message: core: revise syntax to support Visual C++ 2013
diff: @@ -49,7 +49,12 @@ private:
  typedef decltype(check<C>(0)) type;
  public:
  +#if __cplusplus >= 201103L || (defined(_MSC_VER) && _MSC_VER >= 1900/*MSVS 2015*/)
  static CV_CONSTEXPR bool value = type::value;
  +#else
  + // support MSVS 2013
  + static const int value = type::value;
  +#endif
  };
  } // namespace sfinae
  