__GNU_CXX::__ALLOC_TRAITS(3)

🌸 __gnu_cxx::__alloc_traits — the manual page bestie 💅

ok so this is from the Library Functions Manual (libstdc++ girlies know 💖), and it's the page for __gnu_cxx:... typename >(3). Yes the title is lowkey unhinged, we love that for it. ✨

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🎀 NAME 🎀

__gnu_cxx::__alloc_traits< _Alloc, typename > — Uniform interface to C++98 and C++11 allocators.

no cap, that's the whole vibe: one interface, two allocator eras, zero drama 🦋

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✨ SYNOPSIS ✨

#include <alloc_traits.h>

Inherits std::allocator_traits< _Alloc >.

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👑 Public Types 👑

• typedef std::allocator_traits< _Alloc > _Base_type
• typedef _Alloc allocator_type
• typedef _Base_type::const_pointer const_pointer
• typedef const value_type & const_reference
• using const_void_pointer — the allocator's const void pointer type 🫶
• typedef _Base_type::difference_type difference_type
• using is_always_equal — whether all instances of the allocator type compare equal (do they all match? vibe check time 💅)
• typedef _Base_type::pointer pointer
• using propagate_on_container_copy_assignment — how the allocator is propagated on copy assignment
• using propagate_on_container_move_assignment — how the allocator is propagated on move assignment
• using propagate_on_container_swap — how the allocator is propagated on swap
• template<typename _Tp> using rebind_alloc
• template<typename _Tp> using rebind_traits
• typedef value_type & reference
• typedef _Base_type::size_type size_type
• typedef _Base_type::value_type value_type
• using void_pointer — the allocator's void pointer type 🌈

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🌟 Static Public Member Functions 🌟

• static constexpr bool _S_always_equal ()
• static constexpr bool _S_nothrow_move ()
• static constexpr void _S_on_swap (_Alloc &__a, _Alloc &__b)
• static constexpr bool _S_propagate_on_copy_assign ()
• static constexpr bool _S_propagate_on_move_assign ()
• static constexpr bool _S_propagate_on_swap ()
• static constexpr _Alloc _S_select_on_copy (const _Alloc &__a)
• static constexpr pointer allocate (_Alloc &__a, size_type __n) — Allocate memory.
• static constexpr pointer allocate (_Alloc &__a, size_type __n, const_void_pointer __hint) — Allocate memory.
• static constexpr pointer allocate (_Alloc &__a, size_type __n) — Allocate memory.
• static constexpr pointer allocate (_Alloc &__a, size_type __n, const_void_pointer __hint) — Allocate memory.
• static constexpr auto allocate_at_least (_Alloc &__a, size_type __n) -> allocation_result< pointer, size_type > — Allocate memory, generously. (yes she's generous, we stan 💖)
• template<typename _Ptr, typename... _Args> static constexpr std::__enable_if_t< __is_custom_pointer< _Ptr >::value > construct (_Alloc &__a, _Ptr __p, _Args &&... __args) noexcept(noexcept(_Base_type::construct(__a, std::__to_address(__p), std::forward< _Args >(__args)...)))
• template<typename _Tp, typename... _Args> static constexpr void construct (_Alloc &__a, _Tp *__p, _Args &&... __args) noexcept(_S_nothrow_construct< _Tp, _Args... >()) — Construct an object of type _Tp.
• static constexpr void deallocate (_Alloc &__a, pointer __p, size_type __n) — Deallocate memory.
• static constexpr void deallocate (_Alloc &__a, pointer __p, size_type __n) — Deallocate memory.
• template<typename _Ptr> static constexpr std::__enable_if_t< __is_custom_pointer< _Ptr >::value > destroy (_Alloc &__a, _Ptr __p) noexcept(noexcept(_Base_type::destroy(__a, std::__to_address(__p))))
• template<typename _Tp> static constexpr void destroy (_Alloc &__a, _Tp *__p) noexcept(_S_nothrow_destroy< _Tp >()) — Destroy an object of type _Tp.
• static constexpr size_type max_size (const _Alloc &__a) noexcept — the maximum supported allocation size.
• static constexpr _Alloc select_on_container_copy_construction (const _Alloc &__rhs) — obtain an allocator to use when copying a container.

