: &mut DiagnosticBuilder<'_>,
trait_name: String,
| {
err.help(&format!(
"to disambiguate the method call, write `{}::{}({}{})` instead",
trait_name,
item_name,
if rcvr_ty.is_region_ptr() && args.is_some() {
if rcvr_ty.is_mutable_ptr() {
"&mut "
} else {
"&"
}
} else {
""
},
args.map(|arg| arg
.iter()
.map(|arg| self.tcx.sess.source_map().span_to_snippet(arg.span)
.unwrap_or_else(|_| "...".to_owned()))
.collect::<Vec<_>>()
.join(", ")
).unwrap_or_else(|| "...".to_owned())
));
};
let report_candidates = |
span: Span,
err: &mut DiagnosticBuilder<'_>,
mut sources: Vec<CandidateSource>,
sugg_span: Span,
| {
sources.sort();
sources.dedup();
@ -150,15 +124,19 @@ pub fn report_method_error<'b>(
}
};
let note_str = if sources.len() > 1 {
format!("candidate #{} is defined in an impl{} for the type `{}`",
idx + 1,
insertion,
impl_ty)
let (note_str, idx) = if sources.len() > 1 {
(format!(
"candidate #{} is defined in an impl{} for the type `{}`",
idx + 1,
insertion,
impl_ty,
), Some(idx + 1))
} else {
format!("the candidate is defined in an impl{} for the type `{}`",
insertion,
impl_ty)
(format!(
"the candidate is defined in an impl{} for the type `{}`",
insertion,
impl_ty,
), None)
};
if let Some(note_span) = note_span {
// We have a span pointing to the method. Show note with snippet.
@ -168,7 +146,31 @@ pub fn report_method_error<'b>(
err.note(&note_str);
}
if let Some(trait_ref) = self.tcx.impl_trait_ref(impl_did) {
print_disambiguation_help(err, self.tcx.def_path_str(trait_ref.def_id));
let path = self.tcx.def_path_str(trait_ref.def_id);
let ty = match item.kind {
ty::AssocKind::Const |
ty::AssocKind::Type |
ty::AssocKind::OpaqueTy => rcvr_ty,
ty::AssocKind::Method => self.tcx.fn_sig(item.def_id)
.inputs()
.skip_binder()
.get(0)
.filter(|ty| ty.is_region_ptr() && !rcvr_ty.is_region_ptr())
.map(|ty| *ty)
.unwrap_or(rcvr_ty),
};
print_disambiguation_help(
item_name,
args,
err,
path,
ty,
item.kind,
sugg_span,
idx,
self.tcx.sess.source_map(),
);
}
}
CandidateSource::TraitSource(trait_did) => {
@ -182,19 +184,32 @@ pub fn report_method_error<'b>(
};
let item_span = self.tcx.sess.source_map()
.def_span(self.tcx.def_span(item.def_id));
if sources.len() > 1 {
let idx = if sources.len() > 1 {
span_note!(err,
item_span,
"candidate #{} is defined in the trait `{}`",
idx + 1,
self.tcx.def_path_str(trait_did));
Some(idx + 1)
} else {
span_note!(err,
item_span,
"the candidate is defined in the trait `{}`",
self.tcx.def_path_str(trait_did));
}
print_disambiguation_help(err, self.tcx.def_path_str(trait_did));
None
};
let path = self.tcx.def_path_str(trait_did);
print_disambiguation_help(
item_name,
args,
err,
path,
rcvr_ty,
item.kind,
sugg_span,
idx,
self.tcx.sess.source_map(),
);
}
}
}
@ -203,6 +218,13 @@ pub fn report_method_error<'b>(
}
};
let sugg_span = if let SelfSource::MethodCall(expr) = source {
// Given `foo.bar(baz)`, `expr` is `bar`, but we want to point to the whole thing.
self.tcx.hir().expect_expr(self.tcx.hir().get_parent_node(expr.hir_id)).span
} else {
span
};
match error {
MethodError::NoMatch(NoMatchData {
static_candidates: static_sources,
@ -495,9 +517,9 @@ macro_rules! report_function {
));
}
report_candidates(span, &mut err, static_sources);
report_candidates(span, &mut err, static_sources, sugg_span);
} else if static_sources.len() > 1 {
report_candidates(span, &mut err, static_sources);
report_candidates(span, &mut err, static_sources, sugg_span);
}
if !unsatisfied_predicates.is_empty() {
@ -584,7 +606,7 @@ macro_rules! report_function {
"multiple applicable items in scope");
err.span_label(span, format!("multiple `{}` found", item_name));
report_candidates(span, &mut err, sources);
report_candidates(span, &mut err, sources, sugg_span);
err.emit();
}
@ -1123,3 +1145,56 @@ fn nested_visit_map<'this>(
hir::intravisit::NestedVisitorMap::None
}
}
fn print_disambiguation_help(
item_name: ast::Ident,
args: Option<&'tcx [hir::Expr]>,
err: &mut DiagnosticBuilder<'_>,
trait_name: String,
rcvr_ty: Ty<'_>,
kind: ty::AssocKind,
span: Span,
candidate: Option<usize>,
source_map: &source_map::SourceMap,
) {
let mut applicability = Applicability::MachineApplicable;
let sugg_args = if let (ty::AssocKind::Method, Some(args)) = (kind, args) {
format!(
"({}{})",
if rcvr_ty.is_region_ptr() {
if rcvr_ty.is_mutable_ptr() {
"&mut "
} else {
"&"
}
} else {
""
},
args.iter()
.map(|arg| source_map.span_to_snippet(arg.span)
.unwrap_or_else(|_| {
applicability = Applicability::HasPlaceholders;
"_".to_owned()
}))
.collect::<Vec<_>>()
.join(", "),
)
} else {
String::new()
};
let sugg = format!("{}::{}{}", trait_name, item_name, sugg_args);
err.span_suggestion(
span,
&format!(
"disambiguate the {} for {}",
kind.suggestion_descr(),
if let Some(candidate) = candidate {
format!("candidate #{}", candidate)
} else {
"the candidate".to_string()
},
),
sugg,
applicability,
);
}

