// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

// compile-flags: -C debug-assertions

use std::slice;

pub fn main() {
    // In a slice of zero-size elements the pointer is meaningless.
    // Ensure iteration still works even if the pointer is at the end of the address space.
    let slice: &[()] = unsafe { slice::from_raw_parts(-5isize as *const (), 10) };
    assert_eq!(slice.len(), 10);
    assert_eq!(slice.iter().count(), 10);

    // .nth() on the iterator should also behave correctly
    let mut it = slice.iter();
    assert!(it.nth(5).is_some());
    assert_eq!(it.count(), 4);

    let slice: &mut [()] = unsafe { slice::from_raw_parts_mut(-5isize as *mut (), 10) };
    assert_eq!(slice.len(), 10);
    assert_eq!(slice.iter_mut().count(), 10);

    let mut it = slice.iter_mut();
    assert!(it.nth(5).is_some());
    assert_eq!(it.count(), 4);
}