I was implying a compile-time solution, i.e. where the result of the mapping is constexpr. On second though, maybe it can be done at compile time, with this: h

I was implying a compile-time solution, i.e. where the result of the mapping is constexpr. On second though, maybe it can be done at compile time, with this: http://b.atch.se/posts/constexpr-counter/ http://b.atch.se/posts/constexpr-counter/