Hopefully not-too-obvious observation

[Jerry]

Hi folks,

I was looking at writing a hash-like class with a specific operator and
disliking the syntax of:

T opBinary(string op)(U key) if (op == "in") {}

When it occurred to me that it could be simply tightened up as:

T opBinary(string op : "in")(U key) {}

Any thoughts?  Is this bad style?

Thanks
Jerry