For a single impl candidate, try to unify it with error trait ref

15 files changed, 31 insertions, 31 deletions

diff --git a/tests/ui/const-generics/occurs-check/unused-substs-1.stderr b/tests/ui/const-generics/occurs-check/unused-substs-1.stderr
index 51ef354e3ed..61d055e8084 100644
--- a/tests/ui/const-generics/occurs-check/unused-substs-1.stderr
+++ b/tests/ui/const-generics/occurs-check/unused-substs-1.stderr
@@ -4,7 +4,7 @@ error[E0277]: the trait bound `A<_>: Bar<_>` is not satisfied
 LL |     let _ = A;
    |             ^ the trait `Bar<_>` is not implemented for `A<_>`
    |
-   = help: the trait `Bar<N>` is implemented for `A<7>`
+   = help: the trait `Bar<_>` is implemented for `A<7>`
 note: required by a bound in `A`
   --> $DIR/unused-substs-1.rs:9:11
    |
diff --git a/tests/ui/impl-trait/issues/issue-62742.stderr b/tests/ui/impl-trait/issues/issue-62742.stderr
index d872291c870..7592a850682 100644
--- a/tests/ui/impl-trait/issues/issue-62742.stderr
+++ b/tests/ui/impl-trait/issues/issue-62742.stderr
@@ -4,7 +4,7 @@ error[E0277]: the trait bound `RawImpl<_>: Raw<_>` is not satisfied
 LL |     WrongImpl::foo(0i32);
    |     ^^^^^^^^^ the trait `Raw<_>` is not implemented for `RawImpl<_>`
    |
-   = help: the trait `Raw<[T]>` is implemented for `RawImpl<T>`
+   = help: the trait `Raw<[_]>` is implemented for `RawImpl<_>`
 note: required by a bound in `SafeImpl`
   --> $DIR/issue-62742.rs:26:35
    |
@@ -42,7 +42,7 @@ error[E0277]: the trait bound `RawImpl<()>: Raw<()>` is not satisfied
 LL |     WrongImpl::<()>::foo(0i32);
    |     ^^^^^^^^^^^^^^^ the trait `Raw<()>` is not implemented for `RawImpl<()>`
    |
-   = help: the trait `Raw<[T]>` is implemented for `RawImpl<T>`
+   = help: the trait `Raw<[()]>` is implemented for `RawImpl<()>`
 note: required by a bound in `SafeImpl`
   --> $DIR/issue-62742.rs:26:35
    |
diff --git a/tests/ui/indexing/index-help.stderr b/tests/ui/indexing/index-help.stderr
index e020d029875..d3310ceb053 100644
--- a/tests/ui/indexing/index-help.stderr
+++ b/tests/ui/indexing/index-help.stderr
@@ -5,7 +5,7 @@ LL |     x[0i32];
    |       ^^^^ slice indices are of type `usize` or ranges of `usize`
    |
    = help: the trait `SliceIndex<[{integer}]>` is not implemented for `i32`
-   = help: the trait `SliceIndex<[T]>` is implemented for `usize`
+   = help: the trait `SliceIndex<[{integer}]>` is implemented for `usize`
    = note: required for `Vec<{integer}>` to implement `Index<i32>`
 
 error: aborting due to previous error
diff --git a/tests/ui/indexing/indexing-requires-a-uint.stderr b/tests/ui/indexing/indexing-requires-a-uint.stderr
index 7a741cfc7de..fcfac3a5e93 100644
--- a/tests/ui/indexing/indexing-requires-a-uint.stderr
+++ b/tests/ui/indexing/indexing-requires-a-uint.stderr
@@ -5,7 +5,7 @@ LL |     [0][0u8];
    |         ^^^ slice indices are of type `usize` or ranges of `usize`
    |
    = help: the trait `SliceIndex<[{integer}]>` is not implemented for `u8`
-   = help: the trait `SliceIndex<[T]>` is implemented for `usize`
+   = help: the trait `SliceIndex<[{integer}]>` is implemented for `usize`
    = note: required for `[{integer}]` to implement `Index<u8>`
 
 error[E0308]: mismatched types
diff --git a/tests/ui/integral-indexing.stderr b/tests/ui/integral-indexing.stderr
index bbbb2a86a22..b7d80565a1e 100644
--- a/tests/ui/integral-indexing.stderr
+++ b/tests/ui/integral-indexing.stderr
@@ -5,7 +5,7 @@ LL |     v[3u8];
    |       ^^^ slice indices are of type `usize` or ranges of `usize`
    |
    = help: the trait `SliceIndex<[isize]>` is not implemented for `u8`
-   = help: the trait `SliceIndex<[T]>` is implemented for `usize`
+   = help: the trait `SliceIndex<[isize]>` is implemented for `usize`
    = note: required for `Vec<isize>` to implement `Index<u8>`
 
