On Sunday, 3 May 2015 at 18:54:45 UTC, Andrei Alexandrescu wrote:
You're right, that is lovely! I've improved it as follows:
mixin template forwardToMember(alias member, methods...)
{
import std.algorithm : among;
import std.traits : ParameterTypeTuple;
template opDispatch(string sym)
if ((methods.length == 0 || sym.among(methods)))
{
auto ref opDispatch(
ParameterTypeTuple!(__traits(getMember, member,
sym)) args)
{
return __traits(getMember, member, sym)(args);
}
}
}
So now ref returns are preserved and the mixin is
self-contained (doesn't require imports from the outside).
Compared to my solution, this has the advantage that if the
child defines a method, it will take precedence over the
formatted one. So that allowed me to add a feature: if no
methods are specified, all are forwarded.
There are a couple of ways in which this could and should be
improved, most notably overloads control. Even as is it's
pretty darn awesome, Meta could you please make it into a pull
request? I think it should go in std.functional.
Andrei
I have forgotten to mention that I will make a pull request for
this ASAP. I have been in the process of moving and starting a
new job this week and last so I only have enough time to
occasionally post currently.
