Show AAs in all their virtues

[via Digitalmars-d]

I believe we should show off D in all its virtue

at http://dlang.org/hash-map.html

by addition to

    int* p = ("hello" in aa);
    if (p !is null) {}

also include the even compacter

    if (auto p = "hello" in aa) {}

along with

    if (const p = "hello" in aa) {}

in the non-mutating case.

Destroy!