cbindgen-0.24.5/tests/rust/std_lib.rs - cbindgen - Git at Google

 #[no_mangle]
 pub extern "C" fn root(
 	a: &Vec<String>,
     b: &Option<i32>,
     c: &Result<i32, String>
 ) { }
	#[no_mangle]
	pub extern "C" fn root(
	a: &Vec<String>,
	b: &Option<i32>,
	c: &Result<i32, String>
	) { }