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On type mismatch involving associated type, suggest constraint

Browse source 
When an associated type is found when a specific type was expected, if
possible provide a structured suggestion constraining the associated
type in a bound.

```
error[E0271]: type mismatch resolving `<T as Foo>::Y == i32`
  --> $DIR/associated-types-multiple-types-one-trait.rs:13:5
   |
LL |     want_y(t);
   |     ^^^^^^ expected `i32`, found associated type
...
LL | fn want_y<T:Foo<Y=i32>>(t: &T) { }
   |                 ----- required by this bound in `want_y`
   |
   = note:         expected type `i32`
           found associated type `<T as Foo>::Y`
help: consider constraining the associated type `<T as Foo>::Y` to `i32`
   |
LL | fn have_x_want_y<T:Foo<X=u32, Y = i32>>(t: &T)
   |                             ^^^^^^^^^
```

```
error[E0308]: mismatched types
  --> $DIR/trait-with-missing-associated-type-restriction.rs:12:9
   |
LL |     qux(x.func())
   |         ^^^^^^^^ expected `usize`, found associated type
   |
   = note:         expected type `usize`
           found associated type `<impl Trait as Trait>::A`
help: consider constraining the associated type `<impl Trait as Trait>::A` to `usize`
   |
LL | fn foo(x: impl Trait<A = usize>) {
   |                     ^^^^^^^^^^
```
This commit is contained in:
Esteban Küber 2020-04-13 13:36:35 -07:00
parent f05a524044
commit 3a795fba03
22 changed files with 469 additions and 66 deletions
Download patch file Download diff file Expand all files Collapse all files

6
src/test/ui/associated-types/associated-types-eq-3.stderr
View file

@ -8,8 +8,10 @@ LL | let _: Bar = x.boo();
|
= note: expected struct `Bar`
found associated type `<I as Foo>::A`
= note: consider constraining the associated type `<I as Foo>::A` to `Bar`
= note: for more information, visit https://doc.rust-lang.org/book/ch19-03-advanced-traits.html
help: consider constraining the associated type `<I as Foo>::A` to `Bar`
|
LL | fn foo2<I: Foo<A = Bar>>(x: I) {
| ^^^^^^^^^
error[E0271]: type mismatch resolving `<isize as Foo>::A == Bar`
--> $DIR/associated-types-eq-3.rs:38:5

2
src/test/ui/associated-types/associated-types-issue-20346.stderr
View file

@ -12,8 +12,6 @@ LL | is_iterator_of::<Option<T>, _>(&adapter);
|
= note: expected enum `std::option::Option<T>`
found type `T`
= help: type parameters must be constrained to match other types
= note: for more information, visit https://doc.rust-lang.org/book/ch10-02-traits.html#traits-as-parameters
error: aborting due to previous error

12
src/test/ui/associated-types/associated-types-multiple-types-one-trait.stderr
View file

@ -9,8 +9,10 @@ LL | fn want_y<T:Foo<Y=i32>>(t: &T) { }
|
= note: expected type `i32`
found associated type `<T as Foo>::Y`
= note: consider constraining the associated type `<T as Foo>::Y` to `i32`
= note: for more information, visit https://doc.rust-lang.org/book/ch19-03-advanced-traits.html
help: consider constraining the associated type `<T as Foo>::Y` to `i32`
|
LL | fn have_x_want_y<T:Foo<X=u32, Y = i32>>(t: &T)
| ^^^^^^^^^
error[E0271]: type mismatch resolving `<T as Foo>::X == u32`
--> $DIR/associated-types-multiple-types-one-trait.rs:18:5
@ -23,8 +25,10 @@ LL | fn want_x<T:Foo<X=u32>>(t: &T) { }
|
= note: expected type `u32`
found associated type `<T as Foo>::X`
= note: consider constraining the associated type `<T as Foo>::X` to `u32`
= note: for more information, visit https://doc.rust-lang.org/book/ch19-03-advanced-traits.html
help: consider constraining the associated type `<T as Foo>::X` to `u32`
|
LL | fn have_y_want_x<T:Foo<Y=i32, X = u32>>(t: &T)
| ^^^^^^^^^
error: aborting due to 2 previous errors

