c++ - std::is_unsigned 是否暗示 std::is_integral

Question

如果我需要满足 std::is_unsigned 和 std::is_integral 的类型，我是必须同时检查还是只检查 std::is_unsigned?

Answer 1

cppreference 有此行 is_unsigned ( https://en.cppreference.com/w/cpp/types/is_unsigned ):

this results in true for the unsigned integer types and the type bool and in false for the signed integer types and the floating-point types. For any other type, value is false.

因此，如果 is_unsigned 为 true，则 is_integral 也为真。