So I keep finding myself in a situation where I need to use an alias template arg, but what I actually want to alias is a MEMBER of some symbol, or even a function local.
struct MyStruct
{
int x;
}
template Thing(alias t)
{
...
}
MyStruct s;
Thing!(s); // this is fine
Thing!(s.x); // this doesn't work
This seems like it should work intuitively, I was very surprised when it didn't. 's.x' can be resolved just as easily as 's' at compile time, but Walter said 'alias' could only understand absolute symbols, not symbol + offset.
Has anyone else run into this? What's the reason for the restriction?
I've also found I need to do this on a number of occasions: template Thing(alias T...)
Ie, receive an unknown number of aliases... But that doesn't work either.