4
src/test/ui/generic-associated-types/iterable.stderr
View file

@ -6,7 +6,7 @@ LL | type Item<'a> where T: 'a = <std::slice::Iter<'a, T> as Iterator>::Item
|
= note: expected reference `&T`
found associated type `<std::vec::Vec<T> as Iterable>::Item<'_>`
= note: consider constraining the associated type `<std::vec::Vec<T> as Iterable>::Item<'_>` to `&_`
= help: consider constraining the associated type `<std::vec::Vec<T> as Iterable>::Item<'_>` to `&_`
= note: for more information, visit https://doc.rust-lang.org/book/ch19-03-advanced-traits.html
error[E0271]: type mismatch resolving `for<'a> <<[T] as Iterable>::Iter<'a> as std::iter::Iterator>::Item == <[T] as Iterable>::Item<'a>`
@ -17,7 +17,7 @@ LL | type Item<'a> where T: 'a = <std::slice::Iter<'a, T> as Iterator>::Item
|
= note: expected reference `&T`
found associated type `<[T] as Iterable>::Item<'_>`
= note: consider constraining the associated type `<[T] as Iterable>::Item<'_>` to `&_`
= help: consider constraining the associated type `<[T] as Iterable>::Item<'_>` to `&_`
= note: for more information, visit https://doc.rust-lang.org/book/ch19-03-advanced-traits.html
error[E0271]: type mismatch resolving `for<'a> <<std::vec::Vec<T> as Iterable>::Iter<'a> as std::iter::Iterator>::Item == <std::vec::Vec<T> as Iterable>::Item<'a>`

2
src/test/ui/hrtb/issue-62203-hrtb-ice.stderr
View file

@ -6,7 +6,7 @@ LL | let v = Unit2.m(
|
= note: expected struct `Unit4`
found associated type `<_ as Ty<'_>>::V`
= note: consider constraining the associated type `<_ as Ty<'_>>::V` to `Unit4`
= help: consider constraining the associated type `<_ as Ty<'_>>::V` to `Unit4`
= note: for more information, visit https://doc.rust-lang.org/book/ch19-03-advanced-traits.html
error[E0271]: type mismatch resolving `<[closure@$DIR/issue-62203-hrtb-ice.rs:42:17: 42:39] as std::ops::FnOnce<((&u8,),)>>::Output == Unit3`

12
src/test/ui/impl-trait/bound-normalization-fail.stderr
View file

@ -14,9 +14,11 @@ LL | fn foo_fail<T: Trait>() -> impl FooLike<Output=T::Assoc> {
|
= note: expected type `()`
found associated type `<T as impl_trait::Trait>::Assoc`
= note: consider constraining the associated type `<T as impl_trait::Trait>::Assoc` to `()`
= note: for more information, visit https://doc.rust-lang.org/book/ch19-03-advanced-traits.html
= note: the return type of a function must have a statically known size
help: consider constraining the associated type `<T as impl_trait::Trait>::Assoc` to `()`
|
LL | fn foo_fail<T: Trait<Assoc = ()>>() -> impl FooLike<Output=T::Assoc> {
| ^^^^^^^^^^^^
error: `impl Trait` return type cannot contain a projection or `Self` that references lifetimes from a parent scope
--> $DIR/bound-normalization-fail.rs:43:41
@ -32,9 +34,11 @@ LL | fn foo2_fail<'a, T: Trait<'a>>() -> impl FooLike<Output=T::Assoc> {
|
= note: expected type `()`
found associated type `<T as lifetimes::Trait<'static>>::Assoc`
= note: consider constraining the associated type `<T as lifetimes::Trait<'static>>::Assoc` to `()`
= note: for more information, visit https://doc.rust-lang.org/book/ch19-03-advanced-traits.html
= note: the return type of a function must have a statically known size
help: consider constraining the associated type `<T as lifetimes::Trait<'static>>::Assoc` to `()`
|
LL | fn foo2_fail<'a, T: Trait<'a, Assoc = ()>>() -> impl FooLike<Output=T::Assoc> {
| ^^^^^^^^^^^^
error: aborting due to 3 previous errors; 1 warning emitted

