Rollup merge of #71426 - contrun:fix-e0751-explanation, r=estebank

fix error code in E0751.md

reference: https://github.com/rust-lang/rust/issues/71304

src/librustc_error_codes/error_codes/E0751.md

@@ -2,7 +2,7 @@ There are both a positive and negative trait implementation for the same type.
 
 Erroneous code example:
 
-```compile_fail,E0748
+```compile_fail,E0751
 trait MyTrait {}
 impl MyTrait for i32 { }
 impl !MyTrait for i32 { }

src/librustc_trait_selection/traits/specialize/mod.rs

@@ -345,7 +345,7 @@ fn report_negative_positive_conflict(
     let mut err = struct_span_err!(
         tcx.sess,
         impl_span,
-        E0748,
+        E0751,
         "found both positive and negative implementation of trait `{}`{}:",
         overlap.trait_desc,
         overlap.self_desc.clone().map_or(String::new(), |ty| format!(" for type `{}`", ty))

src/test/ui/coherence/coherence-conflicting-negative-trait-impl.stderr

@@ -1,4 +1,4 @@
-error[E0748]: found both positive and negative implementation of trait `std::marker::Send` for type `TestType<_>`:
+error[E0751]: found both positive and negative implementation of trait `std::marker::Send` for type `TestType<_>`:
   --> $DIR/coherence-conflicting-negative-trait-impl.rs:11:1
    |
 LL | unsafe impl<T: MyTrait + 'static> Send for TestType<T> {}
@@ -18,5 +18,5 @@ LL | unsafe impl<T: 'static> Send for TestType<T> {}
 
 error: aborting due to 2 previous errors
 
-Some errors have detailed explanations: E0119, E0748.
+Some errors have detailed explanations: E0119, E0751.
 For more information about an error, try `rustc --explain E0119`.

src/test/ui/issues/issue-33140-hack-boundaries.rs

@@ -23,7 +23,7 @@ trait Trait2 {}
 
 impl Trait2 for dyn Send {}
 impl !Trait2 for dyn Send {}
-//~^ ERROR E0748
+//~^ ERROR E0751
 
 // Problem 3: type parameter
 trait Trait3<T: ?Sized> {}

src/test/ui/issues/issue-33140-hack-boundaries.stderr

@@ -6,7 +6,7 @@ LL | impl Trait1 for dyn Send {}
 LL | impl Trait1 for dyn Send {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `(dyn std::marker::Send + 'static)`
 
-error[E0748]: found both positive and negative implementation of trait `Trait2` for type `(dyn std::marker::Send + 'static)`:
+error[E0751]: found both positive and negative implementation of trait `Trait2` for type `(dyn std::marker::Send + 'static)`:
   --> $DIR/issue-33140-hack-boundaries.rs:25:1
    |
 LL | impl Trait2 for dyn Send {}
@@ -64,5 +64,5 @@ LL | impl Trait5 for dyn Send where u32: Copy {}
 
 error: aborting due to 8 previous errors
 
-Some errors have detailed explanations: E0119, E0748.
+Some errors have detailed explanations: E0119, E0751.
 For more information about an error, try `rustc --explain E0119`.

src/test/ui/specialization/specialization-overlap-negative.rs

@@ -6,6 +6,6 @@ trait MyTrait {}
 struct TestType<T>(::std::marker::PhantomData<T>);
 
 unsafe impl<T: Clone> Send for TestType<T> {}
-impl<T: MyTrait> !Send for TestType<T> {} //~ ERROR E0748
+impl<T: MyTrait> !Send for TestType<T> {} //~ ERROR E0751
 
 fn main() {}

src/test/ui/specialization/specialization-overlap-negative.stderr

@@ -1,4 +1,4 @@
-error[E0748]: found both positive and negative implementation of trait `std::marker::Send` for type `TestType<_>`:
+error[E0751]: found both positive and negative implementation of trait `std::marker::Send` for type `TestType<_>`:
   --> $DIR/specialization-overlap-negative.rs:9:1
    |
 LL | unsafe impl<T: Clone> Send for TestType<T> {}
@@ -8,4 +8,4 @@ LL | impl<T: MyTrait> !Send for TestType<T> {}
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0748`.
+For more information about this error, try `rustc --explain E0751`.

src/test/ui/specialization/specialization-polarity.rs

@@ -7,11 +7,11 @@
 auto trait Foo {}
 
 impl<T> Foo for T {}
-impl !Foo for u8 {} //~ ERROR E0748
+impl !Foo for u8 {} //~ ERROR E0751
 
 auto trait Bar {}
 
 impl<T> !Bar for T {}
-impl Bar for u8 {} //~ ERROR E0748
+impl Bar for u8 {} //~ ERROR E0751
 
 fn main() {}

src/test/ui/specialization/specialization-polarity.stderr

@@ -1,4 +1,4 @@
-error[E0748]: found both positive and negative implementation of trait `Foo` for type `u8`:
+error[E0751]: found both positive and negative implementation of trait `Foo` for type `u8`:
   --> $DIR/specialization-polarity.rs:10:1
    |
 LL | impl<T> Foo for T {}
@@ -6,7 +6,7 @@ LL | impl<T> Foo for T {}
 LL | impl !Foo for u8 {}
    | ^^^^^^^^^^^^^^^^ negative implementation here
 
-error[E0748]: found both positive and negative implementation of trait `Bar` for type `u8`:
+error[E0751]: found both positive and negative implementation of trait `Bar` for type `u8`:
   --> $DIR/specialization-polarity.rs:15:1
    |
 LL | impl<T> !Bar for T {}
@@ -16,4 +16,4 @@ LL | impl Bar for u8 {}
 
 error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0748`.
+For more information about this error, try `rustc --explain E0751`.

