On Saturday, 21 April 2018 at 11:23:33 UTC, Alex wrote:
On Thursday, 19 April 2018 at 17:55:47 UTC, Simen Kjærås wrote:
Your first example defines two templates (which are overloads
of the same name), the second only one. There's no ambiguity
there.
So, do you mean, that the constraint belongs to the interface
of a template?
Not necessarily - it depends on what you want to achieve. The
only thing I mean is that the code clearly defines two templates
in one case (and chooses which template to instantiate based on
the arguments), and one template in the other (and chooses the
contents of that template based on the arguments). Sure, the end
result may be similar*, but how it works in the language is
clearly defined, and different between the two cases.
*In this case, there are important differences - in the first
case the template itself is marked with a UDA, in the second the
enum member is. In the first case foo!"c" will fail to
instantiate, in the second it won't.
--
Simen
