Standard library header <memory>
From cppreference.com
This header is part of the dynamic memory management library.
Includes | |
(C++20) |
Three-way comparison operator support |
Classes | |
Pointer traits | |
(C++11) |
provides information about pointer-like types (class template) |
Garbage collector support | |
(C++11)(removed in C++23) |
lists pointer safety models (enum) |
Allocators | |
the default allocator (class template) | |
(C++11) |
provides information about allocator types (class template) |
(C++23) |
records the address and the actual size of storage allocated by allocate_at_least (class template) |
(C++11) |
checks if the specified type supports uses-allocator construction (class template) |
Uninitialized storage | |
(deprecated in C++17)(removed in C++20) |
an iterator that allows standard algorithms to store results in uninitialized memory (class template) |
Smart pointers | |
(C++11) |
smart pointer with unique object ownership semantics (class template) |
(C++11) |
smart pointer with shared object ownership semantics (class template) |
(C++11) |
weak reference to an object managed by std::shared_ptr (class template) |
(deprecated in C++11)(removed in C++17) |
smart pointer with strict object ownership semantics (class template) |
Helper classes | |
(C++20) |
atomic shared pointer (class template specialization) |
(C++20) |
atomic weak pointer (class template specialization) |
(C++11) |
provides mixed-type owner-based ordering of shared and weak pointers (class template) |
(C++26) |
provides owner-based hashing for shared and weak pointers (class) |
(C++26) |
provides mixed-type owner-based equal comparisons of shared and weak pointers (class) |
(C++11) |
allows an object to create a shared_ptr referring to itself (class template) |
(C++11) |
exception thrown when accessing a weak_ptr which refers to already destroyed object (class) |
(C++11) |
default deleter for unique_ptr (class template) |
(C++11) |
hash support for std::unique_ptr (class template specialization) |
(C++11) |
hash support for std::shared_ptr (class template specialization) |
Smart pointer adaptors | |
(C++23) |
interoperates with foreign pointer setters and resets a smart pointer on destruction (class template) |
(C++23) |
interoperates with foreign pointer setters, obtains the initial pointer value from a smart pointer, and resets it on destruction (class template) |
Forward declarations | |
Defined in header
<functional> | |
(C++11) |
hash function object (class template) |
Defined in header
<atomic> | |
(C++11) |
atomic class template and specializations for bool, integral, floating-point,(since C++20) and pointer types (class template) |
Tags | |
(C++11) |
a tag used to select allocator-aware constructors (tag) |
Functions | |
Uses-allocator construction | |
prepares the argument list matching the flavor of uses-allocator construction required by the given type (function template) | |
(C++20) |
creates an object of the given type by means of uses-allocator construction (function template) |
creates an object of the given type at specified memory location by means of uses-allocator construction (function template) | |
Miscellaneous | |
(C++20) |
obtains a raw pointer from a pointer-like type (function template) |
(C++11) |
obtains actual address of an object, even if the & operator is overloaded (function template) |
(C++11) |
aligns a pointer in a buffer (function) |
(C++20) |
informs the compiler that a pointer is aligned (function template) |
(C++26) |
checks whether the pointer points to an object whose alignment has at least the given value (function template) |
Explicit lifetime management | |
implicitly creates objects in given storage with the object representation reused (function template) | |
Garbage collector support | |
(C++11)(removed in C++23) |
declares that an object can not be recycled (function) |
(C++11)(removed in C++23) |
declares that an object can be recycled (function template) |
(C++11)(removed in C++23) |
declares that a memory area does not contain traceable pointers (function) |
(C++11)(removed in C++23) |
cancels the effect of std::declare_no_pointers (function) |
(C++11)(removed in C++23) |
returns the current pointer safety model (function) |
Uninitialized storage | |
copies a range of objects to an uninitialized area of memory (function template) | |
(C++11) |
copies a number of objects to an uninitialized area of memory (function template) |
copies an object to an uninitialized area of memory, defined by a range (function template) | |
copies an object to an uninitialized area of memory, defined by a start and a count (function template) | |
(C++17) |
moves a range of objects to an uninitialized area of memory (function template) |
(C++17) |
moves a number of objects to an uninitialized area of memory (function template) |
constructs objects by default-initialization in an uninitialized area of memory, defined by a range (function template) | |
constructs objects by default-initialization in an uninitialized area of memory, defined by a start and a count (function template) | |
constructs objects by value-initialization in an uninitialized area of memory, defined by a range (function template) | |
constructs objects by value-initialization in an uninitialized area of memory, defined by a start and a count (function template) | |
(C++20) |
creates an object at a given address (function template) |
(C++17) |
destroys an object at a given address (function template) |
(C++17) |
destroys a range of objects (function template) |
(C++17) |
destroys a number of objects in a range (function template) |
(deprecated in C++17)(removed in C++20) |
obtains uninitialized storage (function template) |
