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Stabilize unsafe extern blocks #313

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Merged
merged 3 commits into from
Aug 6, 2024
Merged

Stabilize unsafe extern blocks #313

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0e043ba
Stabilize unsafe extern blocks
spastorino Jul 18, 2024
c320aa4
Capitalize the "unsafe" in "unsafe extern"
traviscross Jul 21, 2024
f646cd4
Fill in version that `unsafe extern` will stabilize
traviscross Aug 6, 2024
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2 changes: 1 addition & 1 deletion src/SUMMARY.md
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- [`gen` keyword](rust-2024/gen-keyword.md)
- [Macro fragment specifiers](rust-2024/macro-fragment-specifiers.md)
- [Never type fallback change](rust-2024/never-type-fallback.md)
- [`unsafe extern` blocks](rust-2024/unsafe-extern.md)
- [Unsafe `extern` blocks](rust-2024/unsafe-extern.md)
- [Unsafe attributes](rust-2024/unsafe-attributes.md)
6 changes: 2 additions & 4 deletions src/rust-2024/unsafe-extern.md
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# `unsafe extern` blocks
# Unsafe `extern` blocks

🚧 The 2024 Edition has not yet been released and hence this section is still "under construction".
More information may be found in the tracking issue at <https://github.com/rust-lang/rust/issues/123743>.
Expand All @@ -11,13 +11,11 @@ More information may be found in the tracking issue at <https://github.com/rust-

## Details

Rust 1.xx <!--TODO--> added the ability in all editions to mark [`extern` blocks] with the `unsafe` keyword.[^RFC3484] Adding the `unsafe` keyword helps to emphasize that it is the responsibility of the author of the `extern` block to ensure that the signatures are correct. If the signatures are not correct, then it may result in undefined behavior.
Rust 1.82 added the ability in all editions to mark [`extern` blocks] with the `unsafe` keyword.[^RFC3484] Adding the `unsafe` keyword helps to emphasize that it is the responsibility of the author of the `extern` block to ensure that the signatures are correct. If the signatures are not correct, then it may result in undefined behavior.

The syntax for an unsafe `extern` block looks like this:

```rust
# #![feature(unsafe_extern_blocks)]

unsafe extern "C" {
// sqrt (from libm) may be called with any `f64`
pub safe fn sqrt(x: f64) -> f64;
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