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# Error code E0743

The C-variadic type `...` has been nested inside another type.

Erroneous code example:

    #![allow(unused)]
    fn main() {
    fn foo2(x: u8, y: &...) {} // error!
    }

Only foreign functions can use the C-variadic type (`...`). In such functions, `...` may only occur non-nested. That is, `y: &'a ...` is not allowed.

A C-variadic type is used to give an undefined number of parameters to a given function (like `printf` in C). The equivalent in Rust would be to use macros directly (like `println!` for example).