(deprecated in C++17)(removed in C++20) |
frees uninitialized storage (function template) |
Smart pointer non-member operations | |
(C++14)(C++20) |
creates a unique pointer that manages a new object (function template) |
(removed in C++20)(C++20) |
compares to another unique_ptr or with nullptr (function template) |
creates a shared pointer that manages a new object (function template) | |
creates a shared pointer that manages a new object allocated using an allocator (function template) | |
applies static_cast, dynamic_cast, const_cast, or reinterpret_cast to the stored pointer (function template) | |
returns the deleter of specified type, if owned (function template) | |
(removed in C++20)(removed in C++20)(removed in C++20)(removed in C++20)(removed in C++20)(C++20) |
compares with another shared_ptr or with nullptr (function template) |
outputs the value of the stored pointer to an output stream (function template) | |
(C++20) |
outputs the value of the managed pointer to an output stream (function template) |
(C++11) |
specializes the std::swap algorithm (function template) |
(C++11) |
specializes the std::swap algorithm (function template) |
(C++11) |
specializes the std::swap algorithm (function template) |
Smart pointer adaptor creation | |
(C++23) |
creates an out_ptr_t with an associated smart pointer and resetting arguments (function template) |
(C++23) |
creates an inout_ptr_t with an associated smart pointer and resetting arguments (function template) |
specializes atomic operations for std::shared_ptr (function template) |
Function-like entities | |
Defined in namespace
std::ranges | |
Uninitialized storage | |
(C++20) |
copies a range of objects to an uninitialized area of memory (algorithm function object) |
(C++20) |
copies a number of objects to an uninitialized area of memory (algorithm function object) |
(C++20) |
copies an object to an uninitialized area of memory, defined by a range (algorithm function object) |
(C++20) |
copies an object to an uninitialized area of memory, defined by a start and a count (algorithm function object) |
(C++20) |
moves a range of objects to an uninitialized area of memory (algorithm function object) |
(C++20) |
moves a number of objects to an uninitialized area of memory (algorithm function object) |
constructs objects by default-initialization in an uninitialized area of memory, defined by a range (algorithm function object) | |
constructs objects by default-initialization in an uninitialized area of memory, defined by a start and count (algorithm function object) | |
constructs objects by value-initialization in an uninitialized area of memory, defined by a range (algorithm function object) | |
constructs objects by value-initialization in an uninitialized area of memory, defined by a start and a count (algorithm function object) | |
(C++20) |
creates an object at a given address (algorithm function object) |
(C++20) |
destroys an object at a given address (algorithm function object) |
(C++20) |
destroys a range of objects (algorithm function object) |
(C++20) |
destroys a number of objects in a range (algorithm function object) |
[edit] Synopsis
#include <compare> namespace std { // pointer traits template<class Ptr> struct pointer_traits; template<class T> struct pointer_traits<T*>; // pointer conversion template<class T> constexpr T* to_address(T* p) noexcept; template<class Ptr> constexpr auto to_address(const Ptr& p) noexcept; // pointer alignment void* align(size_t alignment, size_t size, void*& ptr, size_t& space); template<size_t N, class T> constexpr T* assume_aligned(T* ptr); // explicit lifetime management template<class T> T* start_lifetime_as(void* p) noexcept; // freestanding template<class T> const T* start_lifetime_as(const void* p) noexcept; // freestanding template<class T> volatile T* start_lifetime_as(volatile void* p) noexcept; // freestanding template<class T> const volatile T* start_lifetime_as(const volatile void* p) noexcept; // freestanding template<class T> T* start_lifetime_as_array(void* p, size_t n) noexcept; // freestanding template<class T> const T* start_lifetime_as_array(const void* p, size_t n) noexcept; // freestanding template<class T> volatile T* start_lifetime_as_array(volatile void* p, size_t n) noexcept; // freestanding template<class T> const volatile T* start_lifetime_as_array(const volatile void* p, // freestanding size_t n) noexcept; // allocator argument tag struct allocator_arg_t { explicit allocator_arg_t() = default; }; inline constexpr allocator_arg_t allocator_arg{}; // uses_allocator template<class T, class Alloc> struct uses_allocator; // uses_allocator template<class T, class Alloc> inline constexpr bool uses_allocator_v = uses_allocator<T, Alloc>::value; // uses-allocator construction template<class T, class Alloc, class... Args> constexpr auto uses_allocator_construction_args(const Alloc& alloc, Args&&... args) noexcept; template<class T, class Alloc, class Tuple1, class Tuple2> constexpr auto uses_allocator_construction_args(const Alloc& alloc, piecewise_construct_t, Tuple1&& x, Tuple2&& y) noexcept; template<class T, class Alloc> constexpr auto uses_allocator_construction_args(const Alloc& alloc) noexcept; template<class T, class Alloc, class U, class V> constexpr auto uses_allocator_construction_args(const Alloc& alloc, U&& u, V&& v) noexcept; template<class T, class Alloc, class U, class V> constexpr auto uses_allocator_construction_args(const Alloc& alloc, const pair<U, V>& pr) noexcept; template<class T, class Alloc, class U, class V> constexpr auto uses_allocator_construction_args(const Alloc& alloc, pair<U, V>&& pr) noexcept; template<class T, class Alloc, class... Args> constexpr T make_obj_using_allocator(const