rust/tests/compile-fail/copy_null.rs

//error-pattern: invalid use of NULL pointer
#![feature(intrinsics)]

// Directly call intrinsic to avoid debug assertions in libstd
extern "rust-intrinsic" {
    fn copy_nonoverlapping<T>(src: *const T, dst: *mut T, count: usize);
}

fn main() {
    let mut data = [0u16; 4];
    let ptr = &mut data[0] as *mut u16;
    // Even copying 0 elements from NULL should error.
    unsafe { copy_nonoverlapping(std::ptr::null(), ptr, 0); }
}