typedef make_unsigned<const char>::type test22_type;
static_assert(is_same<test22_type, const unsigned char>::value, "");
-#ifdef _GLIBCXX_USE_WCHAR_T
typedef make_unsigned<volatile wchar_t>::type test23_type;
static_assert(is_unsigned<test23_type>::value
&& is_volatile<test23_type>::value
&& sizeof(test23_type) == sizeof(volatile wchar_t), "");
-#endif
typedef make_unsigned<test_enum>::type test24_type;
static_assert(is_same<test24_type, unsigned short>::value, "");