On Saturday, 8 December 2018 at 14:21:01 UTC, Paul Backus wrote:
On Saturday, 8 December 2018 at 09:57:29 UTC, aliak wrote:
This compiles fine. However, if I change the match template to:
template match(handlers...) {
auto match(alias f)(Holder!f holder) {
return handlers[0](holder);
}
}
Notice the template parameter of the eponymous match is an
alias now, and the function parameter is typed as a Holder.
The "de-sugared" version of your second `match` function looks
like this:
template match(handlers...) {
template match(alias f) {
auto match(Holder!f holder) {
return handlers[0](holder);
}
}
}
Notice the second template nested inside the first. That's the
"non-gloal template" the error is complaining about.
Ah, that's a good way of breaking it down. But ok, so then the
other version would be lowered to:
template match(handlers...) {
template match(T) {
auto match(T holder) {
return handlers[0](holder);
}
}
}
So now the second template is accessing a T, which is actually a
Holder!f right? But doing that makes it "work". Even though the
number of "contexts" needed to execute "handlers[0](holder)" is
the same, right?