2
src/test/ui/impl-trait/equality2.stderr
View file

@ -25,7 +25,7 @@ LL | let _: i32 = Leak::leak(hide(0_i32));
|
= note: expected type `i32`
found associated type `<impl Foo as Leak>::T`
= note: consider constraining the associated type `<impl Foo as Leak>::T` to `i32`
= help: consider constraining the associated type `<impl Foo as Leak>::T` to `i32`
= note: for more information, visit https://doc.rust-lang.org/book/ch19-03-advanced-traits.html
error[E0308]: mismatched types

2
src/test/ui/impl-trait/universal-mismatched-type.stderr
View file

@ -10,8 +10,6 @@ LL | x
|
= note: expected struct `std::string::String`
found type parameter `impl Debug`
= help: type parameters must be constrained to match other types
= note: for more information, visit https://doc.rust-lang.org/book/ch10-02-traits.html#traits-as-parameters
error: aborting due to previous error

2
src/test/ui/issues/issue-13853.stderr
View file

@ -9,8 +9,6 @@ LL | self.iter()
|
= note: expected type parameter `I`
found struct `std::slice::Iter<'_, N>`
= help: type parameters must be constrained to match other types
= note: for more information, visit https://doc.rust-lang.org/book/ch10-02-traits.html#traits-as-parameters
error[E0599]: no method named `iter` found for reference `&G` in the current scope
--> $DIR/issue-13853.rs:27:23

6
src/test/ui/issues/issue-20225.stderr
View file

@ -8,8 +8,6 @@ LL | extern "rust-call" fn call(&self, (_,): (T,)) {}
|
= note: expected fn pointer `extern "rust-call" fn(&Foo, (&'a T,))`
found fn pointer `extern "rust-call" fn(&Foo, (T,))`
= help: type parameters must be constrained to match other types
= note: for more information, visit https://doc.rust-lang.org/book/ch10-02-traits.html#traits-as-parameters
error[E0053]: method `call_mut` has an incompatible type for trait
--> $DIR/issue-20225.rs:11:3
@ -21,8 +19,6 @@ LL | extern "rust-call" fn call_mut(&mut self, (_,): (T,)) {}
|
= note: expected fn pointer `extern "rust-call" fn(&mut Foo, (&'a T,))`
found fn pointer `extern "rust-call" fn(&mut Foo, (T,))`
= help: type parameters must be constrained to match other types
= note: for more information, visit https://doc.rust-lang.org/book/ch10-02-traits.html#traits-as-parameters
error[E0053]: method `call_once` has an incompatible type for trait
--> $DIR/issue-20225.rs:18:3
@ -35,8 +31,6 @@ LL | extern "rust-call" fn call_once(self, (_,): (T,)) {}
|
= note: expected fn pointer `extern "rust-call" fn(Foo, (&'a T,))`
found fn pointer `extern "rust-call" fn(Foo, (T,))`
= help: type parameters must be constrained to match other types
= note: for more information, visit https://doc.rust-lang.org/book/ch10-02-traits.html#traits-as-parameters
error: aborting due to 3 previous errors