Alloc& alloc, Args&&... args); template<class T, class Alloc, class... Args> constexpr T* uninitialized_construct_using_allocator(T* p, const Alloc& alloc, Args&&... args); // allocator traits template<class Alloc> struct allocator_traits; template<class Pointer, class SizeType = size_t> struct allocation_result { Pointer ptr; SizeType count; }; // the default allocator template<class T> class allocator; template<class T, class U> constexpr bool operator==(const allocator<T>&, const allocator<U>&) noexcept; // addressof template<class T> constexpr T* addressof(T& r) noexcept; template<class T> const T* addressof(const T&&) = delete; // specialized algorithms // special memory concepts template<class I> concept no-throw-input-iterator = /* see description */; // exposition only template<class I> concept no-throw-forward-iterator = /* see description */; // exposition only template<class S, class I> concept no-throw-sentinel-for = /* see description */; // exposition only template<class R> concept no-throw-input-range = /* see description */; // exposition only template<class R> concept no-throw-forward-range = /* see description */; // exposition only template<class NoThrowForwardIt> void uninitialized_default_construct(NoThrowForwardIt first, NoThrowForwardIt last); template<class ExecutionPolicy, class NoThrowForwardIt> void uninitialized_default_construct(ExecutionPolicy&& exec, NoThrowForwardIt first, NoThrowForwardIt last); template<class NoThrowForwardIt, class Size> NoThrowForwardIt uninitialized_default_construct_n(NoThrowForwardIt first, Size n); template<class ExecutionPolicy, class NoThrowForwardIt, class Size> NoThrowForwardIt uninitialized_default_construct_n(ExecutionPolicy&& exec, NoThrowForwardIt first, Size n); namespace ranges { template<no-throw-forward-iterator I, no-throw-sentinel-for<I> S> requires default_initializable<iter_value_t<I>> I uninitialized_default_construct(I first, S last); template<no-throw-forward-range R> requires default_initializable<range_value_t<R>> borrowed_iterator_t<R> uninitialized_default_construct(R&& r); template<no-throw-forward-iterator I> requires default_initializable<iter_value_t<I>> I uninitialized_default_construct_n(I first, iter_difference_t<I> n); } template<class NoThrowForwardIterator> void uninitialized_value_construct(NoThrowForwardIterator first, NoThrowForwardIterator last); template<class ExecutionPolicy, class NoThrowForwardIt> void uninitialized_value_construct(ExecutionPolicy&& exec, NoThrowForwardIt first, NoThrowForwardIt last); template<class NoThrowForwardIt, class Size> NoThrowForwardIt uninitialized_value_construct_n(NoThrowForwardIt first, Size n); template<class ExecutionPolicy, class NoThrowForwardIt, class Size> NoThrowForwardIt uninitialized_value_construct_n(ExecutionPolicy&& exec, NoThrowForwardIt first, Size n); namespace ranges { template<no-throw-forward-iterator I, no-throw-sentinel-for<I> S> requires default_initializable<iter_value_t<I>> I uninitialized_value_construct(I first, S last); template<no-throw-forward-range R> requires default_initializable<range_value_t<R>> borrowed_iterator_t<R> uninitialized_value_construct(R&& r); template<no-throw-forward-iterator I> requires default_initializable<iter_value_t<I>> I uninitialized_value_construct_n(I first, iter_difference_t<I> n); } template<class InputIt, class NoThrowForwardIt> NoThrowForwardIt uninitialized_copy(InputIt first, InputIt last, NoThrowForwardIt result); template<class ExecutionPolicy, class ForwardIt, class NoThrowForwardIt> NoThrowForwardIt uninitialized_copy(ExecutionPolicy&& exec, ForwardIt first, ForwardIt last, NoThrowForwardIt result); template<class InputIt, class Size, class NoThrowForwardIt> NoThrowForwardIt uninitialized_copy_n(InputIt first, Size n, NoThrowForwardIt result); template<class ExecutionPolicy, class ForwardIt, class Size, class NoThrowForwardIt> NoThrowForwardIt uninitialized_copy_n(ExecutionPolicy&& exec, ForwardIt first, Size n, NoThrowForwardIt result); namespace ranges { template<class I, class O> using uninitialized_copy_result = in_out_result<I, O>; template<input_iterator I, sentinel_for<I> S1, no-throw-forward-iterator O, no-throw-sentinel-for<O> S2> requires constructible_from<iter_value_t<O>, iter_reference_t<I>> uninitialized_copy_result<I, O> uninitialized_copy(I ifirst, S1 ilast, O ofirst, S2 olast); template<input_range IR, no-throw-forward-range OR> requires constructible_from<range_value_t<OR>, range_reference_t<IR>> uninitialized_copy_result<borrowed_iterator_t<IR>, borrowed_iterator_t<OR>> uninitialized_copy(IR&& in_range, OR&& out_range); template<class I, class O> using uninitialized_copy_n_result = in_out_result<I, O>; template<input_iterator I, no-throw-forward-iterator O, no-throw-sentinel-for<O> S> requires constructible_from<iter_value_t<O>, iter_reference_t<I>> uninitialized_copy_n_result<I, O> uninitialized_copy_n(I ifirst, iter_difference_t<I> n, O ofirst, S olast); } template<class InputIt, class NoThrowForwardIt> NoThrowForwardIt uninitialized_move(InputIt first, InputIt last, NoThrowForwardIt result); template<class ExecutionPolicy, class ForwardIt, class NoThrowForwardIt> NoThrowForwardIt uninitialized_move(ExecutionPolicy&& exec, ForwardIt first, ForwardIt last, NoThrowForwardIt result); template<class InputIt, class Size, class NoThrowForwardIt> pair<InputIt, NoThrowForwardIt> uninitialized_move_n(InputIt first, Size n, NoThrowForwardIt result); template<class ExecutionPolicy, class ForwardIt, class Size, class NoThrowForwardIt> pair<ForwardIt, NoThrowForwardIt> uninitialized_move_n(ExecutionPolicy&& exec, ForwardIt first, Size n, NoThrowForwardIt result); namespace ranges { template<class I, class O> using uninitialized_move_result = in_out_result<I, O>; template<input_iterator I, sentinel_for<I> S1, no-throw-forward-iterator O, no-throw-sentinel-for<O> S2> requires constructible_from<iter_value_t<O>, iter_rvalue_reference_t<I>> uninitialized_move_result<I, O> uninitialized_move(I ifirst, S1 ilast, O ofirst, S2 olast); template<input_range IR, no-throw-forward-range OR> requires constructible_from<range_value_t<OR>, range_rvalue_reference_t<IR>> uninitialized_move_result<borrowed_iterator_t<IR>, borrowed_iterator_t<OR>> uninitialized_move(IR&& in_range, OR&& out_range); template<class I, class O> using uninitialized_move_n_result = in_out_result<I, O>; template<input_iterator I, no-throw-forward-iterator O, no-throw-sentinel-for<O> S> requires constructible_from<iter_value_t<O>, iter_rvalue_reference_t<I>> uninitialized_move_n_result<I, O> uninitialized_move_n(I ifirst, iter_difference_t<I> n, O ofirst, S olast); } template<class NoThrowForwardIt, class T> void uninitialized_fill(NoThrowForwardIt first, NoThrowForwardIt last, const T& x); template<class ExecutionPolicy, class NoThrowForwardIt, class T> void uninitialized_fill(ExecutionPolicy&& exec, NoThrowForwardIt first, NoThrowForwardIt last, const T& x); template<class NoThrowForwardIt, class Size, class T> NoThrowForwardIt uninitialized_fill_n(NoThrowForwardIt first, Size n, const T& x); template<class ExecutionPolicy, class NoThrowForwardIt, class Size, class T> NoThrowForwardIt uninitialized_fill_n(ExecutionPolicy&& exec, NoThrowForwardIt first, Size n, const T& x); namespace ranges { template<no-throw-forward-iterator I, no-throw-sentinel-for<I> S, class T> requires constructible_from<iter_value_t<I>, const T&> I uninitialized_fill(I first, S last, const T& x); template<no-throw-forward-range R, class T> requires constructible_from<range_value_t<R>, const T&> borrowed_iterator_t<R> uninitialized_fill(R&& r, const T& x); template<no-throw-forward-iterator I, class T> requires constructible_from<iter_value_t<I>, const T&> I uninitialized_fill_n(I first, iter_difference_t<I> n, const T& x); } // construct_at template<class T, class... Args> constexpr T* construct_at(T* location, Args&&... args); namespace ranges { template<class T, class... Args> constexpr T* construct_at(T* location, Args&&... args); } // destroy template<class T> constexpr void destroy_at(T* location); template<class NoThrowForwardIt> constexpr void destroy(NoThrowForwardIt first, NoThrowForwardIt last); template<class ExecutionPolicy, class NoThrowForwardIt> void destroy(ExecutionPolicy&& exec, NoThrowForwardIt first, NoThrowForwardIt last); template<class NoThrowForwardIt, class Size> constexpr NoThrowForwardIt destroy_n(NoThrowForwardIt first, Size n); template<class ExecutionPolicy, class NoThrowForwardIt, class Size> NoThrowForwardIt destroy_n(ExecutionPolicy&& exec, NoThrowForwardIt first, Size n); namespace ranges { template<destructible T> constexpr void destroy_at(T* location) noexcept; template<no-throw-input-iterator I, no-throw-sentinel-for<I> S> requires destructible<iter_value_t<I>> constexpr I destroy(I first, S last) noexcept; template<no-throw-input-range R> requires destructible<range_value_t<R>> constexpr borrowed_iterator_t<R> destroy(R&& r) noexcept; template<no-throw-input-iterator I> requires destructible<iter_value_t<I>> constexpr I destroy_n(I first, iter_difference_t<I> n) noexcept; } // class template unique_ptr template<class T> struct default_delete; template<class T> struct default_delete<T[]>; template<class T, class D = default_delete<T>> class unique_ptr; template<class T, class D> class unique_ptr<T[], D>; template<class T, class... Args> unique_ptr<T> make_unique(Args&&... args); // T is not array template<class T> unique_ptr<T> make_unique(size_t n); // T is U[] template<class T, class... Args> /* unspecified */ make_unique(Args&&...) = delete; // T is U[N] template<class T> unique_ptr<T> make_unique_for_overwrite(); // T is not array template<class T> unique_ptr<T> make_unique_for_overwrite(size_t n); // T is U[] template<class T, class... Args> /* unspecified */ make_unique_for_overwrite(Args&&...) = delete; // T is U[N] template<class T, class D> void swap(unique_ptr<T, D>& x, unique_ptr<T, D>& y) noexcept; template<class T1, class D1, class T2, class D2> bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); template<class T1, class D1, class T2, class D2> bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); template<class T1, class D1, class T2, class D2> bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); template<class T1, class D1, class T2, class D2> bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); template<class T1, class D1, class T2, class D2> bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); template<class T1, class D1, class T2, class D2> requires three_way_comparable_with<typename unique_ptr<T1, D1>::pointer, typename unique_ptr<T2, D2>::pointer> compare_three_way_result_t<typename unique_ptr<T1, D1>::pointer, typename unique_ptr<T2, D2>::pointer> operator<=>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); template<class T, class D> bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept; template<class T, class D> bool operator<(const unique_ptr<T, D>& x, nullptr_t); template<class T, class D> bool operator<(nullptr_t, const unique_ptr<T, D>& y); template<class T, class D> bool operator>(const unique_ptr<T, D>& x, nullptr_t); template<class T, class D> bool operator>(nullptr_t, const unique_ptr<T, D>& y); template<class T, class D> bool operator<=(const unique_ptr<T, D>& x, nullptr_t); template<class T, class D> bool operator<=(nullptr_t, const unique_ptr<T, D>& y); template<class T, class D> bool operator>=(const unique_ptr<T, D>& x, nullptr_t); template<class