std::is_implicit_lifetime(3)

💖 NAME 💖

std::is_implicit_lifetime — std::is_implicit_lifetime.

okay so bestie, welcome to the std::is_implicit_lifetime page from the C++ Standard Libary manual — yes, that manual name is literally right there at the top in the original header, and we're folding it in here instead of copying the whole header line, periodt. 💅

✨ Synopsis ✨

Here's the whole shape of it, no cap:

Defined in header <type_traits>
template< class T >              (since C++23)
struct is_implicit_lifetime;

std::is_implicit_lifetime is a UnaryTypeTrait.

If T is an implicit-lifetime type, it provides the member constant value equal to true. For any other type, value is false.

The behavior is undefined if T is an incomplete type other than an array type or (possibly cv-qualified) void. Like, that's the scary one — don't do it, fr fr. 😭

If the program adds specializations for std::is_implicit_lifetime or std::is_implicit_lifetime_v, the behavior is undefined.

🧩 Template parameters

• T — a type to check

🧚 Helper variable template

template< class T >
inline constexpr bool is_implicit_lifetime_v =
(since C++23)
is_implicit_lifetime<T>::value;

🧬 Inherited from std::integral_constant

🌟 Member constants

• value — true if T is an implicit-lifetime type, false otherwise. [static] (public static member constant)

🎀 Member functions

• operator bool — converts the object to bool, returns value (public member function)
• operator() — returns value (C++14) (public member function)

🦋 Member types

• value_type — bool
• type — std::integral_constant<bool, value>

📝 Notes ✨

• Feature-test macro: __cpp_lib_is_implicit_lifetime — value 202302L (C++23), feature std::is_implicit_lifetime

🍓 Example 🍓

This section is incomplete. Reason: example.

That's literally it, bestie — no example yet, just the reason. 🙈

👀 See also 👀

• is_scalar — checks if a type is a scalar type (C++11) (class template)
• is_array — checks if a type is an array type (C++11) (class template)
• is_aggregate — checks if a type is an aggregate type (C++17) (class template)
• start_lifetime_as — implicitly creates objects in given storage with the object representation reused (C++23) (function template)
• start_lifetime_as_array — implicitly creates objects in given storage with the object representation reused (C++23) (function template)

🏷️ Category 🏷️

• Todo with reason

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okay that's the whole page, bestie 💅 big shoutout to http://cppreference.com, the 2024.06.10 version, and the std::is_implicit_lifetime(3) page itself — mwah 💋✨