std::experi...amentalsTS)(3)

🎀 NAME 🎀

bestie, this is the std::experi...amentalsTS)(3) page from the C++ Standard Libary manual (yes, the header literally spells it “Libary” like that 💀). It’s the page for std::experimental::promise::promise(libraryfundamentalsTS) — and also std::experimental::promise::promise(libraryfundamentalsTS), because the NAME line says it twice, periodt.

✨ Synopsis ✨

          promise();                                           (1) (library
       fundamentals TS)
          template< class Alloc >                              (2) (library
       fundamentals TS)
          promise( std::allocator_arg_t, const Alloc& alloc );
          promise( promise&& other ) noexcept;                 (3) (library
       fundamentals TS)
          promise( const promise& other ) = delete;            (4) (library
       fundamentals TS)

💖 Description 💖

Constructs a std::experimental::promise object. Here’s the constructor tea, no cap:

1. Default constructor. Constructs the promise with an empty shared state.
2. Constructs the promise with an empty shared state. The shared state is allocated using alloc, which is treated as a type-erased allocator (see below).
3. Move constructor. Constructs the promise with the shared state of other using move semantics. After construction, other has no shared state.
4. std::experimental::promise is not copyable.

🧚 Type-erased allocator 🧚

The constructors of promise that take an allocator argument alloc treat that argument as a type-erased allocator. The memory resource pointer used by promise to allocate memory is determined using the allocator argument (if specified) as follows — here’s the mapping from the type of alloc to the value of the memory resource pointer:

• Non-existent (no allocator specified at time of construction) → the value of std::experimental::pmr::get_default_resource() at time of construction.
• std::nullptr_t → the value of std::experimental::pmr::get_default_resource() at time of construction.
• A pointer type convertible to std::experimental::pmr::memory_resource* → static_cast<std::experimental::pmr::memory_resource*>(alloc)
• std::experimental::pmr::memory_resource* → alloc (a pointer to a value of type std::experimental::pmr::memory_resource)
• A specialization of std::experimental::pmr::polymorphic_allocator → alloc.resource()
• Any other type meeting the Allocator requirements → std::experimental::pmr::resource_adaptor<A>(alloc), where A is the type of alloc. The pointer remains valid only for the lifetime of the promise object.
• None of the above → The program is ill-formed.

🌸 Parameters 🌸

• alloc — allocator to use to allocate the shared state
• other — another std::experimental::promise to acquire the state from

💀 Exceptions 💀

• 1,2) (none)

okay that’s the whole page, bestie 🫶 source/version: http://cppreference.com, 2024.06.10, and the title was std::experi...amentalsTS)(3). slay ✨