T, class D> bool operator>=(nullptr_t, const unique_ptr<T, D>& y); template<class T, class D> requires three_way_comparable<typename unique_ptr<T, D>::pointer> compare_three_way_result_t<typename unique_ptr<T, D>::pointer> operator<=>(const unique_ptr<T, D>& x, nullptr_t); template<class E, class T, class Y, class D> basic_ostream<E, T>& operator<<(basic_ostream<E, T>& os, const unique_ptr<Y, D>& p); // class bad_weak_ptr class bad_weak_ptr; // class template shared_ptr template<class T> class shared_ptr; // shared_ptr creation template<class T, class... Args> shared_ptr<T> make_shared(Args&&... args); // T is not array template<class T, class A, class... Args> shared_ptr<T> allocate_shared(const A& a, Args&&... args); // T is not array template<class T> shared_ptr<T> make_shared(size_t N); // T is U[] template<class T, class A> shared_ptr<T> allocate_shared(const A& a, size_t N); // T is U[] template<class T> shared_ptr<T> make_shared(); // T is U[N] template<class T, class A> shared_ptr<T> allocate_shared(const A& a); // T is U[N] template<class T> shared_ptr<T> make_shared(size_t N, const remove_extent_t<T>& u); // T is U[] template<class T, class A> shared_ptr<T> allocate_shared(const A& a, size_t N, const remove_extent_t<T>& u); // T is U[] template<class T> shared_ptr<T> make_shared(const remove_extent_t<T>& u); // T is U[N] template<class T, class A> shared_ptr<T> allocate_shared(const A& a, const remove_extent_t<T>& u); // T is U[N] template<class T> shared_ptr<T> make_shared_for_overwrite(); // T is not U[] template<class T, class A> shared_ptr<T> allocate_shared_for_overwrite(const A& a); // T is not U[] template<class T> shared_ptr<T> make_shared_for_overwrite(size_t N); // T is U[] template<class T, class A> shared_ptr<T> allocate_shared_for_overwrite(const A& a, size_t N); // T is U[] // shared_ptr comparisons template<class T, class U> bool operator==(const shared_ptr<T>& a, const shared_ptr<U>& b) noexcept; template<class T, class U> strong_ordering operator<=>(const shared_ptr<T>& a, const shared_ptr<U>& b) noexcept; template<class T> bool operator==(const shared_ptr<T>& x, nullptr_t) noexcept; template<class T> strong_ordering operator<=>(const shared_ptr<T>& x, nullptr_t) noexcept; // shared_ptr specialized algorithms template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b) noexcept; // shared_ptr casts template<class T, class U> shared_ptr<T> static_pointer_cast(const shared_ptr<U>& r) noexcept; template<class T, class U> shared_ptr<T> static_pointer_cast(shared_ptr<U>&& r) noexcept; template<class T, class U> shared_ptr<T> dynamic_pointer_cast(const shared_ptr<U>& r) noexcept; template<class T, class U> shared_ptr<T> dynamic_pointer_cast(shared_ptr<U>&& r) noexcept; template<class T, class U> shared_ptr<T> const_pointer_cast(const shared_ptr<U>& r) noexcept; template<class T, class U> shared_ptr<T> const_pointer_cast(shared_ptr<U>&& r) noexcept; template<class T, class U> shared_ptr<T> reinterpret_pointer_cast(const shared_ptr<U>& r) noexcept; template<class T, class U> shared_ptr<T> reinterpret_pointer_cast(shared_ptr<U>&& r) noexcept; // shared_ptr get_deleter template<class D, class T> D* get_deleter(const shared_ptr<T>& p) noexcept; // shared_ptr I/O template<class E, class T, class Y> basic_ostream<E, T>& operator<<(basic_ostream<E, T>& os, const shared_ptr<Y>& p); // class template weak_ptr template<class T> class weak_ptr; // weak_ptr specialized algorithms template<class T> void swap(weak_ptr<T>& a, weak_ptr<T>& b) noexcept; // class template owner_less template<class T = void> struct owner_less; // class template enable_shared_from_this template<class T> class enable_shared_from_this; // hash support template<class T> struct hash; template<class T, class D> struct hash<unique_ptr<T, D>>; template<class T> struct hash<shared_ptr<T>>; // atomic smart pointers template<class T> struct atomic; template<class T> struct atomic<shared_ptr<T>>; template<class T> struct atomic<weak_ptr<T>>; // class template out_ptr_t template<class Smart, class Pointer, class... Args> class out_ptr_t; // function template out_ptr template<class Pointer = void, class Smart, class... Args> auto out_ptr(Smart& s, Args&&... args); // class template inout_ptr_t template<class Smart, class Pointer, class... Args> class inout_ptr_t; // function template inout_ptr template<class Pointer = void, class Smart, class... Args> auto inout_ptr(Smart& s, Args&&... args); } // deprecated namespace std { template<class T> bool atomic_is_lock_free(const shared_ptr<T>* p); template<class T> shared_ptr<T> atomic_load(const shared_ptr<T>* p); template<class T> shared_ptr<T> atomic_load_explicit(const shared_ptr<T>* p, memory_order mo); template<class T> void atomic_store(shared_ptr<T>* p, shared_ptr<T> r); template<class T> void atomic_store_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo); template<class T> shared_ptr<T> atomic_exchange(shared_ptr<T>* p, shared_ptr<T> r); template<class T> shared_ptr<T> atomic_exchange_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo); template<class T> bool atomic_compare_exchange_weak(shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w); template<class T> bool atomic_compare_exchange_strong(shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w); template<class T> bool atomic_compare_exchange_weak_explicit( shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w, memory_order success, memory_order failure); template<class T> bool atomic_compare_exchange_strong_explicit( shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w, memory_order success, memory_order failure); }
[edit] Helper concepts
Note: These names are only for exposition, they are not part of the interface.
