C-style enums in FFI (and a proposal to lump in with unions)

retep998 · October 7, 2015, 6:45pm

Currently I get around the issue of the lack of C unions, C bitflags, C enums, and even C bitfields by using my own custom macros in winapi.

github.com

retep998/winapi-rs/blob/master/src/macros.rs

// Copyright © 2015-2017 winapi-rs developers
// Licensed under the Apache License, Version 2.0
// <LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
// All files in the project carrying such notice may not be copied, modified, or distributed
// except according to those terms.
//! Macros to make things easier to define
macro_rules! DECLARE_HANDLE {
    ($name:ident, $inner:ident) => {
        pub enum $inner {}
        pub type $name = *mut $inner;
    };
}
macro_rules! MAKE_HRESULT {
    ($sev:expr, $fac:expr, $code:expr) => {
        ($sev << 31) | ($fac << 16) | $code
    }
}
macro_rules! MAKE_SCODE {
    ($sev:expr, $fac:expr, $code:expr) => {

This file has been truncated. show original

Also note that #[repr(C)] for enums is wrong since it will try to fit the discriminant in a usize or isize while on Windows enums are always 32-bit

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C-style enums in FFI (and a proposal to lump in with unions)

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