12
src/test/ui/issues/issue-69306.stderr
View file

@ -8,8 +8,6 @@ LL | const C: S0<u8> = Self(0);
|
= note: expected type parameter `T`
found type `{integer}`
= help: type parameters must be constrained to match other types
= note: for more information, visit https://doc.rust-lang.org/book/ch10-02-traits.html#traits-as-parameters
error[E0308]: mismatched types
--> $DIR/issue-69306.rs:5:23
@ -21,8 +19,6 @@ LL | const C: S0<u8> = Self(0);
|
= note: expected struct `S0<u8>`
found struct `S0<T>`
= help: type parameters must be constrained to match other types
= note: for more information, visit https://doc.rust-lang.org/book/ch10-02-traits.html#traits-as-parameters
error[E0308]: mismatched types
--> $DIR/issue-69306.rs:10:14
@ -35,8 +31,6 @@ LL | Self(0);
|
= note: expected type parameter `T`
found type `{integer}`
= help: type parameters must be constrained to match other types
= note: for more information, visit https://doc.rust-lang.org/book/ch10-02-traits.html#traits-as-parameters
error[E0308]: mismatched types
--> $DIR/issue-69306.rs:27:14
@ -49,8 +43,6 @@ LL | Self(0);
|
= note: expected type parameter `T`
found type `{integer}`
= help: type parameters must be constrained to match other types
= note: for more information, visit https://doc.rust-lang.org/book/ch10-02-traits.html#traits-as-parameters
error[E0308]: mismatched types
--> $DIR/issue-69306.rs:33:32
@ -62,8 +54,6 @@ LL | const C: S1<u8, u8> = Self(0, 1);
|
= note: expected type parameter `T`
found type `{integer}`
= help: type parameters must be constrained to match other types
= note: for more information, visit https://doc.rust-lang.org/book/ch10-02-traits.html#traits-as-parameters
error[E0308]: mismatched types
--> $DIR/issue-69306.rs:33:27
@ -75,8 +65,6 @@ LL | const C: S1<u8, u8> = Self(0, 1);
|
= note: expected struct `S1<u8, _>`
found struct `S1<T, _>`
= help: type parameters must be constrained to match other types
= note: for more information, visit https://doc.rust-lang.org/book/ch10-02-traits.html#traits-as-parameters
error[E0308]: mismatched types
--> $DIR/issue-69306.rs:41:14

2
src/test/ui/mismatched_types/issue-35030.stderr
View file

@ -9,8 +9,6 @@ LL | Some(true)
|
= note: expected type parameter `bool` (type parameter `bool`)
found type `bool` (`bool`)
= help: type parameters must be constrained to match other types
= note: for more information, visit https://doc.rust-lang.org/book/ch10-02-traits.html#traits-as-parameters
error: aborting due to previous error

2
src/test/ui/specialization/specialization-default-projection.stderr
View file

@ -25,7 +25,7 @@ LL | generic::<()>()
|
= note: expected unit type `()`
found associated type `<() as Foo>::Assoc`
= note: consider constraining the associated type `<() as Foo>::Assoc` to `()`
= help: consider constraining the associated type `<() as Foo>::Assoc` to `()`
= note: for more information, visit https://doc.rust-lang.org/book/ch19-03-advanced-traits.html
error: aborting due to 2 previous errors

2
src/test/ui/specialization/specialization-default-types.stderr
View file

@ -21,7 +21,7 @@ LL | Example::generate(t)
|
= note: expected struct `std::boxed::Box<T>`
found associated type `<T as Example>::Output`
= note: consider constraining the associated type `<T as Example>::Output` to `std::boxed::Box<T>`
= help: consider constraining the associated type `<T as Example>::Output` to `std::boxed::Box<T>`
= note: for more information, visit https://doc.rust-lang.org/book/ch19-03-advanced-traits.html
error: aborting due to 2 previous errors

2
src/test/ui/suggestions/expected-boxed-future-isnt-pinned.stderr
View file

@ -12,8 +12,6 @@ LL | x
|
= note: expected struct `std::pin::Pin<std::boxed::Box<(dyn std::future::Future<Output = i32> + std::marker::Send + 'static)>>`
found type parameter `F`
= help: type parameters must be constrained to match other types
= note: for more information, visit https://doc.rust-lang.org/book/ch10-02-traits.html#traits-as-parameters
error[E0308]: mismatched types
--> $DIR/expected-boxed-future-isnt-pinned.rs:18:5

43
src/test/ui/suggestions/trait-with-missing-associated-type-restriction-fixable.fixed Normal file
View file

@ -0,0 +1,43 @@
// run-rustfix
#![allow(unused)] // for the fixed file
trait Trait<T = Self> {
type A;
fn func(&self) -> Self::A;
}
struct S<T>(T);
impl<K> S<K> {
fn foo<'a, T: Trait + 'a>(&self, _: impl Trait, x: impl Trait<A = usize>, _: T) {
qux(x.func()) //~ ERROR mismatched types
}
fn ban<T>(x: T) where T: Trait<A = usize> {
qux(x.func()) //~ ERROR mismatched types
}
}
fn foo<'a, T: Trait + 'a>(_: impl Trait, x: impl Trait<A = usize>, _: T) {
qux(x.func()) //~ ERROR mismatched types
}
fn bar<T: Trait<A = usize>>(x: T) {
qux(x.func()) //~ ERROR mismatched types
}
fn foo2(x: impl Trait<i32, A = usize>) {
qux(x.func()) //~ ERROR mismatched types
}
fn bar2<T: Trait<i32, A = usize>>(x: T) {
qux(x.func()) //~ ERROR mismatched types
}
fn ban<T>(x: T) where T: Trait<A = usize> {
qux(x.func()) //~ ERROR mismatched types
}
fn qux(_: usize) {}
fn main() {}

