1 The C-variadic type `...` has been nested inside another type.
3 Erroneous code example:
6 fn foo2(x: u8, y: &...) {} // error!
9 Only foreign functions can use the C-variadic type (`...`). In such functions,
10 `...` may only occur non-nested. That is, `y: &'a ...` is not allowed.
12 A C-variadic type is used to give an undefined number of parameters to a given
13 function (like `printf` in C). The equivalent in Rust would be to use macros
14 directly (like `println!` for example).