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@ -9,13 +9,19 @@ note: candidate #1 is defined in an impl of the trait `Foo` for the type `i32`
|
LL | const ID: i32 = 1;
| ^^^^^^^^^^^^^^^^^^
= help: to disambiguate the method call, write `Foo::ID(...)` instead
note: candidate #2 is defined in an impl of the trait `Bar` for the type `i32`
--> $DIR/associated-const-ambiguity-report.rs:14:5
|
LL | const ID: i32 = 3;
| ^^^^^^^^^^^^^^^^^^
= help: to disambiguate the method call, write `Bar::ID(...)` instead
help: disambiguate the associated constant for candidate #1
|
LL | const X: i32 = Foo::ID;
| ^^^^^^^
help: disambiguate the associated constant for candidate #2
|
LL | const X: i32 = Bar::ID;
| ^^^^^^^
error: aborting due to previous error

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@ -9,13 +9,19 @@ note: candidate #1 is defined in an impl of the trait `Trait1` for the type `Tes
|
LL | fn foo() {}
| ^^^^^^^^
= help: to disambiguate the method call, write `Trait1::foo(...)` instead
note: candidate #2 is defined in an impl of the trait `Trait2` for the type `Test`
--> $DIR/E0034.rs:16:5
|
LL | fn foo() {}
| ^^^^^^^^
= help: to disambiguate the method call, write `Trait2::foo(...)` instead
help: disambiguate the method call for candidate #1
|
LL | Trait1::foo()
| ^^^^^^^^^^^
help: disambiguate the method call for candidate #2
|
LL | Trait2::foo()
| ^^^^^^^^^^^
error: aborting due to previous error

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@ -5,9 +5,15 @@ LL | assert_eq!('x'.ipu_flatten(), 0);
| ^^^^^^^^^^^ multiple `ipu_flatten` found
|
= note: candidate #1 is defined in an impl of the trait `inference_unstable_iterator::IpuIterator` for the type `char`
= help: to disambiguate the method call, write `inference_unstable_iterator::IpuIterator::ipu_flatten('x')` instead
= note: candidate #2 is defined in an impl of the trait `inference_unstable_itertools::IpuItertools` for the type `char`
= help: to disambiguate the method call, write `inference_unstable_itertools::IpuItertools::ipu_flatten('x')` instead
help: disambiguate the method call for candidate #1
|
LL | assert_eq!(inference_unstable_iterator::IpuIterator::ipu_flatten(&'x'), 0);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: disambiguate the method call for candidate #2
|
LL | assert_eq!(inference_unstable_itertools::IpuItertools::ipu_flatten(&'x'), 0);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: aborting due to previous error

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@ -2,7 +2,10 @@ error[E0034]: multiple applicable items in scope
--> $DIR/issue-18446.rs:18:7
|
LL | x.foo();
| ^^^ multiple `foo` found
| --^^^--
| | |
| | multiple `foo` found
| help: disambiguate the method call for candidate #2: `T::foo(&x)`
|
note: candidate #1 is defined in an impl for the type `dyn T`
--> $DIR/issue-18446.rs:9:5
@ -14,7 +17,6 @@ note: candidate #2 is defined in the trait `T`
|
LL | fn foo(&self);
| ^^^^^^^^^^^^^^
= help: to disambiguate the method call, write `T::foo(&x)` instead
error: aborting due to previous error