 error[E0277]: the type `[isize]` cannot be indexed by `i8`
@@ -15,7 +15,7 @@ LL |     v[3i8];
    |       ^^^ slice indices are of type `usize` or ranges of `usize`
    |
    = help: the trait `SliceIndex<[isize]>` is not implemented for `i8`
-   = help: the trait `SliceIndex<[T]>` is implemented for `usize`
+   = help: the trait `SliceIndex<[isize]>` is implemented for `usize`
    = note: required for `Vec<isize>` to implement `Index<i8>`
 
 error[E0277]: the type `[isize]` cannot be indexed by `u32`
@@ -25,7 +25,7 @@ LL |     v[3u32];
    |       ^^^^ slice indices are of type `usize` or ranges of `usize`
    |
    = help: the trait `SliceIndex<[isize]>` is not implemented for `u32`
-   = help: the trait `SliceIndex<[T]>` is implemented for `usize`
+   = help: the trait `SliceIndex<[isize]>` is implemented for `usize`
    = note: required for `Vec<isize>` to implement `Index<u32>`
 
 error[E0277]: the type `[isize]` cannot be indexed by `i32`
@@ -35,7 +35,7 @@ LL |     v[3i32];
    |       ^^^^ slice indices are of type `usize` or ranges of `usize`
    |
    = help: the trait `SliceIndex<[isize]>` is not implemented for `i32`
-   = help: the trait `SliceIndex<[T]>` is implemented for `usize`
+   = help: the trait `SliceIndex<[isize]>` is implemented for `usize`
    = note: required for `Vec<isize>` to implement `Index<i32>`
 
 error[E0277]: the type `[u8]` cannot be indexed by `u8`
@@ -45,7 +45,7 @@ LL |     s.as_bytes()[3u8];
    |                  ^^^ slice indices are of type `usize` or ranges of `usize`
    |
    = help: the trait `SliceIndex<[u8]>` is not implemented for `u8`
-   = help: the trait `SliceIndex<[T]>` is implemented for `usize`
+   = help: the trait `SliceIndex<[u8]>` is implemented for `usize`
    = note: required for `[u8]` to implement `Index<u8>`
 
 error[E0277]: the type `[u8]` cannot be indexed by `i8`
@@ -55,7 +55,7 @@ LL |     s.as_bytes()[3i8];
    |                  ^^^ slice indices are of type `usize` or ranges of `usize`
    |
    = help: the trait `SliceIndex<[u8]>` is not implemented for `i8`
-   = help: the trait `SliceIndex<[T]>` is implemented for `usize`
+   = help: the trait `SliceIndex<[u8]>` is implemented for `usize`
    = note: required for `[u8]` to implement `Index<i8>`
 
 error[E0277]: the type `[u8]` cannot be indexed by `u32`
@@ -65,7 +65,7 @@ LL |     s.as_bytes()[3u32];
    |                  ^^^^ slice indices are of type `usize` or ranges of `usize`
    |
    = help: the trait `SliceIndex<[u8]>` is not implemented for `u32`
-   = help: the trait `SliceIndex<[T]>` is implemented for `usize`
+   = help: the trait `SliceIndex<[u8]>` is implemented for `usize`
    = note: required for `[u8]` to implement `Index<u32>`
 
 error[E0277]: the type `[u8]` cannot be indexed by `i32`
@@ -75,7 +75,7 @@ LL |     s.as_bytes()[3i32];
    |                  ^^^^ slice indices are of type `usize` or ranges of `usize`
    |
    = help: the trait `SliceIndex<[u8]>` is not implemented for `i32`
-   = help: the trait `SliceIndex<[T]>` is implemented for `usize`
+   = help: the trait `SliceIndex<[u8]>` is implemented for `usize`
    = note: required for `[u8]` to implement `Index<i32>`
 