43
src/test/ui/suggestions/trait-with-missing-associated-type-restriction-fixable.rs Normal file
View file

@ -0,0 +1,43 @@
// run-rustfix
#![allow(unused)] // for the fixed file
trait Trait<T = Self> {
type A;
fn func(&self) -> Self::A;
}
struct S<T>(T);
impl<K> S<K> {
fn foo<'a, T: Trait + 'a>(&self, _: impl Trait, x: impl Trait, _: T) {
qux(x.func()) //~ ERROR mismatched types
}
fn ban<T>(x: T) where T: Trait {
qux(x.func()) //~ ERROR mismatched types
}
}
fn foo<'a, T: Trait + 'a>(_: impl Trait, x: impl Trait, _: T) {
qux(x.func()) //~ ERROR mismatched types
}
fn bar<T: Trait>(x: T) {
qux(x.func()) //~ ERROR mismatched types
}
fn foo2(x: impl Trait<i32>) {
qux(x.func()) //~ ERROR mismatched types
}
fn bar2<T: Trait<i32>>(x: T) {
qux(x.func()) //~ ERROR mismatched types
}
fn ban<T>(x: T) where T: Trait {
qux(x.func()) //~ ERROR mismatched types
}
fn qux(_: usize) {}
fn main() {}

94
src/test/ui/suggestions/trait-with-missing-associated-type-restriction-fixable.stderr Normal file
View file

@ -0,0 +1,94 @@
error[E0308]: mismatched types
--> $DIR/trait-with-missing-associated-type-restriction-fixable.rs:13:13
|
LL | qux(x.func())
| ^^^^^^^^ expected `usize`, found associated type
|
= note: expected type `usize`
found associated type `<impl Trait as Trait>::A`
help: consider constraining the associated type `<impl Trait as Trait>::A` to `usize`
|
LL | fn foo<'a, T: Trait + 'a>(&self, _: impl Trait, x: impl Trait<A = usize>, _: T) {
| ^^^^^^^^^^^
error[E0308]: mismatched types
--> $DIR/trait-with-missing-associated-type-restriction-fixable.rs:17:13
|
LL | qux(x.func())
| ^^^^^^^^ expected `usize`, found associated type
|
= note: expected type `usize`
found associated type `<T as Trait>::A`
help: consider constraining the associated type `<T as Trait>::A` to `usize`
|
LL | fn ban<T>(x: T) where T: Trait<A = usize> {
| ^^^^^^^^^^^
error[E0308]: mismatched types
--> $DIR/trait-with-missing-associated-type-restriction-fixable.rs:22:9
|
LL | qux(x.func())
| ^^^^^^^^ expected `usize`, found associated type
|
= note: expected type `usize`
found associated type `<impl Trait as Trait>::A`
help: consider constraining the associated type `<impl Trait as Trait>::A` to `usize`
|
LL | fn foo<'a, T: Trait + 'a>(_: impl Trait, x: impl Trait<A = usize>, _: T) {
| ^^^^^^^^^^^
error[E0308]: mismatched types
--> $DIR/trait-with-missing-associated-type-restriction-fixable.rs:26:9
|
LL | qux(x.func())
| ^^^^^^^^ expected `usize`, found associated type
|
= note: expected type `usize`
found associated type `<T as Trait>::A`
help: consider constraining the associated type `<T as Trait>::A` to `usize`
|
LL | fn bar<T: Trait<A = usize>>(x: T) {
| ^^^^^^^^^^^
error[E0308]: mismatched types
--> $DIR/trait-with-missing-associated-type-restriction-fixable.rs:30:9
|
LL | qux(x.func())
| ^^^^^^^^ expected `usize`, found associated type
|
= note: expected type `usize`
found associated type `<impl Trait<i32> as Trait<i32>>::A`
help: consider constraining the associated type `<impl Trait<i32> as Trait<i32>>::A` to `usize`
|
LL | fn foo2(x: impl Trait<i32, A = usize>) {
| ^^^^^^^^^^^
error[E0308]: mismatched types
--> $DIR/trait-with-missing-associated-type-restriction-fixable.rs:34:9
|
LL | qux(x.func())
| ^^^^^^^^ expected `usize`, found associated type
|
= note: expected type `usize`
found associated type `<T as Trait<i32>>::A`
help: consider constraining the associated type `<T as Trait<i32>>::A` to `usize`
|
LL | fn bar2<T: Trait<i32, A = usize>>(x: T) {
| ^^^^^^^^^^^
error[E0308]: mismatched types
--> $DIR/trait-with-missing-associated-type-restriction-fixable.rs:38:9
|
LL | qux(x.func())
| ^^^^^^^^ expected `usize`, found associated type
|
= note: expected type `usize`
found associated type `<T as Trait>::A`
help: consider constraining the associated type `<T as Trait>::A` to `usize`
|
LL | fn ban<T>(x: T) where T: Trait<A = usize> {
| ^^^^^^^^^^^
error: aborting due to 7 previous errors
For more information about this error, try `rustc --explain E0308`.