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@ -9,13 +9,19 @@ note: candidate #1 is defined in an impl of the trait `ToPrimitive` for the type
|
LL | fn to_int(&self) -> isize { 0 }
| ^^^^^^^^^^^^^^^^^^^^^^^^^
= help: to disambiguate the method call, write `ToPrimitive::to_int(&self)` instead
note: candidate #2 is defined in an impl of the trait `Add` for the type `isize`
--> $DIR/issue-3702-2.rs:14:5
|
LL | fn to_int(&self) -> isize { *self }
| ^^^^^^^^^^^^^^^^^^^^^^^^^
= help: to disambiguate the method call, write `Add::to_int(&self)` instead
help: disambiguate the method call for candidate #1
|
LL | ToPrimitive::to_int(&self) + other.to_int()
| ^^^^^^^^^^^^^^^^^^^^^^^^^^
help: disambiguate the method call for candidate #2
|
LL | Add::to_int(&self) + other.to_int()
| ^^^^^^^^^^^^^^^^^^
error: aborting due to previous error

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@ -9,13 +9,19 @@ note: candidate #1 is defined in an impl of the trait `async` for the type `r#fn
|
LL | fn r#struct(&self) {
| ^^^^^^^^^^^^^^^^^^
= help: to disambiguate the method call, write `async::r#struct(r#fn {})` instead
note: candidate #2 is defined in an impl of the trait `await` for the type `r#fn`
--> $DIR/issue-65634-raw-ident-suggestion.rs:10:5
|
LL | fn r#struct(&self) {
| ^^^^^^^^^^^^^^^^^^
= help: to disambiguate the method call, write `await::r#struct(r#fn {})` instead
help: disambiguate the method call for candidate #1
|
LL | async::r#struct(&r#fn {});
| ^^^^^^^^^^^^^^^^^^^^^^^^^
help: disambiguate the method call for candidate #2
|
LL | await::r#struct(&r#fn {});
| ^^^^^^^^^^^^^^^^^^^^^^^^^
error: aborting due to previous error

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@ -9,9 +9,15 @@ note: candidate #1 is defined in an impl of the trait `Me2` for the type `usize`
|
LL | impl Me2 for usize { fn me(&self) -> usize { *self } }
| ^^^^^^^^^^^^^^^^^^^^^
= help: to disambiguate the method call, write `Me2::me(1_usize)` instead
= note: candidate #2 is defined in an impl of the trait `ambig_impl_2_lib::Me` for the type `usize`
= help: to disambiguate the method call, write `ambig_impl_2_lib::Me::me(1_usize)` instead
help: disambiguate the method call for candidate #1
|
LL | fn main() { Me2::me(&1_usize); }
| ^^^^^^^^^^^^^^^^^
help: disambiguate the method call for candidate #2
|
LL | fn main() { ambig_impl_2_lib::Me::me(&1_usize); }
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: aborting due to previous error

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@ -9,13 +9,19 @@ note: candidate #1 is defined in the trait `A`
|
LL | trait A { fn foo(&self); }
| ^^^^^^^^^^^^^^
= help: to disambiguate the method call, write `A::foo(t)` instead
note: candidate #2 is defined in the trait `B`
--> $DIR/method-ambig-two-traits-from-bounds.rs:2:11
|
LL | trait B { fn foo(&self); }
| ^^^^^^^^^^^^^^
= help: to disambiguate the method call, write `B::foo(t)` instead
help: disambiguate the method call for candidate #1
|
LL | A::foo(t);
| ^^^^^^^^^
help: disambiguate the method call for candidate #2
|
LL | B::foo(t);
| ^^^^^^^^^
error: aborting due to previous error

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@ -9,13 +9,19 @@ note: candidate #1 is defined in an impl of the trait `A` for the type `AB`
|
LL | fn foo(self) {}
| ^^^^^^^^^^^^
= help: to disambiguate the method call, write `A::foo(AB {})` instead
note: candidate #2 is defined in an impl of the trait `B` for the type `AB`
--> $DIR/method-ambig-two-traits-from-impls.rs:11:5
|
LL | fn foo(self) {}
| ^^^^^^^^^^^^
= help: to disambiguate the method call, write `B::foo(AB {})` instead
help: disambiguate the method call for candidate #1
|
LL | A::foo(AB {});
| ^^^^^^^^^^^^^
help: disambiguate the method call for candidate #2
|
LL | B::foo(AB {});
| ^^^^^^^^^^^^^
error: aborting due to previous error

