> like have a type error in a branch that in the current specialization is never executed doesn't count as a type error
I’ve struggled with my feelings on this even to the extent that C++ allows it, because while it is flexible, it can also hide errors in libraries that will only blow up when used in very specific ways.
Yes, that is a downside, but when you write very generic code being limited in what code you can write because it has to typecheck even for types that it doesn't apply to is one of the more frustrating things of doing this in C++ and other languages.
I’ve struggled with my feelings on this even to the extent that C++ allows it, because while it is flexible, it can also hide errors in libraries that will only blow up when used in very specific ways.