src/test/ui/traits/negative-impls/negative-specializes-positive-item.rs

@@ -8,6 +8,6 @@ trait MyTrait {
 impl<T> MyTrait for T {
     default fn foo() {}
 }
-impl !MyTrait for u32 {} //~ ERROR E0748
+impl !MyTrait for u32 {} //~ ERROR E0751
 
 fn main() {}

src/test/ui/traits/negative-impls/negative-specializes-positive-item.stderr

@@ -1,4 +1,4 @@
-error[E0748]: found both positive and negative implementation of trait `MyTrait` for type `u32`:
+error[E0751]: found both positive and negative implementation of trait `MyTrait` for type `u32`:
   --> $DIR/negative-specializes-positive-item.rs:11:1
    |
 LL | impl<T> MyTrait for T {
@@ -9,4 +9,4 @@ LL | impl !MyTrait for u32 {}
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0748`.
+For more information about this error, try `rustc --explain E0751`.

src/test/ui/traits/negative-impls/negative-specializes-positive.rs

@@ -4,7 +4,7 @@
 // Negative impl for u32 cannot "specialize" the base impl.
 trait MyTrait {}
 impl<T> MyTrait for T {}
-impl !MyTrait for u32 {} //~ ERROR E0748
+impl !MyTrait for u32 {} //~ ERROR E0751
 
 // The second impl specializes the first, no error.
 trait MyTrait2 {}

src/test/ui/traits/negative-impls/negative-specializes-positive.stderr

@@ -1,4 +1,4 @@
-error[E0748]: found both positive and negative implementation of trait `MyTrait` for type `u32`:
+error[E0751]: found both positive and negative implementation of trait `MyTrait` for type `u32`:
   --> $DIR/negative-specializes-positive.rs:7:1
    |
 LL | impl<T> MyTrait for T {}
@@ -8,4 +8,4 @@ LL | impl !MyTrait for u32 {}
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0748`.
+For more information about this error, try `rustc --explain E0751`.

src/test/ui/traits/negative-impls/pin-unsound-issue-66544-clone.rs

@@ -5,7 +5,7 @@ use std::pin::Pin;
 struct MyType<'a>(Cell<Option<&'a mut MyType<'a>>>, PhantomPinned);
 
 impl<'a> Clone for &'a mut MyType<'a> {
-    //~^ ERROR E0748
+    //~^ ERROR E0751
     fn clone(&self) -> &'a mut MyType<'a> {
         self.0.replace(None).unwrap()
     }

src/test/ui/traits/negative-impls/pin-unsound-issue-66544-clone.stderr

@@ -1,4 +1,4 @@
-error[E0748]: found both positive and negative implementation of trait `std::clone::Clone` for type `&mut MyType<'_>`:
+error[E0751]: found both positive and negative implementation of trait `std::clone::Clone` for type `&mut MyType<'_>`:
   --> $DIR/pin-unsound-issue-66544-clone.rs:7:1
    |
 LL | impl<'a> Clone for &'a mut MyType<'a> {
@@ -8,4 +8,4 @@ LL | impl<'a> Clone for &'a mut MyType<'a> {
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0748`.
+For more information about this error, try `rustc --explain E0751`.

src/test/ui/traits/negative-impls/pin-unsound-issue-66544-derefmut.rs

@@ -10,7 +10,7 @@ use std::pin::Pin;
 struct MyType<'a>(Cell<Option<&'a mut MyType<'a>>>, PhantomPinned);
 
 impl<'a> DerefMut for &'a MyType<'a> {
-    //~^ ERROR E0748
+    //~^ ERROR E0751
     fn deref_mut(&mut self) -> &mut MyType<'a> {
         self.0.replace(None).unwrap()
     }

src/test/ui/traits/negative-impls/pin-unsound-issue-66544-derefmut.stderr

@@ -1,4 +1,4 @@
-error[E0748]: found both positive and negative implementation of trait `std::ops::DerefMut` for type `&MyType<'_>`:
+error[E0751]: found both positive and negative implementation of trait `std::ops::DerefMut` for type `&MyType<'_>`:
   --> $DIR/pin-unsound-issue-66544-derefmut.rs:12:1
    |
 LL | impl<'a> DerefMut for &'a MyType<'a> {
@@ -8,4 +8,4 @@ LL | impl<'a> DerefMut for &'a MyType<'a> {
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0748`.
+For more information about this error, try `rustc --explain E0751`.

src/test/ui/traits/negative-impls/positive-specializes-negative.rs

@@ -4,6 +4,6 @@
 trait MyTrait {}
 
 impl<T> !MyTrait for T {}
-impl MyTrait for u32 {} //~ ERROR E0748
+impl MyTrait for u32 {} //~ ERROR E0751
 
 fn main() {}

src/test/ui/traits/negative-impls/positive-specializes-negative.stderr

@@ -1,4 +1,4 @@
-error[E0748]: found both positive and negative implementation of trait `MyTrait` for type `u32`:
+error[E0751]: found both positive and negative implementation of trait `MyTrait` for type `u32`:
   --> $DIR/positive-specializes-negative.rs:7:1
    |
 LL | impl<T> !MyTrait for T {}
@@ -8,4 +8,4 @@ LL | impl MyTrait for u32 {}
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0748`.
+For more information about this error, try `rustc --explain E0751`.