fn allocate_byte_array(len: usize) -> Vec<u8> {
	let mut v: Vec<u8> = Vec::with_capacity(len);
	unsafe {
		v.set_len(len);
	}
	v
}

fn main() {
    let v = allocate_byte_array(1024*1024*1024*100);
    print!("size {}", v.len());
}