template<class I> concept no-throw-input-iterator = // exposition only input_iterator<I> && is_lvalue_reference_v<iter_reference_t<I>> && same_as<remove_cvref_t<iter_reference_t<I>>, iter_value_t<I>>; template<class S, class I> concept no-throw-sentinel-for = sentinel_for<S, I>; // exposition only template<class R> concept no-throw-input-range = // exposition only ranges::range<R> && no-throw-input-iterator<ranges::iterator_t<R>> && no-throw-sentinel-for<ranges::sentinel_t<R>, ranges::iterator_t<R>>; template<class I> concept no-throw-forward-iterator = // exposition only no-throw-input-iterator<I> && forward_iterator<I> && no-throw-sentinel-for<I, I>; template<class R> concept no-throw-forward-range = // exposition only no-throw-input-range<R> && no-throw-forward-iterator<ranges::iterator_t<R>>;
[edit] Class template std::pointer_traits
namespace std { template<class Ptr> struct pointer_traits { using pointer = Ptr; using element_type = /* see description */; using difference_type = /* see description */; template<class U> using rebind = /* see description */; static pointer pointer_to(/* see description */ r); }; template<class T> struct pointer_traits<T*> { using pointer = T*; using element_type = T; using difference_type = ptrdiff_t; template<class U> using rebind = U*; static constexpr pointer pointer_to(/* see description */ r) noexcept; }; }
[edit] Class std::allocator_arg_t
namespace std { struct allocator_arg_t { explicit allocator_arg_t() = default; }; inline constexpr allocator_arg_t allocator_arg{}; }
[edit] Class template std::allocator_traits
namespace std { template<class Alloc> struct allocator_traits { using allocator_type = Alloc; using value_type = typename Alloc::value_type; using pointer = /* see description */; using const_pointer = /* see description */; using void_pointer = /* see description */; using const_void_pointer = /* see description */; using difference_type = /* see description */; using size_type = /* see description */; using propagate_on_container_copy_assignment = /* see description */; using propagate_on_container_move_assignment = /* see description */; using propagate_on_container_swap = /* see description */; using is_always_equal = /* see description */; template<class T> using rebind_alloc = /* see description */; template<class T> using rebind_traits = allocator_traits<rebind_alloc<T>>; static pointer allocate(Alloc& a, size_type n); static pointer allocate(Alloc& a, size_type n, const_void_pointer hint); static constexpr allocation_result<pointer, size_type> allocate_at_least(Alloc& a, size_type n); static void deallocate(Alloc& a, pointer p, size_type n); template<class T, class... Args> static void construct(Alloc& a, T* p, Args&&... args); template<class T> static void destroy(Alloc& a, T* p); static size_type max_size(const Alloc& a) noexcept; static Alloc select_on_container_copy_construction(const Alloc& rhs); }; }
[edit] Class template std::allocator
namespace std { template<class T> class allocator { public: using value_type = T; using size_type = size_t; using difference_type = ptrdiff_t; using propagate_on_container_move_assignment = true_type; constexpr allocator() noexcept; constexpr allocator(const allocator&) noexcept; template<class U> constexpr allocator(const allocator<U>&) noexcept; constexpr ~allocator(); constexpr allocator& operator=(const allocator&) = default; constexpr T* allocate(size_t n); constexpr allocation_result<T*> allocate_at_least(size_t n); constexpr void deallocate(T* p, size_t n); // deprecated using is_always_equal = true_type; }; }
[edit] Class template std::default_delete
namespace std { template<class T> struct default_delete { constexpr default_delete() noexcept = default; template<class U> default_delete(const default_delete<U>&) noexcept; void operator()(T*) const; }; template<class T> struct default_delete<T[]> { constexpr default_delete() noexcept = default; template<class U> default_delete(const default_delete<U[]>&) noexcept; template<class U> void operator()(U* ptr) const; }; }
[edit] Class template std::unique_ptr
namespace std { template<class T, class D = default_delete<T>> class unique_ptr { public: using pointer = /* see description */; using element_type = T; using deleter_type = D; // constructors constexpr unique_ptr() noexcept; explicit unique_ptr(pointer p) noexcept; unique_ptr(pointer p, /* see description */ d1) noexcept; unique_ptr(pointer p, /* see description */ d2) noexcept; unique_ptr(unique_ptr&& u) noexcept; constexpr unique_ptr(nullptr_t) noexcept; template<class U, class E> unique_ptr(unique_ptr<U, E>&& u) noexcept; // destructor ~unique_ptr(); // assignment unique_ptr& operator=(unique_ptr&& u) noexcept; template<class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u) noexcept; unique_ptr& operator=(nullptr_t) noexcept; // observers add_lvalue_reference_t<T> operator*() const noexcept(/* see description */); pointer operator->() const noexcept; pointer get() const noexcept; deleter_type& get_deleter() noexcept; const