On Monday, 2 May 2022 at 16:29:05 UTC, Loara wrote:
On Sunday, 1 May 2022 at 03:57:12 UTC, Elfstone 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
simp( cast(MyAlias!string) 4);//Also invalid since
MyAlias!string is exactly int
simp!string(4);//Ok, no parameter deduction
}
```
Instead to use aliases it's better (both in D and in C++) to
use constraints/concepts.
Yeah, I understand some cases are impossible, and to be avoided.
I believe your example is also impossible in C++, but it's better
the compiler do its job when it's totally possible - needless to
say, C++ compilers can deduce my _dot_.
Constraints/Concepts are useful, but what's needed here is a
literal _alias_. There's no ambiguity, no extra template
parameters introduced in the declaration.
