https://github.com/sharksforarms/variyak

macro to call variadic functions using data from a container
https://github.com/sharksforarms/variyak

rust-macro variadic

Last synced: 4 months ago
JSON representation

macro to call variadic functions using data from a container

• Host: GitHub
• URL: https://github.com/sharksforarms/variyak
• Owner: sharksforarms
• License: apache-2.0
• Created: 2021-03-11T14:23:43.000Z (almost 5 years ago)
• Default Branch: main
• Last Pushed: 2021-04-06T19:01:00.000Z (almost 5 years ago)
• Last Synced: 2025-08-23T18:21:37.600Z (6 months ago)
• Topics: rust-macro, variadic
• Language: Rust
• Homepage:
• Size: 17.6 KB
• Stars: 1
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE-APACHE
  • Code of conduct: CODE_OF_CONDUCT.md

Awesome Lists containing this project

README

          
# Variyak

[![Latest Version](https://img.shields.io/crates/v/variyak.svg)](https://crates.io/crates/variyak)

[![Rust Documentation](https://docs.rs/variyak/badge.svg)](https://docs.rs/variyak)

[![Actions Status](https://github.com/sharksforarms/variyak/workflows/CI/badge.svg)](https://github.com/sharksforarms/variyak/actions)

This crate provides a macro `call_variadic` which can be used to construct boilerplate code

to call variadic functions using data from a container such as a Vec.

Example:

```rust

#![feature(c_variadic)]

use variyak::call_variadic;

fn main() {

    let data = vec![1, 2];

    let arg = 0;

    mod test {

        #[no_mangle]

        pub unsafe extern "C" fn my_func(_fixed: u32, mut _args: ...) -> bool {

            true

        }

    }

    unsafe {

        assert!(call_variadic!(

            test::my_func(arg, ...)   // function to call, `...` is the variadic arguments

            data,                     // container identifier

            n,                        // index identifier

            data[n],                  // argument expression: get `argument` at index `n`

            2,                        // maximum number of arguments to expand

        ));

    }

    unsafe {

        use test::my_func;

        assert!(call_variadic!(my_func(arg, ...), data, n, data[n], 2));

        assert!(call_variadic!(my_func(arg, ...), data, n, data[n], 2));

        assert!(call_variadic!(my_func(arg, arg, ..., arg), data, n, data[n], 2));

        assert!(call_variadic!(my_func(arg, ..., arg), data, n, data[n], 2));

        assert!(call_variadic!(my_func(arg, 42 + 27, ..., arg, 10usize), data, n, data[n], 2));

    };

}

```