message: quench MSVC warning
  [ci skip]
diff: # pragma warning(disable: 4702) // warning C4702: unreachable code
  # pragma warning(disable: 4522) // warning C4522: multiple assignment operators specified
  # pragma warning(disable: 4310) // warning C4310: cast truncates constant value
  +# pragma warning(disable: 4127) // warning C4127: conditional expression is constant
  #elif defined(__GNUC__) && !defined(__clang__)
  # pragma GCC diagnostic push
  # pragma GCC diagnostic ignored "-Wclass-memaccess"
  