#if defined(alignas)  /* check C++ keywords */ \
    || defined(alignof) \
    || defined(asm) \
    || defined(auto) \
    || defined(bool) \
    || defined(break) \
    || defined(case) \
    || defined(catch) \
    || defined(char) \
    || defined(char16_t) \
    || defined(char32_t) \
    || defined(class) \
    || defined(const) \
    || defined(const_cast) \
    || defined(constexpr) \
    || defined(continue) \
    || defined(decltype) \
    || defined(default) \
    || defined(delete) \
    || defined(do) \
    || defined(double) \
    || defined(dynamic_cast) \
    || defined(else) \
    || defined(enum) \
    || defined(explicit) \
    || defined(export) \
    || defined(extern) \
    || defined(false) \
    || defined(float) \
    || defined(for) \
    || defined(friend) \
    || defined(goto) \
    || defined(if) \
    || defined(inline) \
    || defined(int) \
    || defined(long) \
    || defined(mutable) \
    || defined(namespace) \
    || defined(new) && defined(_ENFORCE_BAN_OF_MACRO_NEW) \
    || defined(noexcept) \
    || defined(nullptr) \
    || defined(operator) \
    || defined(private) \
    || defined(protected) \
    || defined(public) \
    || defined(register) \
    || defined(reinterpret_cast) \
    || defined(return) \
    || defined(short) \
    || defined(signed) \
    || defined(sizeof) \
    || defined(static) \
    || defined(static_assert) \
    || defined(static_cast) \
    || defined(struct) \
    || defined(switch) \
    || defined(template) \
    || defined(this) \
    || defined(thread_local) \
    || defined(throw) \
    || defined(true) \
    || defined(try) \
    || defined(typedef) \
    || defined(typeid) \
    || defined(typename) \
    || defined(union) \
    || defined(unsigned) \
    || defined(using) \
    || defined(virtual) \
    || defined(void) \
    || defined(volatile) \
    || defined(wchar_t) \
    || defined(while)
   #error keyword defined before including C++ standard header
  #endif /* defined... */