src/tools/rustfmt/tests/target/issue_4528.rs

#![allow(clippy::no_effect)]

extern "C" {
    // N.B., mutability can be easily incorrect in FFI calls -- as
    // in C, the default is mutable pointers.
    fn ffi(c: *mut u8);
    fn int_ffi(c: *mut i32);
}