模板化类型的最小值/最大值

Question

I have a rather basic question. Suppose I have a templated function:

bool is_max(std::uint32_t val) {
  return (val == std::numeric_limits<uint32_t>::max());
}

However, to make my function flexible, I'd like to use templates:

template <typename T>
bool is_max(T val) {
  return (val == ???);
}

The std::numeric_limits function would work with built-in types, but obviously doesn't work for user-defined types.

Is there some standard operator or function that the current built-in and most numeric types (I'm trying to use cnl::fixed_point ) that can be used here to find min/max value?

Answer 1

The way to handle this is to continue using std::numeric_limits , and add template specializations for all of the desired input types.

Quoting cppreference :

Implementations may provide specializations of std::numeric_limits for implementation-specific types: eg GCC provides std::numeric_limits<__int128> . Non-standard libraries may add specializations for library-provided types, eg OpenEXR provides std::numeric_limits<half> for a 16-bit floating-point type.