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💜 Detailed Description 💜

template<typename _Alloc, typename = typename _Alloc::value_type>
struct __gnu_cxx::__alloc_traits< _Alloc, typename >

"Uniform interface to C++98 and C++11 allocators." periodt 💅

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🦋 Member Typedef Documentation 🦋

• template<typename _Alloc> using std::allocator_traits< _Alloc >::const_void_pointer [inherited] — the allocator's const void pointer type. Alloc::const_void_pointer if that type exists, otherwise pointer_traits<pointer>::rebind<const void>
• template<typename _Alloc> using std::allocator_traits< _Alloc >::is_always_equal [inherited] — whether all instances of the allocator type compare equal. Alloc::is_always_equal if that type exists, otherwise is_empty<Alloc>::type
• template<typename _Alloc> using std::allocator_traits< _Alloc >::propagate_on_container_copy_assignment [inherited] — how the allocator is propagated on copy assignment. Alloc::propagate_on_container_copy_assignment if that type exists, otherwise false_type
• template<typename _Alloc> using std::allocator_traits< _Alloc >::propagate_on_container_move_assignment [inherited] — how the allocator is propagated on move assignment. Alloc::propagate_on_container_move_assignment if that type exists, otherwise false_type
• template<typename _Alloc> using std::allocator_traits< _Alloc >::propagate_on_container_swap [inherited] — how the allocator is propagated on swap. Alloc::propagate_on_container_swap if that type exists, otherwise false_type
• template<typename _Alloc> using std::allocator_traits< _Alloc >::void_pointer [inherited] — the allocator's void pointer type. Alloc::void_pointer if that type exists, otherwise pointer_traits<pointer>::rebind<void>

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🔥 Member Function Documentation 🔥

allocate (the non-inherited one, no hint) 🍓

template<typename _Alloc, typename = typename _Alloc::value_type> constexpr
    pointer std::allocator_traits< _Alloc >::allocate (_Alloc & __a,
    size_type __n) [inline],  [static],  [nodiscard],  [constexpr]

Allocate memory.

Parameters:

• __a — an allocator.
• __n — the number of objects to allocate space for.

Calls a.allocate(n) 💫

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allocate (non-inherited, with hint) 🍓

template<typename _Alloc, typename = typename _Alloc::value_type> constexpr
    pointer std::allocator_traits< _Alloc >::allocate (_Alloc & __a,
    size_type __n, const_void_pointer __hint) [inline],  [static],
    [nodiscard],  [constexpr]

Allocate memory.

Parameters:

• __a — an allocator.
• __n — the number of objects to allocate space for.
• __hint — aid to locality. (a lil hint, a lil nudge, she's helping 💅)

Returns: memory of suitable size and alignment for n objects of type value_type.

Returns a.allocate(n, hint) if that expression is well-formed, otherwise returns a.allocate(n).

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allocate (inherited, no hint) 🌸

template<typename _Alloc> constexpr pointer std::allocator_traits< _Alloc
    >::allocate (_Alloc & __a, size_type __n) [inline],  [static],
    [nodiscard],  [constexpr],  [inherited]

Allocate memory.

Parameters:

• __a — an allocator.
• __n — the number of objects to allocate space for.

Calls a.allocate(n) ✨

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allocate (inherited, with hint) 🌸

template<typename _Alloc> constexpr pointer std::allocator_traits< _Alloc
    >::allocate (_Alloc & __a, size_type __n, const_void_pointer __hint)
    [inline],  [static],  [nodiscard],  [constexpr],  [inherited]

Allocate memory.

Parameters:

• __a — an allocator.
• __n — the number of objects to allocate space for.
• __hint — aid to locality.

Returns: memory of suitable size and alignment for n objects of type value_type.

Returns a.allocate(n, hint) if that expression is well-formed, otherwise returns a.allocate(n).

