Why doesn't alias this work with arrays?

[Andrej Mitrovic]

struct Wrap
{
    string wrap;
    alias wrap this;
}

void main()
{
    Wrap x;
    x = "foo";  // ok
    Wrap[] y = ["foo", "bar"];  // fail
}

Error: cannot implicitly convert expression (["foo","bar"]) of type
string[] to Wrap[]

Any special reason why this doesn't work? I hope it's just a bug or
unfinished implementation.