 error: aborting due to 8 previous errors
diff --git a/tests/ui/issues/issue-34334.stderr b/tests/ui/issues/issue-34334.stderr
index 9d2c315e4db..bacae965eed 100644
--- a/tests/ui/issues/issue-34334.stderr
+++ b/tests/ui/issues/issue-34334.stderr
@@ -19,7 +19,7 @@ LL |     let sr2: Vec<(u32, _, _)> = sr.iter().map(|(faction, th_sender, th_rece
    |                                                                                       ^^^^^^^ value of type `Vec<(u32, _, _)>` cannot be built from `std::iter::Iterator<Item=()>`
    |
    = help: the trait `FromIterator<()>` is not implemented for `Vec<(u32, _, _)>`
-   = help: the trait `FromIterator<T>` is implemented for `Vec<T>`
+   = help: the trait `FromIterator<(u32, _, _)>` is implemented for `Vec<(u32, _, _)>`
 note: the method call chain might not have had the expected associated types
   --> $DIR/issue-34334.rs:5:43
    |
diff --git a/tests/ui/issues/issue-66923-show-error-for-correct-call.stderr b/tests/ui/issues/issue-66923-show-error-for-correct-call.stderr
index 22b1da64cb3..48cd549cb33 100644
--- a/tests/ui/issues/issue-66923-show-error-for-correct-call.stderr
+++ b/tests/ui/issues/issue-66923-show-error-for-correct-call.stderr
@@ -5,7 +5,7 @@ LL |     let x2: Vec<f64> = x1.into_iter().collect();
    |                                       ^^^^^^^ value of type `Vec<f64>` cannot be built from `std::iter::Iterator<Item=&f64>`
    |
    = help: the trait `FromIterator<&f64>` is not implemented for `Vec<f64>`
-   = help: the trait `FromIterator<T>` is implemented for `Vec<T>`
+   = help: the trait `FromIterator<f64>` is implemented for `Vec<f64>`
 note: the method call chain might not have had the expected associated types
   --> $DIR/issue-66923-show-error-for-correct-call.rs:8:27
    |
@@ -25,7 +25,7 @@ LL |     let x3 = x1.into_iter().collect::<Vec<f64>>();
    |                             required by a bound introduced by this call
    |
    = help: the trait `FromIterator<&f64>` is not implemented for `Vec<f64>`
-   = help: the trait `FromIterator<T>` is implemented for `Vec<T>`
+   = help: the trait `FromIterator<f64>` is implemented for `Vec<f64>`
 note: the method call chain might not have had the expected associated types
   --> $DIR/issue-66923-show-error-for-correct-call.rs:12:17
    |
diff --git a/tests/ui/iterators/invalid-iterator-chain.stderr b/tests/ui/iterators/invalid-iterator-chain.stderr
index b355da5cb76..1d7cf039972 100644
--- a/tests/ui/iterators/invalid-iterator-chain.stderr
+++ b/tests/ui/iterators/invalid-iterator-chain.stderr
@@ -5,7 +5,7 @@ LL |     i.collect()
    |       ^^^^^^^ value of type `Vec<X>` cannot be built from `std::iter::Iterator<Item=&X>`
    |
    = help: the trait `FromIterator<&X>` is not implemented for `Vec<X>`
-   = help: the trait `FromIterator<T>` is implemented for `Vec<T>`
+   = help: the trait `FromIterator<X>` is implemented for `Vec<X>`
 note: the method call chain might not have had the expected associated types
   --> $DIR/invalid-iterator-chain.rs:4:26
    |
@@ -159,7 +159,7 @@ LL |     let g: Vec<i32> = f.collect();
    |                         ^^^^^^^ value of type `Vec<i32>` cannot be built from `std::iter::Iterator<Item=()>`
    |
    = help: the trait `FromIterator<()>` is not implemented for `Vec<i32>`
-   = help: the trait `FromIterator<T>` is implemented for `Vec<T>`
+   = help: the trait `FromIterator<i32>` is implemented for `Vec<i32>`
 note: the method call chain might not have had the expected associated types
   --> $DIR/invalid-iterator-chain.rs:44:15
    |
diff --git a/tests/ui/on-unimplemented/impl-substs.stderr b/tests/ui/on-unimplemented/impl-substs.stderr
index a0fad0acd0b..018068c1af1 100644
--- a/tests/ui/on-unimplemented/impl-substs.stderr
+++ b/tests/ui/on-unimplemented/impl-substs.stderr
@@ -7,7 +7,7 @@ LL |     Foo::<usize>::foo((1i32, 1i32, 1i32));
    |     required by a bound introduced by this call
    |
    = help: the trait `Foo<usize>` is not implemented for `(i32, i32, i32)`
-   = help: the trait `Foo<A>` is implemented for `(A, B, C)`
+   = help: the trait `Foo<i32>` is implemented for `(i32, i32, i32)`
 