41
src/test/ui/suggestions/trait-with-missing-associated-type-restriction.rs Normal file
View file

@ -0,0 +1,41 @@
// These are all the possible variations of this error I could think of for.
// `trait-with-missing-associated-type-restriction-fixable.rs` contains the subset of these that
// can be fixed with `rustfix`.
trait Trait<T = Self> {
type A;
fn func(&self) -> Self::A;
}
fn foo(_: impl Trait, x: impl Trait) {
qux(x.func()) //~ ERROR mismatched types
}
fn bar<T: Trait>(x: T) {
qux(x.func()) //~ ERROR mismatched types
}
fn foo2(x: impl Trait<i32>) {
qux(x.func()) //~ ERROR mismatched types
}
fn bar2<T: Trait<i32>>(x: T) {
qux(x.func()) //~ ERROR mismatched types
}
fn baz<D: std::fmt::Debug, T: Trait<A = D>>(x: T) {
qux(x.func()) //~ ERROR mismatched types
}
fn bat(x: &mut dyn Trait<(), A = ()>) {
qux(x) //~ ERROR mismatched types
}
fn ban<T>(x: T) where T: Trait {
qux(x.func()) //~ ERROR mismatched types
}
fn qux(_: usize) {}
fn main() {}

88
src/test/ui/suggestions/trait-with-missing-associated-type-restriction.stderr Normal file
View file