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@ -9,13 +9,19 @@ note: candidate #1 is defined in an impl of the trait `A` for the type `AB`
|
LL | fn foo() {}
| ^^^^^^^^
= help: to disambiguate the method call, write `A::foo(...)` instead
note: candidate #2 is defined in an impl of the trait `B` for the type `AB`
--> $DIR/method-ambig-two-traits-from-impls2.rs:11:5
|
LL | fn foo() {}
| ^^^^^^^^
= help: to disambiguate the method call, write `B::foo(...)` instead
help: disambiguate the method call for candidate #1
|
LL | A::foo();
| ^^^^^^
help: disambiguate the method call for candidate #2
|
LL | B::foo();
| ^^^^^^
error: aborting due to previous error

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@ -9,13 +9,19 @@ note: candidate #1 is defined in an impl of the trait `Foo` for the type `usize`
|
LL | trait Foo { fn method(&self) {} }
| ^^^^^^^^^^^^^^^^
= help: to disambiguate the method call, write `Foo::method(1_usize)` instead
note: candidate #2 is defined in an impl of the trait `Bar` for the type `usize`
--> $DIR/method-ambig-two-traits-with-default-method.rs:6:13
|
LL | trait Bar { fn method(&self) {} }
| ^^^^^^^^^^^^^^^^
= help: to disambiguate the method call, write `Bar::method(1_usize)` instead
help: disambiguate the method call for candidate #1
|
LL | Foo::method(&1_usize);
| ^^^^^^^^^^^^^^^^^^^^^
help: disambiguate the method call for candidate #2
|
LL | Bar::method(&1_usize);
| ^^^^^^^^^^^^^^^^^^^^^
error: aborting due to previous error

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@ -25,19 +25,28 @@ note: candidate #1 is defined in an impl of the trait `internal::X` for the type
|
LL | fn foo(self: Smaht<Self, u64>) -> u64 {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
= help: to disambiguate the method call, write `internal::X::foo(x)` instead
note: candidate #2 is defined in an impl of the trait `nuisance_foo::NuisanceFoo` for the type `_`
--> $DIR/method-deref-to-same-trait-object-with-separate-params.rs:70:9
|
LL | fn foo(self) {}
| ^^^^^^^^^^^^
= help: to disambiguate the method call, write `nuisance_foo::NuisanceFoo::foo(x)` instead
note: candidate #3 is defined in the trait `FinalFoo`
--> $DIR/method-deref-to-same-trait-object-with-separate-params.rs:57:5
|
LL | fn foo(&self) -> u8;
| ^^^^^^^^^^^^^^^^^^^^
= help: to disambiguate the method call, write `FinalFoo::foo(x)` instead
help: disambiguate the method call for candidate #1
|
LL | let z = internal::X::foo(x);
| ^^^^^^^^^^^^^^^^^^^
help: disambiguate the method call for candidate #2
|
LL | let z = nuisance_foo::NuisanceFoo::foo(x);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: disambiguate the method call for candidate #3
|
LL | let z = FinalFoo::foo(x);
| ^^^^^^^^^^^^^^^^
error[E0308]: mismatched types
--> $DIR/method-deref-to-same-trait-object-with-separate-params.rs:137:24

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@ -9,13 +9,19 @@ note: candidate #1 is defined in the trait `A`
|
LL | fn foo(&mut self) {}
| ^^^^^^^^^^^^^^^^^
= help: to disambiguate the method call, write `A::foo(&a)` instead
note: candidate #2 is defined in the trait `B`
--> $DIR/issue-37767.rs:6:5
|
LL | fn foo(&mut self) {}
| ^^^^^^^^^^^^^^^^^
= help: to disambiguate the method call, write `B::foo(&a)` instead
help: disambiguate the method call for candidate #1
|
LL | A::foo(&a)
| ^^^^^^^^^^
help: disambiguate the method call for candidate #2
|
LL | B::foo(&a)
| ^^^^^^^^^^
error[E0034]: multiple applicable items in scope
--> $DIR/issue-37767.rs:22:7
@ -28,13 +34,19 @@ note: candidate #1 is defined in the trait `C`
|
LL | fn foo(&self) {}
| ^^^^^^^^^^^^^
= help: to disambiguate the method call, write `C::foo(&a)` instead
note: candidate #2 is defined in the trait `D`
--> $DIR/issue-37767.rs:18:5
|
LL | fn foo(&self) {}
| ^^^^^^^^^^^^^
= help: to disambiguate the method call, write `D::foo(&a)` instead
help: disambiguate the method call for candidate #1
|
LL | C::foo(&a)
| ^^^^^^^^^^
help: disambiguate the method call for candidate #2
|
LL | D::foo(&a)
| ^^^^^^^^^^
error[E0034]: multiple applicable items in scope
--> $DIR/issue-37767.rs:34:7
@ -47,13 +59,19 @@ note: candidate #1 is defined in the trait `E`
|
LL | fn foo(self) {}
| ^^^^^^^^^^^^
= help: to disambiguate the method call, write `E::foo(a)` instead
note: candidate #2 is defined in the trait `F`
--> $DIR/issue-37767.rs:30:5
|
LL | fn foo(self) {}
| ^^^^^^^^^^^^
= help: to disambiguate the method call, write `F::foo(a)` instead
help: disambiguate the method call for candidate #1
|
LL | E::foo(a)
| ^^^^^^^^^
help: disambiguate the method call for candidate #2
|
LL | F::foo(a)
| ^^^^^^^^^
error: aborting due to 3 previous errors

