On Monday, 2 May 2022 at 16:29:05 UTC, Loara wrote:
Template deduction for aliased function parameter is a very
tricky argument and it's not so simple to handle in certain
cases. Consider for example this code:
```d
template MyAlias(T){
alias MyAlias = int;
}
T simp(T)(MyAlias!T val){
return T.init;
}
int main(){
simp(3);//Impossible to deduce T
Why? That's the issue. It is very possible to deduce T here.
Compiler just isn't trying. The function takes an int. Doesn't
take a rocket scientist to figure that one out.
simp( cast(MyAlias!string) 4);//Also invalid since
MyAlias!string is exactly int
Yes, invalid, as well it should be.
simp!string(4);//Ok, no parameter deduction
}
```
No issue here.
Instead to use aliases it's better (both in D and in C++) to
use constraints/concepts.
No. It *would* be better if compiler didn't play stupid here. I
shouldn't have to write 50+ more lines boilerplate for what the
compiler should be able to figure out. I might as well forego the
templates and just write explicit overloads. At which point I
would question why use templates at all.
