#![allow(dead_code, deprecated, unused_variables, unused_mut)]
#![feature(maybe_uninit_write_slice)]
fn main() {
    let mut vec = Vec::with_capacity(32);
    let src = [0; 16];
    vec.spare_capacity_mut()[..src.len()].write_copy_of_slice(&src);
    unsafe {
        vec.set_len(src.len());
    }
    assert_eq!(vec, src);
}