C++ constexpr : Compute a std array at compile time

Question

I want to convert an \"array\" of bool to a integer sequence. So I need to compute an std::array at compile time.

Here is my code

Answer 1

This code looks correct and works when compiled as C++17. It uses std::array::begin, which only has been made constexpr in C++17.

A better compilation error can be achieved when using clang, which states:

:23:25: note: non-constexpr function 'begin' cannot be used in a constant expression
    auto it = array.begin();