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allocate_at_least 🎀

template<typename _Alloc> constexpr auto std::allocator_traits< _Alloc
    >::allocate_at_least (_Alloc & __a, size_type __n) -> allocation_result<
    pointer, size_type > [inline],  [static],  [nodiscard],  [constexpr],
    [inherited]

Allocate memory, generously. (she's giving main character energy and extra space 👑)

Parameters:

• __a — an allocator.
• __n — the minimum number of objects to allocate space for.

Returns: memory of suitable size and alignment for n or more contiguous objects of type value_type.

Returns a.allocate_at_least(n) if that expression is well-formed, else { a.allocate(n), n }. When an allocator is obliged to reserve more space than required for the cited n objects, it may deliver the extra space to the caller. 🫶

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construct 💖

template<typename _Alloc, typename = typename _Alloc::value_type>
    template<typename _Tp, typename... _Args> constexpr void
    std::allocator_traits< _Alloc >::construct (_Alloc & __a, _Tp * __p,
    _Args &&... __args) [inline],  [static],  [constexpr],  [noexcept]

Construct an object of type _Tp.

Parameters:

• __a — an allocator.
• __p — pointer to memory of suitable size and alignment for Tp
• __args — constructor arguments.

Calls __a.construct(__p, std::forward<Args>(__args)...) if that expression is well-formed, otherwise uses placement-new to construct an object of type _Tp at location __p from the arguments __args... 🌈

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deallocate (non-inherited) 🧚

template<typename _Alloc, typename = typename _Alloc::value_type> constexpr
    void std::allocator_traits< _Alloc >::deallocate (_Alloc & __a, pointer
    __p, size_type __n) [inline],  [static],  [constexpr]

Deallocate memory.

Parameters:

• __a — an allocator.
• __p — pointer to the memory to deallocate.
• __n — the number of objects space was allocated for.

Calls a.deallocate(p, n) 💫

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deallocate (inherited) 🧚

template<typename _Alloc> constexpr void std::allocator_traits< _Alloc
    >::deallocate (_Alloc & __a, pointer __p, size_type __n) [inline],
    [static],  [constexpr],  [inherited]

Deallocate memory.

Parameters:

• __a — an allocator.
• __p — pointer to the memory to deallocate.
• __n — the number of objects space was allocated for.

Calls a.deallocate(p, n) ✨

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destroy 💀

template<typename _Alloc, typename = typename _Alloc::value_type>
    template<typename _Tp> constexpr void std::allocator_traits< _Alloc
    >::destroy (_Alloc & __a, _Tp * __p) [inline],  [static],  [constexpr],
    [noexcept]

Destroy an object of type _Tp.

Parameters:

• __a — an allocator.
• __p — pointer to the object to destroy

Calls __a.destroy(__p) if that expression is well-formed, otherwise calls __p->~_Tp() 🫶

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max_size 💅

template<typename _Alloc, typename = typename _Alloc::value_type> constexpr
    size_type std::allocator_traits< _Alloc >::max_size (const _Alloc & __a)
    [inline],  [static],  [constexpr],  [noexcept]

The maximum supported allocation size.

Parameters:

• __a — an allocator.

Returns: __a.max_size() or numeric_limits<size_type>::max()

Returns __a.max_size() if that expression is well-formed, otherwise returns numeric_limits<size_type>::max() 🌟

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select_on_container_copy_construction 🦋

template<typename _Alloc> constexpr _Alloc std::allocator_traits< _Alloc
    >::select_on_container_copy_construction (const _Alloc & __rhs)
    [inline],  [static],  [constexpr],  [inherited]

Obtain an allocator to use when copying a container.

Parameters:

• __rhs — an allocator.

Returns: __rhs.select_on_container_copy_construction() or __rhs

Returns __rhs.select_on_container_copy_construction() if that expression is well-formed, otherwise returns __rhs 💖

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🌈 Author 🌈

Generated automatically by Doxygen for libstdc++ from the source code.

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ok that's the whole page bestie, every flag, every typedef, every noexcept, all of it. iykyk 💅

and that's a wrap! this page came to you from libstdc++, and the manual it lives in is Library Functions Manual — it's dated and versioned as libstdc++ __gnu_cxx:... typename >(3), so shoutout to the libstdc++ girlies for keeping her iconic. bye bestie, go allocate something responsibly 🎀✨🫶