I think you need to find a better example, as I can write a superior
version with existing C++20 tools:

```
template<std::integral T>
  requires is_one_of<T, std::uint8_t, std::uint64_t>
void my_func(T param)
{
  ...
}
```

This has the advantage of making it clear *in the interface* of the
function what is required, rather than being an implementation detail
that might not be seen by the user.

Can you provide use cases that aren't better written as concepts?