@ -0,0 +1,88 @@
error[E0308]: mismatched types
--> $DIR/trait-with-missing-associated-type-restriction.rs:12:9
|
LL | qux(x.func())
| ^^^^^^^^ expected `usize`, found associated type
|
= note: expected type `usize`
found associated type `<impl Trait as Trait>::A`
help: consider constraining the associated type `<impl Trait as Trait>::A` to `usize`
|
LL | fn foo(_: impl Trait, x: impl Trait<A = usize>) {
| ^^^^^^^^^^^
error[E0308]: mismatched types
--> $DIR/trait-with-missing-associated-type-restriction.rs:16:9
|
LL | qux(x.func())
| ^^^^^^^^ expected `usize`, found associated type
|
= note: expected type `usize`
found associated type `<T as Trait>::A`
help: consider constraining the associated type `<T as Trait>::A` to `usize`
|
LL | fn bar<T: Trait<A = usize>>(x: T) {
| ^^^^^^^^^^^
error[E0308]: mismatched types
--> $DIR/trait-with-missing-associated-type-restriction.rs:20:9
|
LL | qux(x.func())
| ^^^^^^^^ expected `usize`, found associated type
|
= note: expected type `usize`
found associated type `<impl Trait<i32> as Trait<i32>>::A`
help: consider constraining the associated type `<impl Trait<i32> as Trait<i32>>::A` to `usize`
|
LL | fn foo2(x: impl Trait<i32, A = usize>) {
| ^^^^^^^^^^^
error[E0308]: mismatched types
--> $DIR/trait-with-missing-associated-type-restriction.rs:24:9
|
LL | qux(x.func())
| ^^^^^^^^ expected `usize`, found associated type
|
= note: expected type `usize`
found associated type `<T as Trait<i32>>::A`
help: consider constraining the associated type `<T as Trait<i32>>::A` to `usize`
|
LL | fn bar2<T: Trait<i32, A = usize>>(x: T) {
| ^^^^^^^^^^^
error[E0308]: mismatched types
--> $DIR/trait-with-missing-associated-type-restriction.rs:28:9
|
LL | fn baz<D: std::fmt::Debug, T: Trait<A = D>>(x: T) {
| - this type parameter
LL | qux(x.func())
| ^^^^^^^^ expected `usize`, found type parameter `D`
|
= note: expected type `usize`
found type parameter `D`
error[E0308]: mismatched types
--> $DIR/trait-with-missing-associated-type-restriction.rs:32:9
|
LL | qux(x)
| ^ expected `usize`, found mutable reference
|
= note: expected type `usize`
found mutable reference `&mut dyn Trait<(), A = ()>`
error[E0308]: mismatched types
--> $DIR/trait-with-missing-associated-type-restriction.rs:36:9
|
LL | qux(x.func())
| ^^^^^^^^ expected `usize`, found associated type
|
= note: expected type `usize`
found associated type `<T as Trait>::A`
help: consider constraining the associated type `<T as Trait>::A` to `usize`
|
LL | fn ban<T>(x: T) where T: Trait<A = usize> {
| ^^^^^^^^^^^
error: aborting due to 7 previous errors
For more information about this error, try `rustc --explain E0308`.

12
src/test/ui/type-alias-enum-variants/enum-variant-generic-args.stderr
View file

@ -9,8 +9,6 @@ LL | Self::TSVariant(());
|
= note: expected type parameter `T`
found unit type `()`
= help: type parameters must be constrained to match other types
= note: for more information, visit https://doc.rust-lang.org/book/ch10-02-traits.html#traits-as-parameters
error[E0109]: type arguments are not allowed for this type
--> $DIR/enum-variant-generic-args.rs:15:27
@ -35,8 +33,6 @@ LL | Self::<()>::TSVariant(());
|
= note: expected type parameter `T`
found unit type `()`
= help: type parameters must be constrained to match other types
= note: for more information, visit https://doc.rust-lang.org/book/ch10-02-traits.html#traits-as-parameters
error[E0109]: type arguments are not allowed for this type
--> $DIR/enum-variant-generic-args.rs:20:16
@ -61,8 +57,6 @@ LL | Self::SVariant { v: () };
|
= note: expected type parameter `T`
found unit type `()`
= help: type parameters must be constrained to match other types
= note: for more information, visit https://doc.rust-lang.org/book/ch10-02-traits.html#traits-as-parameters
error[E0109]: type arguments are not allowed for this type
--> $DIR/enum-variant-generic-args.rs:28:26
@ -81,8 +75,6 @@ LL | Self::SVariant::<()> { v: () };
|
= note: expected type parameter `T`
found unit type `()`
= help: type parameters must be constrained to match other types
= note: for more information, visit https://doc.rust-lang.org/book/ch10-02-traits.html#traits-as-parameters
error[E0109]: type arguments are not allowed for this type
--> $DIR/enum-variant-generic-args.rs:31:16
@ -101,8 +93,6 @@ LL | Self::<()>::SVariant { v: () };
|
= note: expected type parameter `T`
found unit type `()`
= help: type parameters must be constrained to match other types
= note: for more information, visit https://doc.rust-lang.org/book/ch10-02-traits.html#traits-as-parameters
error[E0109]: type arguments are not allowed for this type
--> $DIR/enum-variant-generic-args.rs:34:16
@ -127,8 +117,6 @@ LL | Self::<()>::SVariant::<()> { v: () };
|
= note: expected type parameter `T`
found unit type `()`
= help: type parameters must be constrained to match other types
= note: for more information, visit https://doc.rust-lang.org/book/ch10-02-traits.html#traits-as-parameters
error[E0109]: type arguments are not allowed for this type
--> $DIR/enum-variant-generic-args.rs:41:26