diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
commit | 698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch) | |
tree | 173a775858bd501c378080a10dca74132f05bc50 /compiler/rustc_error_codes/src/error_codes/E0303.md | |
parent | Initial commit. (diff) | |
download | rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip |
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'compiler/rustc_error_codes/src/error_codes/E0303.md')
-rw-r--r-- | compiler/rustc_error_codes/src/error_codes/E0303.md | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/compiler/rustc_error_codes/src/error_codes/E0303.md b/compiler/rustc_error_codes/src/error_codes/E0303.md new file mode 100644 index 000000000..459906047 --- /dev/null +++ b/compiler/rustc_error_codes/src/error_codes/E0303.md @@ -0,0 +1,38 @@ +#### Note: this error code is no longer emitted by the compiler. + +Sub-bindings, e.g. `ref x @ Some(ref y)` are now allowed under +`#![feature(bindings_after_at)]` and checked to make sure that +memory safety is upheld. + +-------------- + +In certain cases it is possible for sub-bindings to violate memory safety. +Updates to the borrow checker in a future version of Rust may remove this +restriction, but for now patterns must be rewritten without sub-bindings. + +Before: + +```compile_fail +match Some("hi".to_string()) { + ref op_string_ref @ Some(s) => {}, + None => {}, +} +``` + +After: + +``` +match Some("hi".to_string()) { + Some(ref s) => { + let op_string_ref = &Some(s); + // ... + }, + None => {}, +} +``` + +The `op_string_ref` binding has type `&Option<&String>` in both cases. + +See also [Issue 14587][issue-14587]. + +[issue-14587]: https://github.com/rust-lang/rust/issues/14587 |