fn test_stack_assign() {
    let s: ~str = ~"a";
    log(debug, s);
    let t: ~str = ~"a";
    assert (s == t);
    let u: ~str = ~"b";
    assert (s != u);
}

fn test_heap_lit() { ~"a big string"; }

fn test_heap_assign() {
    let s: ~str = ~"a big ol' string";
    let t: ~str = ~"a big ol' string";
    assert (s == t);
    let u: ~str = ~"a bad ol' string";
    assert (s != u);
}

fn test_heap_log() { let s = ~"a big ol' string"; log(debug, s); }

fn test_stack_add() {
    assert (~"a" + ~"b" == ~"ab");
    let s: ~str = ~"a";
    assert (s + s == ~"aa");
    assert (~"" + ~"" == ~"");
}

fn test_stack_heap_add() { assert (~"a" + ~"bracadabra" == ~"abracadabra"); }

fn test_heap_add() {
    assert (~"this should" + ~" totally work" == ~"this should totally work");
}

fn test_append() {
    let mut s = ~"";
    s += ~"a";
    assert (s == ~"a");

    let mut s = ~"a";
    s += ~"b";
    log(debug, s);
    assert (s == ~"ab");

    let mut s = ~"c";
    s += ~"offee";
    assert (s == ~"coffee");

    s += ~"&tea";
    assert (s == ~"coffee&tea");
}

fn main() {
    test_stack_assign();
    test_heap_lit();
    test_heap_assign();
    test_heap_log();
    test_stack_add();
    test_stack_heap_add();
    test_heap_add();
    test_append();
}