constexpr and endianness

Question

A common question that comes up from time to time in the world of C++ programming is compile-time determination of endianness. Usually this is done with barely portable #if

Answer 1

There is std::endian in the upcoming C++20.

#include 

constexpr bool little_endian() noexcept
{
    return std::endian::native == std::endian::little;
}