# `c_variadic` The tracking issue for this feature is: [#44930] [#44930]: https://github.com/rust-lang/rust/issues/44930 ------------------------ The `c_variadic` library feature exposes the `VaList` structure, Rust's analogue of C's `va_list` type. ## Examples ```rust #![feature(c_variadic)] use std::ffi::VaList; pub unsafe extern "C" fn vadd(n: usize, mut args: VaList) -> usize { let mut sum = 0; for _ in 0..n { sum += args.arg::(); } sum } ```