import std.stdio;

class Foo
{
  int[string] vals;

  Foo opIndexAssign(int val, string key)
  {
    writefln("Got key %s", key);
    vals[key] = val;
    return this;
  }
}

Foo foo;

void main()
{
  foo = new Foo;
  foo["lol"] = 5;
  writefln("%d", foo.vals["lol"]);
}