C++ enum to its value

[aben20807]

https://stackoverflow.com/questions/8357240/how-to-automatically-convert-strongly-typed-enum-into-int/33083231#33083231
https://godbolt.org/z/nvaxW5a74

#include <type_traits>

enum Color {
    Red,
    Green,
    Blue,
};

template <typename E>
constexpr auto to_underlying(E e) noexcept {
    return static_cast<std::underlying_type_t<E>>(e);
}

int main() {
    Color c = Green;
    int c_int = to_underlying(c);
    return c_int;
}