Specialization Not Allowed for Deduced Parameter

[Yota via Digitalmars-d-learn]

On Friday, 22 August 2014 at 20:42:49 UTC, Yota wrote:
> Heya.  I'm working on a simple units-of-measure implementation 
> in DMD 2.066.0, and it doesn't seem to like the signature of my 
> '*' operator below.  I'm afraid I don't understand what the 
> error description is trying to tell me.  Here's a reduced case:

Same results for this simpler signature.

public struct UnitDef(string unitString) {
	auto opBinary(string op, string N)(UnitDef!N rhs)
	if (op == "*") {
		return UnitDef!(unitString ~ " " ~ N)();
	}
}