deleter_type& get_deleter() const noexcept; explicit operator bool() const noexcept; // modifiers pointer release() noexcept; void reset(pointer p = pointer()) noexcept; void swap(unique_ptr& u) noexcept; // disable copy from lvalue unique_ptr(const unique_ptr&) = delete; unique_ptr& operator=(const unique_ptr&) = delete; }; template<class T, class D> class unique_ptr<T[], D> { public: using pointer = /* see description */; using element_type = T; using deleter_type = D; // constructors constexpr unique_ptr() noexcept; template<class U> explicit unique_ptr(U p) noexcept; template<class U> unique_ptr(U p, /* see description */ d) noexcept; template<class U> unique_ptr(U p, /* see description */ d) noexcept; unique_ptr(unique_ptr&& u) noexcept; template<class U, class E> unique_ptr(unique_ptr<U, E>&& u) noexcept; constexpr unique_ptr(nullptr_t) noexcept; // destructor ~unique_ptr(); // assignment unique_ptr& operator=(unique_ptr&& u) noexcept; template<class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u) noexcept; unique_ptr& operator=(nullptr_t) noexcept; // observers T& operator[](size_t i) const; pointer get() const noexcept; deleter_type& get_deleter() noexcept; const deleter_type& get_deleter() const noexcept; explicit operator bool() const noexcept; // modifiers pointer release() noexcept; template<class U> void reset(U p) noexcept; void reset(nullptr_t = nullptr) noexcept; void swap(unique_ptr& u) noexcept; // disable copy from lvalue unique_ptr(const unique_ptr&) = delete; unique_ptr& operator=(const unique_ptr&) = delete; }; }
[edit] Class std::bad_weak_ptr
namespace std { class bad_weak_ptr : public exception { public: bad_weak_ptr() noexcept; }; }
[edit]
namespace std { template<class T> class shared_ptr { public: using element_type = remove_extent_t<T>; using weak_type = weak_ptr<T>; // constructors constexpr shared_ptr() noexcept; constexpr shared_ptr(nullptr_t) noexcept : shared_ptr() { } template<class Y> explicit shared_ptr(Y* p); template<class Y, class D> shared_ptr(Y* p, D d); template<class Y, class D, class A> shared_ptr(Y* p, D d, A a); template<class D> shared_ptr(nullptr_t p, D d); template<class D, class A> shared_ptr(nullptr_t p, D d, A a); template<class Y> shared_ptr(const shared_ptr<Y>& r, element_type* p) noexcept; template<class Y> shared_ptr(shared_ptr<Y>&& r, element_type* p) noexcept; shared_ptr(const shared_ptr& r) noexcept; template<class Y> shared_ptr(const shared_ptr<Y>& r) noexcept; shared_ptr(shared_ptr&& r) noexcept; template<class Y> shared_ptr(shared_ptr<Y>&& r) noexcept; template<class Y> explicit shared_ptr(const weak_ptr<Y>& r); template<class Y, class D> shared_ptr(unique_ptr<Y, D>&& r); // destructor ~shared_ptr(); // assignment shared_ptr& operator=(const shared_ptr& r) noexcept; template<class Y> shared_ptr& operator=(const shared_ptr<Y>& r) noexcept; shared_ptr& operator=(shared_ptr&& r) noexcept; template<class Y> shared_ptr& operator=(shared_ptr<Y>&& r) noexcept; template<class Y, class D> shared_ptr& operator=(unique_ptr<Y, D>&& r); // modifiers void swap(shared_ptr& r) noexcept; void reset() noexcept; template<class Y> void reset(Y* p); template<class Y, class D> void reset(Y* p, D d); template<class Y, class D, class A> void reset(Y* p, D d, A a); // observers element_type* get() const noexcept; T& operator*() const noexcept; T* operator->() const noexcept; element_type& operator[](ptrdiff_t i) const; long use_count() const noexcept; explicit operator bool() const noexcept; template<class U> bool owner_before(const shared_ptr<U>& b) const noexcept; template<class U> bool owner_before(const weak_ptr<U>& b) const noexcept; }; template<class T> shared_ptr(weak_ptr<T>) -> shared_ptr<T>; template<class T, class D> shared_ptr(unique_ptr<T, D>) -> shared_ptr<T>; }
[edit] Class template std::weak_ptr
namespace std { template<class T> class weak_ptr { public: using element_type = remove_extent_t<T>; // constructors constexpr weak_ptr() noexcept; template<class Y> weak_ptr(const shared_ptr<Y>& r) noexcept; weak_ptr(const weak_ptr& r) noexcept; template<class Y> weak_ptr(const weak_ptr<Y>& r) noexcept; weak_ptr(weak_ptr&& r) noexcept; template<class Y> weak_ptr(weak_ptr<Y>&& r) noexcept; // destructor ~weak_ptr(); // assignment weak_ptr& operator=(const weak_ptr& r) noexcept; template<class Y> weak_ptr& operator=(const weak_ptr<Y>& r) noexcept; template<class Y> weak_ptr& operator=(const shared_ptr<Y>& r) noexcept; weak_ptr& operator=(weak_ptr&& r) noexcept; template<class Y> weak_ptr& operator=(weak_ptr<Y>&& r) noexcept; // modifiers void swap(weak_ptr& r) noexcept; void reset() noexcept; // observers long use_count() const noexcept; bool expired() const noexcept; shared_ptr<T> lock() const noexcept; template<class U> bool owner_before(const shared_ptr<U>& b) const noexcept; template<class U> bool owner_before(const weak_ptr<U>& b) const noexcept; }; template<class T> weak_ptr(shared_ptr<T>) -> weak_ptr<T>; }
[edit] Class template std::owner_less
