On Wednesday, 18 July 2018 at 17:30:21 UTC, Jonathan M Davis
wrote:
On Tuesday, July 17, 2018 21:18:12 John Colvin via
Digitalmars-d wrote:
Just do what std.typecons.Proxy does and return float.nan for
the incomparable case.
Since when is that legal? I thought that it was required for
opCmp to return int. Certainly, the spec implies that it has to
be int. The fact that the compiler allows it seems like a bug,
though if Phobos is doing it, it wouldn't surprise me if Walter
would choose to update the spec rather than fixing the compiler.
It always worked with float as returntype (at least since I'm
using D
- about 2.40 or so?), and it was necessary for the (unfortunately
deprecated) special operators <>, !<>, <>=, !<>=, ...
would really pissing me off if someone deemed this excellent
feature
beeing a bug and removed it. The OP already found out that some
valuable mathematical concepts doesn't work with only 3 values for
opCmp. The 4th value is essencial.
