On Wednesday, 30 March 2016 at 18:56:29 UTC, H. S. Teoh wrote:
Does this do what you want?
Okay, I've looked at this a bit more thoroughly and it works perfectly (perhaps with a better name put in phobos?).
If I'm understanding this correctly, the ImplType creates the correct type signature for the output and then conditionalOnly puts the right value in.
One thing that is confusing is that when I create a new function that adjusts conditionalOnly to just return y instead of fun(y), then I get an error about returning a tuple. I'm like, where did I use a tuple. I guess related to
https://issues.dlang.org/show_bug.cgi?id=15436