 error: aborting due to previous error
 
diff --git a/tests/ui/on-unimplemented/slice-index.stderr b/tests/ui/on-unimplemented/slice-index.stderr
index b9bca211f43..d378470a368 100644
--- a/tests/ui/on-unimplemented/slice-index.stderr
+++ b/tests/ui/on-unimplemented/slice-index.stderr
@@ -5,7 +5,7 @@ LL |     x[1i32];
    |       ^^^^ slice indices are of type `usize` or ranges of `usize`
    |
    = help: the trait `SliceIndex<[i32]>` is not implemented for `i32`
-   = help: the trait `SliceIndex<[T]>` is implemented for `usize`
+   = help: the trait `SliceIndex<[i32]>` is implemented for `usize`
    = note: required for `[i32]` to implement `Index<i32>`
 
 error[E0277]: the type `[i32]` cannot be indexed by `RangeTo<i32>`
diff --git a/tests/ui/str/str-idx.stderr b/tests/ui/str/str-idx.stderr
index cb1a6fcacfc..3b4cb5e6a19 100644
--- a/tests/ui/str/str-idx.stderr
+++ b/tests/ui/str/str-idx.stderr
@@ -7,7 +7,7 @@ LL |     let _: u8 = s[4];
    = help: the trait `SliceIndex<str>` is not implemented for `{integer}`
    = note: you can use `.chars().nth()` or `.bytes().nth()`
            for more information, see chapter 8 in The Book: <https://doc.rust-lang.org/book/ch08-02-strings.html#indexing-into-strings>
-   = help: the trait `SliceIndex<[T]>` is implemented for `usize`
+   = help: the trait `SliceIndex<[_]>` is implemented for `usize`
    = note: required for `str` to implement `Index<{integer}>`
 
 error[E0277]: the type `str` cannot be indexed by `{integer}`
@@ -21,7 +21,7 @@ LL |     let _ = s.get(4);
    = help: the trait `SliceIndex<str>` is not implemented for `{integer}`
    = note: you can use `.chars().nth()` or `.bytes().nth()`
            for more information, see chapter 8 in The Book: <https://doc.rust-lang.org/book/ch08-02-strings.html#indexing-into-strings>
-   = help: the trait `SliceIndex<[T]>` is implemented for `usize`
+   = help: the trait `SliceIndex<[_]>` is implemented for `usize`
 note: required by a bound in `core::str::<impl str>::get`
   --> $SRC_DIR/core/src/str/mod.rs:LL:COL
 
@@ -36,7 +36,7 @@ LL |     let _ = s.get_unchecked(4);
    = help: the trait `SliceIndex<str>` is not implemented for `{integer}`
    = note: you can use `.chars().nth()` or `.bytes().nth()`
            for more information, see chapter 8 in The Book: <https://doc.rust-lang.org/book/ch08-02-strings.html#indexing-into-strings>
-   = help: the trait `SliceIndex<[T]>` is implemented for `usize`
+   = help: the trait `SliceIndex<[_]>` is implemented for `usize`
 note: required by a bound in `core::str::<impl str>::get_unchecked`
   --> $SRC_DIR/core/src/str/mod.rs:LL:COL
 
diff --git a/tests/ui/str/str-mut-idx.stderr b/tests/ui/str/str-mut-idx.stderr
index ca4b86ba306..f22ecea6257 100644
--- a/tests/ui/str/str-mut-idx.stderr
+++ b/tests/ui/str/str-mut-idx.stderr
@@ -31,7 +31,7 @@ LL |     s[1usize] = bot();
    |       ^^^^^^ string indices are ranges of `usize`
    |
    = help: the trait `SliceIndex<str>` is not implemented for `usize`
-   = help: the trait `SliceIndex<[T]>` is implemented for `usize`
+   = help: the trait `SliceIndex<[_]>` is implemented for `usize`
    = note: required for `str` to implement `Index<usize>`
 
 error[E0277]: the type `str` cannot be indexed by `{integer}`
@@ -45,7 +45,7 @@ LL |     s.get_mut(1);
    = help: the trait `SliceIndex<str>` is not implemented for `{integer}`
    = note: you can use `.chars().nth()` or `.bytes().nth()`
            for more information, see chapter 8 in The Book: <https://doc.rust-lang.org/book/ch08-02-strings.html#indexing-into-strings>
-   = help: the trait `SliceIndex<[T]>` is implemented for `usize`
+   = help: the trait `SliceIndex<[_]>` is implemented for `usize`
 note: required by a bound in `core::str::<impl str>::get_mut`
   --> $SRC_DIR/core/src/str/mod.rs:LL:COL
 