View File

@ -10,24 +10,33 @@ note: candidate #1 is defined in the trait `CtxtFn`
|
LL | fn f9(_: usize) -> usize;
| ^^^^^^^^^^^^^^^^^^^^^^^^^
= help: to disambiguate the method call, write `CtxtFn::f9(u, 342)` instead
note: candidate #2 is defined in the trait `OtherTrait`
--> $DIR/issue-7575.rs:8:5
|
LL | fn f9(_: usize) -> usize;
| ^^^^^^^^^^^^^^^^^^^^^^^^^
= help: to disambiguate the method call, write `OtherTrait::f9(u, 342)` instead
note: candidate #3 is defined in the trait `UnusedTrait`
--> $DIR/issue-7575.rs:17:5
|
LL | fn f9(_: usize) -> usize;
| ^^^^^^^^^^^^^^^^^^^^^^^^^
= help: to disambiguate the method call, write `UnusedTrait::f9(u, 342)` instead
= help: items from traits can only be used if the trait is implemented and in scope
= note: the following traits define an item `f9`, perhaps you need to implement one of them:
candidate #1: `CtxtFn`
candidate #2: `OtherTrait`
candidate #3: `UnusedTrait`
help: disambiguate the method call for candidate #1
|
LL | u.f8(42) + CtxtFn::f9(u, 342) + m.fff(42)
| ^^^^^^^^^^^^^^^^^^
help: disambiguate the method call for candidate #2
|
LL | u.f8(42) + OtherTrait::f9(u, 342) + m.fff(42)
| ^^^^^^^^^^^^^^^^^^^^^^
help: disambiguate the method call for candidate #3
|
LL | u.f8(42) + UnusedTrait::f9(u, 342) + m.fff(42)
| ^^^^^^^^^^^^^^^^^^^^^^^
error[E0599]: no method named `fff` found for type `Myisize` in the current scope
--> $DIR/issue-7575.rs:62:30
@ -60,8 +69,11 @@ note: the candidate is defined in the trait `ManyImplTrait`
|
LL | fn is_str() -> bool {
| ^^^^^^^^^^^^^^^^^^^
= help: to disambiguate the method call, write `ManyImplTrait::is_str(t)` instead
= help: items from traits can only be used if the type parameter is bounded by the trait
help: disambiguate the method call for the candidate
|
LL | ManyImplTrait::is_str(t)
|
help: the following trait defines an item `is_str`, perhaps you need to restrict type parameter `T` with it:
|
LL | fn param_bound<T: ManyImplTrait + ManyImplTrait>(t: T) -> bool {

View File

@ -9,13 +9,19 @@ note: candidate #1 is defined in an impl of the trait `inner::A` for the type `u
|
LL | fn foo(&self) {}
| ^^^^^^^^^^^^^
= help: to disambiguate the method call, write `inner::A::foo(t)` instead
note: candidate #2 is defined in an impl of the trait `inner::B` for the type `u8`
--> $DIR/trait-alias-ambiguous.rs:11:9
|
LL | fn foo(&self) {}
| ^^^^^^^^^^^^^
= help: to disambiguate the method call, write `inner::B::foo(t)` instead
help: disambiguate the method call for candidate #1
|
LL | inner::A::foo(&t);
| ^^^^^^^^^^^^^^^^^
help: disambiguate the method call for candidate #2
|
LL | inner::B::foo(&t);
| ^^^^^^^^^^^^^^^^^
error: aborting due to previous error