#![allow(unused_variables)]
#![feature(allocator_api)]
fn main() {
    use std::alloc::System;
    let mut vec = Vec::with_capacity_in(10, System);
    assert_eq!(vec.len(), 0);
    assert!(vec.capacity() >= 10);
    for i in 0..10 {
        vec.push(i);
    }
    assert_eq!(vec.len(), 10);
    assert!(vec.capacity() >= 10);
    vec.push(11);
    assert_eq!(vec.len(), 11);
    assert!(vec.capacity() >= 11);
    let vec_units = Vec::<(), System>::with_capacity_in(10, System);
    assert_eq!(vec_units.capacity(), usize::MAX);
}