Difference between "can call" and "can compile"

[FeepingCreature]

On Monday, 7 September 2020 at 14:57:24 UTC, Steven Schveighoffer 
wrote:
> I was wondering, would it be a useful addition to have a way to 
> say "can call" instead of "can compile"? In other words, this 
> has a valid template IFTI match, regardless of whether it 
> compiles or not. In which case, you can distinguish mismatch 
> errors from implementation errors.
>
> Thoughts?
>
> -Steve

Yes yes yes yes yes *yes yes*!

Please!!!!!

This would make template errors so unbelievably much better.