void main()
{
    int[int function(int)] aa1 = [x=>x:1, x=>x*2:2];
    foreach (k, v; aa1) {
        if (v == 1) assert(k(10) == 10);
        if (v == 2) assert(k(10) == 20);
    }

    int function(int)[int] aa2 = [1:x=>x, 2:x=>x*2];
    assert(aa2[1](10) == 10);
    assert(aa2[2](10) == 20);

    int n = 10;
    int[int delegate(int)] aa3 = [x=>n+x:1, x=>n+x*2:2];
    foreach (k, v; aa3) {
        if (v == 1) assert(k(10) == 20);
        if (v == 2) assert(k(10) == 30);
    }

    int delegate(int)[int] aa4 = [1:x=>n+x, 2:x=>n+x*2];
    assert(aa4[1](10) == 20);
    assert(aa4[2](10) == 30);
}