main()1fn main() { 2 extern "C" { 3 // Use the wrong type(ie. not the pointer width) for the `size` 4 // argument. 5 #[cfg(target_pointer_width="64")] 6 fn malloc(size: u32) -> *mut std::ffi::c_void; 7 8 #[cfg(target_pointer_width="32")] 9 fn malloc(size: u16) -> *mut std::ffi::c_void; 10 } 11 12 unsafe { 13 let _p1 = malloc(42); //~ ERROR Undefined Behavior: scalar size mismatch 14 }; 15 } 16