std::numeri..._specialized(3)

okay so bestie, welcome to the C++ Standard Libary manual — yes, that spelling is exactly what the header says — and this page is std::numeri..._specialized(3). We're here for std::numeric_limits::is_specialized, and it's giving tiny-but-iconic boolean main character energy. 💅✨

💖 NAME

• std::numeric_limits::is_specialized - std::numeric_limits::is_specialized — that's literally the name, bestie. No notes, it ate.

✨ Synopsis

The synopsis has two eras, because of course it does:

static const bool is_specialized;      (until C++11)
static constexpr bool is_specialized;  (since C++11)

And the actual tea: the value of std::numeric_limits<T>::is_specialized is true for all T for which there exists a specialization of std::numeric_limits. periodt. 🌈

🌸 Standard specializations

Here's the full roster — T on the left, value of std::numeric_limits<T>::is_specialized on the right:

• /* non-specialized */ → false
• bool → true
• char → true
• signed char → true
• unsigned char → true
• wchar_t → true
• char8_t (since C++20) → true
• char16_t (since C++11) → true
• char32_t (since C++11) → true
• short → true
• unsigned short → true
• int → true
• unsigned int → true
• long → true
• unsigned long → true
• long long (since C++11) → true
• unsigned long long (since C++11) → true
• float → true
• double → true
• long double → true

🌈 Example

The page says // Run this code, so obviously we run it, bestie:

        #include <iostream>
        #include <limits>
        #include <type_traits>

        int main()
        {
            enum E{};

            std::cout << std::boolalpha
                      << std::numeric_limits<bool>::is_specialized << '\n'
                      << std::numeric_limits<long long>::is_specialized << '\n'
                      << std::numeric_limits<std::true_type>::is_specialized <<
       '\n'
                      << std::numeric_limits<E>::is_specialized << '\n';
        }

Possible output:

        true
        true
        false
        false

🦋 See also

Each of these is also [static] — (public static member constant), iykyk:

• is_integer — identifies integer types. [static] (public static member constant).
• is_iec559 — identifies the IEC 559/IEEE 754 floating-point types. [static] (public static member constant).
• is_exact — identifies exact types. [static] (public static member constant).
• is_bounded — identifies types that represent a finite set of values. [static] (public static member constant).

mwah 💋 — source/version: http://cppreference.com, dated 2024.06.10, page std::numeri..._specialized(3). slay and goodbye 🎀