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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
commit | 698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch) | |
tree | 173a775858bd501c378080a10dca74132f05bc50 /library/core/src/ffi/c_void.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 'library/core/src/ffi/c_void.md')
-rw-r--r-- | library/core/src/ffi/c_void.md | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/library/core/src/ffi/c_void.md b/library/core/src/ffi/c_void.md new file mode 100644 index 000000000..ee7403aa0 --- /dev/null +++ b/library/core/src/ffi/c_void.md @@ -0,0 +1,16 @@ +Equivalent to C's `void` type when used as a [pointer]. + +In essence, `*const c_void` is equivalent to C's `const void*` +and `*mut c_void` is equivalent to C's `void*`. That said, this is +*not* the same as C's `void` return type, which is Rust's `()` type. + +To model pointers to opaque types in FFI, until `extern type` is +stabilized, it is recommended to use a newtype wrapper around an empty +byte array. See the [Nomicon] for details. + +One could use `std::os::raw::c_void` if they want to support old Rust +compiler down to 1.1.0. After Rust 1.30.0, it was re-exported by +this definition. For more information, please read [RFC 2521]. + +[Nomicon]: https://doc.rust-lang.org/nomicon/ffi.html#representing-opaque-structs +[RFC 2521]: https://github.com/rust-lang/rfcs/blob/master/text/2521-c_void-reunification.md |