On Thursday, 5 December 2013 at 13:55:30 UTC, Martin Nowak wrote:
Ah well, this was a question for ideas.
I don't really know to get there.
I can think of a few things:
1. The compiler could mark what made it reject a candidate. If it
failed due to a template constraint it could flag the last
evaluated condition. If the constraint passed, it could flag the
arguments whose types did not match. Flagging could be with a
special symbol. An IDE could use a different font, colors, bold
etc.
2. If a constraint is a function requirement rather than a
condition for matching, it could be replaced with a static assert.
3. It may be possible to embed constraints into a type
specification. It might not help a lot, but may make it easier
for people to parse the description easier.
4. I frequently think a lot of this constraint stuff could be
done in some kind if cascading if then else style. I'm not sure
how a failure would be reported, but it could greatly reduce the
number of constraints.
