Hauleth:
Is there any reason to allow overload `op=`? IMHO it should be left illegal and should be interpreted always as `a = a op b`. It will be simpler and less confusing.
The increase of complexity and confusion is small.
Also why `opEquals` is independent from `opCmp`?
A Complex number defines equality but not comparisons: https://raw.github.com/D-Programming-Language/phobos/master/std/complex.d Sometimes computing equality is faster than comparisons, so better have both.
Once again `opEquals` should be removed and equality will be provided by `opCmp() == 0`.
I'd like the opposite: more freedom to be able to define "<" but not "<=". Bye, bearophile
