Error code E0045

Variadic parameters have been used on a non-C ABI function.

Erroneous code example:

#![allow(unused)] fn main() { extern "Rust" { fn foo(x: u8, ...); // error! } }

Rust only supports variadic parameters for interoperability with C code in its FFI. As such, variadic parameters can only be used with functions which are using the C ABI. To fix such code, put them in an extern "C" block:

#![allow(unused)] fn main() { extern "C" { fn foo (x: u8, ...); } }