Vector.this

{
    Vector!(int, 6) vec = null;
    assert(vec.empty);
}

{
    Vector!(int, 6) vec = Vector!(int, 6).build(1, 2);
    assert(vec == [1, 2]);
}

{
    auto tmp = Vector!(int, 6).build(1, 2);
    Vector!(int, 6) vec = tmp;
    assert(vec == [1, 2]);
}


{
    Vector!(int, 6) vec = Vector!(int, 4).build(1, 2);
    assert(vec == [1, 2]);
}

{
    auto tmp = Vector!(int, 4).build(1, 2);
    Vector!(int, 6) vec = tmp;
    assert(vec == [1, 2]);
}

{
    int[3] tmp = [1, 2, 3];
    Vector!(int, 6) vec = tmp[];
    assert(vec == [1, 2, 3]);
}

{
    struct Range{
        int i;

        bool empty()(){return i == 0;}
        int front()(){return i;}
        void popFront()(){i -= 1;}
        //size_t length(); //no length
    }

    Vector!(int, 6) vec = Range(3);
    assert(vec == [3, 2, 1]);
}