async-ffi: FFI-compatible futures

Convert your Rust Futures into a FFI-compatible struct without relying unstable Rust ABI and struct layout. Easily provide async functions in dynamic library maybe compiled with different Rust than the invoker.

Provide some async functions in library: (plugin side) ``rust // Compile withcrate-type = ["cdylib"]`. use async_ffi::{FfiFuture, FutureExt};

[no_mangle]

pub extern "C" fn work(arg: u32) -> FfiFuture { async move { let ret = dosomeio(arg).await; dosomesleep(42).await; ret } .into_ffi() } ```

Execute async functions from external library: (host or executor side) ```rust use async_ffi::{FfiFuture, FutureExt};

extern "C" { #[no_mangle] fn work(arg: u32) -> FfiFuture; }

async fn run_work(arg: u32) -> u32 { unsafe { work(arg).await } } ```