namespace std { template<class T = void> struct owner_less; template<class T> struct owner_less<shared_ptr<T>> { bool operator()(const shared_ptr<T>&, const shared_ptr<T>&) const noexcept; bool operator()(const shared_ptr<T>&, const weak_ptr<T>&) const noexcept; bool operator()(const weak_ptr<T>&, const shared_ptr<T>&) const noexcept; }; template<class T> struct owner_less<weak_ptr<T>> { bool operator()(const weak_ptr<T>&, const weak_ptr<T>&) const noexcept; bool operator()(const shared_ptr<T>&, const weak_ptr<T>&) const noexcept; bool operator()(const weak_ptr<T>&, const shared_ptr<T>&) const noexcept; }; template<> struct owner_less<void> { template<class T, class U> bool operator()(const shared_ptr<T>&, const shared_ptr<U>&) const noexcept; template<class T, class U> bool operator()(const shared_ptr<T>&, const weak_ptr<U>&) const noexcept; template<class T, class U> bool operator()(const weak_ptr<T>&, const shared_ptr<U>&) const noexcept; template<class T, class U> bool operator()(const weak_ptr<T>&, const weak_ptr<U>&) const noexcept; using is_transparent = /* unspecified */; }; }
[edit]
namespace std { template<class T> class enable_shared_from_this { protected: constexpr enable_shared_from_this() noexcept; enable_shared_from_this(const enable_shared_from_this&) noexcept; enable_shared_from_this& operator=(const enable_shared_from_this&) noexcept; ~enable_shared_from_this(); public: shared_ptr<T> shared_from_this(); shared_ptr<T const> shared_from_this() const; weak_ptr<T> weak_from_this() noexcept; weak_ptr<T const> weak_from_this() const noexcept; private: mutable weak_ptr<T> weak_this; // exposition only }; }
[edit]
namespace std { template<class T> struct atomic<shared_ptr<T>> { using value_type = shared_ptr<T>; static constexpr bool is_always_lock_free = /* implementation-defined */; bool is_lock_free() const noexcept; void store(shared_ptr<T> desired, memory_order order = memory_order::seq_cst) noexcept; shared_ptr<T> load(memory_order order = memory_order::seq_cst) const noexcept; operator shared_ptr<T>() const noexcept; shared_ptr<T> exchange(shared_ptr<T> desired, memory_order order = memory_order::seq_cst) noexcept; bool compare_exchange_weak(shared_ptr<T>& expected, shared_ptr<T> desired, memory_order success, memory_order failure) noexcept; bool compare_exchange_strong(shared_ptr<T>& expected, shared_ptr<T> desired, memory_order success, memory_order failure) noexcept; bool compare_exchange_weak(shared_ptr<T>& expected, shared_ptr<T> desired, memory_order order = memory_order::seq_cst) noexcept; bool compare_exchange_strong(shared_ptr<T>& expected, shared_ptr<T> desired, memory_order order = memory_order::seq_cst) noexcept; constexpr atomic() noexcept = default; atomic(shared_ptr<T> desired) noexcept; atomic(const atomic&) = delete; void operator=(const atomic&) = delete; void operator=(shared_ptr<T> desired) noexcept; private: shared_ptr<T> p; // exposition only }; }
[edit] Class template std::atomic's specialization for std::weak_ptr
namespace std { template<class T> struct atomic<weak_ptr<T>> { using value_type = weak_ptr<T>; static constexpr bool is_always_lock_free = /* implementation-defined */; bool is_lock_free() const noexcept; void store(weak_ptr<T> desired, memory_order order = memory_order::seq_cst) noexcept; weak_ptr<T> load(memory_order order = memory_order::seq_cst) const noexcept; operator weak_ptr<T>() const noexcept; weak_ptr<T> exchange(weak_ptr<T> desired, memory_order order = memory_order::seq_cst) noexcept; bool compare_exchange_weak(weak_ptr<T>& expected, weak_ptr<T> desired, memory_order success, memory_order failure) noexcept; bool compare_exchange_strong(weak_ptr<T>& expected, weak_ptr<T> desired, memory_order success, memory_order failure) noexcept; bool compare_exchange_weak(weak_ptr<T>& expected, weak_ptr<T> desired, memory_order order = memory_order::seq_cst) noexcept; bool compare_exchange_strong(weak_ptr<T>& expected, weak_ptr<T> desired, memory_order order = memory_order::seq_cst) noexcept; constexpr atomic() noexcept = default; atomic(weak_ptr<T> desired) noexcept; atomic(const atomic&) = delete; void operator=(const atomic&) = delete; void operator=(weak_ptr<T> desired) noexcept; private: weak_ptr<T> p; // exposition only }; }
[edit] Class template std::out_ptr_t
namespace std { template<class Smart, class Pointer, class... Args> class out_ptr_t { public: explicit out_ptr_t(Smart&, Args...); out_ptr_t(const out_ptr_t&) = delete; ~out_ptr_t(); operator Pointer*() const noexcept; operator void**() const noexcept; private: Smart& s; // exposition only tuple<Args...> a; // exposition only Pointer p; // exposition only }; }
[edit] Class template std::inout_ptr_t
namespace std { template<class Smart, class Pointer, class... Args> class inout_ptr_t { public: explicit inout_ptr_t(Smart&, Args...); inout_ptr_t(const inout_ptr_t&) = delete; ~inout_ptr_t(); operator Pointer*() const noexcept; operator void**() const noexcept; private: Smart& s; // exposition only tuple<Args...> a; // exposition only Pointer p; // exposition only }; }