Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 12 insertions, 0 deletions

diff --git a/compiler/rustc_error_codes/src/error_codes/E0751.md b/compiler/rustc_error_codes/src/error_codes/E0751.md
new file mode 100644
index 000000000..8794f7868
--- /dev/null
+++ b/compiler/rustc_error_codes/src/error_codes/E0751.md
@@ -0,0 +1,12 @@
+There are both a positive and negative trait implementation for the same type.
+
+Erroneous code example:
+
+```compile_fail,E0751
+trait MyTrait {}
+impl MyTrait for i32 { }
+impl !MyTrait for i32 { } // error!
+```
+
+Negative implementations are a promise that the trait will never be implemented
+for the given types. Therefore, both cannot exists at the same time.