rust/rustc_feature at a2dcb3a6d9aead3964b3b1cdf814dc7eb9c5d8ed - rust

History

bors 63d16b5a98 Auto merge of #117472 - jmillikin:stable-c-str-literals, r=Nilstrieb Stabilize C string literals RFC: https://rust-lang.github.io/rfcs/3348-c-str-literal.html Tracking issue: https://github.com/rust-lang/rust/issues/105723 Documentation PR (reference manual): https://github.com/rust-lang/reference/pull/1423 # Stabilization report Stabilizes C string and raw C string literals (`c"..."` and `cr#"..."#`), which are expressions of type [`&CStr`](https://doc.rust-lang.org/stable/core/ffi/struct.CStr.html). Both new literals require Rust edition 2021 or later. ```rust const HELLO: &core::ffi::CStr = c"Hello, world!"; ``` C strings may contain any byte other than `NUL` (`b'\x00'`), and their in-memory representation is guaranteed to end with `NUL`. ## Implementation Originally implemented by PR https://github.com/rust-lang/rust/pull/108801, which was reverted due to unintentional changes to lexer behavior in Rust editions < 2021. The current implementation landed in PR https://github.com/rust-lang/rust/pull/113476, which restricts C string literals to Rust edition >= 2021. ## Resolutions to open questions from the RFC * Adding C character literals (`c'.'`) of type `c_char` is not part of this feature. * Support for `c"..."` literals does not prevent `c'.'` literals from being added in the future. * C string literals should not be blocked on making `&CStr` a thin pointer. * It's possible to declare constant expressions of type `&'static CStr` in stable Rust (as of v1.59), so C string literals are not adding additional coupling on the internal representation of `CStr`. * The unstable `concat_bytes!` macro should not accept `c"..."` literals. * C strings have two equally valid `&[u8]` representations (with or without terminal `NUL`), so allowing them to be used in `concat_bytes!` would be ambiguous. * Adding a type to represent C strings containing valid UTF-8 is not part of this feature. * Support for a hypothetical `&Utf8CStr` may be explored in the future, should such a type be added to Rust.	2023-12-01 13:33:55 +00:00
..
src	Auto merge of #117472 - jmillikin:stable-c-str-literals, r=Nilstrieb	2023-12-01 13:33:55 +00:00
Cargo.toml	Clean up `rustc_*/Cargo.toml`.	2023-10-30 08:46:02 +11:00

bors 63d16b5a98 Auto merge of #117472 - jmillikin:stable-c-str-literals, r=Nilstrieb

Stabilize C string literals

RFC: https://rust-lang.github.io/rfcs/3348-c-str-literal.html

Tracking issue: https://github.com/rust-lang/rust/issues/105723

Documentation PR (reference manual): https://github.com/rust-lang/reference/pull/1423

# Stabilization report

Stabilizes C string and raw C string literals (`c"..."` and `cr#"..."#`), which are expressions of type [`&CStr`](https://doc.rust-lang.org/stable/core/ffi/struct.CStr.html). Both new literals require Rust edition 2021 or later.

```rust
const HELLO: &core::ffi::CStr = c"Hello, world!";
```

C strings may contain any byte other than `NUL` (`b'\x00'`), and their in-memory representation is guaranteed to end with `NUL`.

## Implementation

Originally implemented by PR https://github.com/rust-lang/rust/pull/108801, which was reverted due to unintentional changes to lexer behavior in Rust editions < 2021.

The current implementation landed in PR https://github.com/rust-lang/rust/pull/113476, which restricts C string literals to Rust edition >= 2021.

## Resolutions to open questions from the RFC

* Adding C character literals (`c'.'`) of type `c_char` is not part of this feature.
  * Support for `c"..."` literals does not prevent `c'.'` literals from being added in the future.
* C string literals should not be blocked on making `&CStr` a thin pointer.
  * It's possible to declare constant expressions of type `&'static CStr` in stable Rust (as of v1.59), so C string literals are not adding additional coupling on the internal representation of `CStr`.
* The unstable `concat_bytes!` macro should not accept `c"..."` literals.
  * C strings have two equally valid `&[u8]` representations (with or without terminal `NUL`), so allowing them to be used in `concat_bytes!` would be ambiguous.
* Adding a type to represent C strings containing valid UTF-8 is not part of this feature.
  * Support for a hypothetical `&Utf8CStr` may be explored in the future, should such a type be added to Rust.

2023-12-01 13:33:55 +00:00

src

Auto merge of #117472 - jmillikin:stable-c-str-literals, r=Nilstrieb

2023-12-01 13:33:55 +00:00

Cargo.toml

Clean up `rustc_*/Cargo.toml`.

2023-10-30 08:46:02 +11:00