ABI SINGLETION

This is a simple ABI singleton Trait helper crate. When you need a trait that only one implementation can exist, you can use this crate.

Usage

use abi_singleton::{api_impl, api_trait};

#[repr(C)]
pub struct Food {
    pub count: usize,
}

/// Trait definition:
#[allow(unused)]
#[api_trait]
trait Cat {
    unsafe fn eat(food: Food) -> usize;
}

/// Trait Implementation:
#[allow(unused)]
struct CatReal;

/// Function Implementation:
#[api_impl]
impl Cat for CatReal {
    unsafe fn eat(food: Food) -> usize {
        food.count
    }
}


// Use the trait:
// `[trait]Impl` is auto generated.
let count = unsafe { CatImpl::eat(Food { count: 3 }) };

Limitations

Only C FFI func support, self fields are not supported.