bors c70b35efd8 Auto merge of #84267 - dtolnay:ptrunit, r=nagisa ... Make *const (), *mut () okay for FFI Pointer-to-() is used occasionally in the standard library to mean "pointer to none-of-your-business". Examples: - `RawWakerVTable::new` https://doc.rust-lang.org/1.51.0/std/task/struct.RawWakerVTable.html#method.new - `<*const T>::to_raw_parts` https://doc.rust-lang.org/nightly/std/primitive.pointer.html#method.to_raw_parts I believe it's useful for the same purpose in FFI signatures, even while `()` itself is not FFI safe. The following should be allowed: ```rust extern "C" { fn demo(pc: *const (), pm: *mut ()); } ``` Prior to this PR, those pointers were not considered okay for an extern signature. ```console warning: `extern` block uses type `()`, which is not FFI-safe --> src/main.rs:2:17 | 2 | fn demo(pc: *const (), pm: *mut ()); | ^^^^^^^^^ not FFI-safe | = note: `#[warn(improper_ctypes)]` on by default = help: consider using a struct instead = note: tuples have unspecified layout warning: `extern` block uses type `()`, which is not FFI-safe --> src/main.rs:2:32 | 2 | fn demo(pc: *const (), pm: *mut ()); | ^^^^^^^ not FFI-safe | = help: consider using a struct instead = note: tuples have unspecified layout ```		2021-10-03 00:41:49 +00:00
..
src	Auto merge of #84267 - dtolnay:ptrunit, r=nagisa	2021-10-03 00:41:49 +00:00
Cargo.toml	Migrate to 2021	2021-09-20 22:21:42 -04:00