Peter Dimov

`mp_enum` would just be `std::integral_constant`, so there's not that much gain for supplying the alias. (`mp_int` is also just `std::integral_constant`, but saves more typing.) I could have used `integral_constant` in...

Is this supposed to return a "view" into the original tuple, instead of a copy?

If we return to this one, while we're at it, a view makes sense, but in this case I'd prefer if the function has `view` in the name. How about...

`mp_identity` is often what you want, but not always; when the list contains integral constants, you don't want them wrapped. I went back and forth on adding the `mp_identity` a...

Looks like a GCC bug. I'll try to figure out why it happens. Here's a workaround: ``` template using enum_ = std::integral_constant; ```

> Interestingly, if I comment out line 22 and 23 as Commenting out line 22 (`Foo::A1`) is enough. It looks like GCC doesn't take into account the type of `EnumVal`,...

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104867

While types derived from `mpl::vector` and `fusion::vector` are also MPL sequences (whether accidentally or by design, I'm not quite sure), types derived from `mp_list` aren't. See f.ex. https://godbolt.org/z/71sGzP4zj. Only `mp_list`...

Would you mind giving me an example of `mp_make_identity` being used?

Building with both 2 and 3 in a single run was certainly intended to be supported, and breaking it is no good.