Module blog::daily_rfcs::ffi::_2137_variadic

Support defining C-compatible variadic functions in Rust.

Note

Variadic fucntion declaration:

pub unsafe extern "C" fn foo(arg: T, arg2: T2, args: ...);

1. The use of ... as the type of args at the end of the argument list declares the function foo as variadic function.
2. args: ... must apears as the last argument of the function, and there must be at least one argument before it.
3. The function must be extern "C" and unsafe.
4. The real type of args is core::intrinsics::VaList<'a>, the lifetme 'a prevents the arguments from outliving the variadic function.

RFC: 2137-variadic