rust/src/test/run-pass/vec-self-append.rs

use std;
import std::vec;

fn test_heap_to_heap() {
    // a spills onto the heap
    let a = [0, 1, 2, 3, 4];
    a += a;
    assert vec::len(a) == 10u;
    assert a[0] == 0;
    assert a[1] == 1;
    assert a[2] == 2;
    assert a[3] == 3;
    assert a[4] == 4;
    assert a[5] == 0;
    assert a[6] == 1;
    assert a[7] == 2;
    assert a[8] == 3;
    assert a[9] == 4;
}

fn test_stack_to_heap() {
    // a is entirely on the stack
    let a = [0, 1, 2];
    // a spills to the heap
    a += a;
    assert vec::len(a) == 6u;
    assert a[0] == 0;
    assert a[1] == 1;
    assert a[2] == 2;
    assert a[3] == 0;
    assert a[4] == 1;
    assert a[5] == 2;
}

fn test_loop() {
    // Make sure we properly handle repeated self-appends.
    let a: [int] = [0];
    let i = 20;
    let expected_len = 1u;
    while i > 0 {
        log_err vec::len(a);
        assert (vec::len(a) == expected_len);
        a += a;
        i -= 1;
        expected_len *= 2u;
    }
}

fn main() {
    test_heap_to_heap();
    test_stack_to_heap();
    test_loop();
}