@@ -60,7 +60,7 @@ LL |     s.get_unchecked_mut(1);
    = help: the trait `SliceIndex<str>` is not implemented for `{integer}`
    = note: you can use `.chars().nth()` or `.bytes().nth()`
            for more information, see chapter 8 in The Book: <https://doc.rust-lang.org/book/ch08-02-strings.html#indexing-into-strings>
-   = help: the trait `SliceIndex<[T]>` is implemented for `usize`
+   = help: the trait `SliceIndex<[_]>` is implemented for `usize`
 note: required by a bound in `core::str::<impl str>::get_unchecked_mut`
   --> $SRC_DIR/core/src/str/mod.rs:LL:COL
 
diff --git a/tests/ui/suggestions/issue-101623.stderr b/tests/ui/suggestions/issue-101623.stderr
index 361483cc08d..cfb5c6ae191 100644
--- a/tests/ui/suggestions/issue-101623.stderr
+++ b/tests/ui/suggestions/issue-101623.stderr
@@ -7,7 +7,7 @@ LL |     Trait::do_stuff({ fun(&mut *inner) });
    |     |               the trait `Trait<'_>` is not implemented for `*mut ()`
    |     required by a bound introduced by this call
    |
-   = help: the trait `Trait<'a>` is implemented for `()`
+   = help: the trait `Trait<'_>` is implemented for `()`
 
 error: aborting due to previous error
 
diff --git a/tests/ui/suggestions/suggest-dereferencing-index.stderr b/tests/ui/suggestions/suggest-dereferencing-index.stderr
index 147dc9234c5..47cb25de627 100644
--- a/tests/ui/suggestions/suggest-dereferencing-index.stderr
+++ b/tests/ui/suggestions/suggest-dereferencing-index.stderr
@@ -5,7 +5,7 @@ LL |     let one_item_please: i32 = [1, 2, 3][i];
    |                                          ^ slice indices are of type `usize` or ranges of `usize`
    |
    = help: the trait `SliceIndex<[{integer}]>` is not implemented for `&usize`
-   = help: the trait `SliceIndex<[T]>` is implemented for `usize`
+   = help: the trait `SliceIndex<[{integer}]>` is implemented for `usize`
    = note: required for `[{integer}]` to implement `Index<&usize>`
 help: dereference this index
    |
diff --git a/tests/ui/try-trait/bad-interconversion.stderr b/tests/ui/try-trait/bad-interconversion.stderr
index 7eb392faa66..7039a5c5495 100644
--- a/tests/ui/try-trait/bad-interconversion.stderr
+++ b/tests/ui/try-trait/bad-interconversion.stderr
@@ -73,7 +73,7 @@ LL |     ControlFlow::Continue(Err("hello")?)
    |                                       ^ this `?` produces `Result<Infallible, &str>`, which is incompatible with `ControlFlow<String>`
    |
    = help: the trait `FromResidual<Result<Infallible, &str>>` is not implemented for `ControlFlow<String>`
-   = help: the trait `FromResidual` is implemented for `ControlFlow<B, C>`
+   = help: the trait `FromResidual<ControlFlow<String, Infallible>>` is implemented for `ControlFlow<String>`
 
 error[E0277]: the `?` operator can only be used on `ControlFlow`s in a function that returns `ControlFlow`
   --> $DIR/bad-interconversion.rs:37:12
@@ -84,7 +84,7 @@ LL |     Some(3)?;
    |            ^ this `?` produces `Option<Infallible>`, which is incompatible with `ControlFlow<u64>`
    |
    = help: the trait `FromResidual<Option<Infallible>>` is not implemented for `ControlFlow<u64>`
-   = help: the trait `FromResidual` is implemented for `ControlFlow<B, C>`
+   = help: the trait `FromResidual<ControlFlow<u64, Infallible>>` is implemented for `ControlFlow<u64>`
 
 error[E0277]: the `?` operator in a function that returns `ControlFlow<B, _>` can only be used on other `ControlFlow<B, _>`s (with the same Break type)
   --> $DIR/bad-interconversion.rs:43:29
@@ -96,7 +96,7 @@ LL |     ControlFlow::Break(4_u8)?;
    |
    = help: the trait `FromResidual<ControlFlow<u8, Infallible>>` is not implemented for `ControlFlow<i64>`
    = note: unlike `Result`, there's no `From`-conversion performed for `ControlFlow`
-   = help: the trait `FromResidual` is implemented for `ControlFlow<B, C>`
+   = help: the trait `FromResidual<ControlFlow<i64, Infallible>>` is implemented for `ControlFlow<i64>`
 
 error: aborting due to 8 previous errors