The header <memory> defines several types and function templates that describe properties of pointers and pointer-like types, manage memory for containers and other template types, and construct multiple objects in uninitialized memory buffers ([pointer.traits]–[specialized.algorithms]). The header also defines the templates unique_ptr, shared_ptr, weak_ptr, and various function templates that operate on objects of these types ([smartptr]).
namespace std {
// [pointer.traits], pointer traits
template <class Ptr> struct pointer_traits;
template <class T> struct pointer_traits<T*>;
// [util.dynamic.safety], pointer safety
enum class pointer_safety { relaxed, preferred, strict };
void declare_reachable(void* p);
template <class T> T* undeclare_reachable(T* p);
void declare_no_pointers(char* p, size_t n);
void undeclare_no_pointers(char* p, size_t n);
pointer_safety get_pointer_safety() noexcept;
// [ptr.align], pointer alignment function
void* align(std::size_t alignment, std::size_t size,
void*& ptr, std::size_t& space);
// [allocator.tag], allocator argument tag
struct allocator_arg_t { };
constexpr allocator_arg_t allocator_arg{};
// [allocator.uses], uses_allocator
template <class T, class Alloc> struct uses_allocator;
// [allocator.traits], allocator traits
template <class Alloc> struct allocator_traits;
// [default.allocator], the default allocator:
template <class T> class allocator;
template <> class allocator<void>;
template <class T, class U>
bool operator==(const allocator<T>&, const allocator<U>&) noexcept;
template <class T, class U>
bool operator!=(const allocator<T>&, const allocator<U>&) noexcept;
// [storage.iterator], raw storage iterator:
template <class OutputIterator, class T> class raw_storage_iterator;
// [temporary.buffer], temporary buffers:
template <class T>
pair<T*,ptrdiff_t> get_temporary_buffer(ptrdiff_t n) noexcept;
template <class T>
void return_temporary_buffer(T* p);
// [specialized.algorithms], specialized algorithms:
template <class T> T* addressof(T& r) noexcept;
template <class InputIterator, class ForwardIterator>
ForwardIterator uninitialized_copy(InputIterator first, InputIterator last,
ForwardIterator result);
template <class InputIterator, class Size, class ForwardIterator>
ForwardIterator uninitialized_copy_n(InputIterator first, Size n,
ForwardIterator result);
template <class ForwardIterator, class T>
void uninitialized_fill(ForwardIterator first, ForwardIterator last,
const T& x);
template <class ForwardIterator, class Size, class T>
ForwardIterator uninitialized_fill_n(ForwardIterator first, Size n, const T& x);
// [unique.ptr] 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);
template <class T> unique_ptr<T> make_unique(size_t n);
template <class T, class... Args> unspecified make_unique(Args&&...) = delete;
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>
bool 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==(nullptr_t, const unique_ptr<T, D>& y) noexcept;
template <class T, class D>
bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept;
template <class T, class D>
bool operator!=(nullptr_t, const unique_ptr<T, D>& y) 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);
// [util.smartptr.weakptr], class bad_weak_ptr:
class bad_weak_ptr;
// [util.smartptr.shared], class template shared_ptr:
template<class T> class shared_ptr;
// [util.smartptr.shared.create], shared_ptr creation
template<class T, class... Args> shared_ptr<T> make_shared(Args&&... args);
template<class T, class A, class... Args>
shared_ptr<T> allocate_shared(const A& a, Args&&... args);
// [util.smartptr.shared.cmp], shared_ptr comparisons:
template<class T, class U>
bool operator==(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
template<class T, class U>
bool operator!=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
template<class T, class U>
bool operator<(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
template<class T, class U>
bool operator>(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
template<class T, class U>
bool operator<=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
template<class T, class U>
bool operator>=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
template <class T>
bool operator==(const shared_ptr<T>& x, nullptr_t) noexcept;
template <class T>
bool operator==(nullptr_t, const shared_ptr<T>& y) noexcept;
template <class T>
bool operator!=(const shared_ptr<T>& x, nullptr_t) noexcept;
template <class T>
bool operator!=(nullptr_t, const shared_ptr<T>& y) noexcept;
template <class T>
bool operator<(const shared_ptr<T>& x, nullptr_t) noexcept;
template <class T>
bool operator<(nullptr_t, const shared_ptr<T>& y) noexcept;
template <class T>
bool operator<=(const shared_ptr<T>& x, nullptr_t) noexcept;
template <class T>
bool operator<=(nullptr_t, const shared_ptr<T>& y) noexcept;
template <class T>
bool operator>(const shared_ptr<T>& x, nullptr_t) noexcept;
template <class T>
bool operator>(nullptr_t, const shared_ptr<T>& y) noexcept;
template <class T>
bool operator>=(const shared_ptr<T>& x, nullptr_t) noexcept;
template <class T>
bool operator>=(nullptr_t, const shared_ptr<T>& y) noexcept;
// [util.smartptr.shared.spec], shared_ptr specialized algorithms:
template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b) noexcept;
// [util.smartptr.shared.cast], shared_ptr casts:
template<class T, class U>
shared_ptr<T> static_pointer_cast(shared_ptr<U> const& r) noexcept;
template<class T, class U>
shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const& r) noexcept;
template<class T, class U>
shared_ptr<T> const_pointer_cast(shared_ptr<U> const& r) noexcept;
// [util.smartptr.getdeleter], shared_ptr get_deleter:
template<class D, class T> D* get_deleter(shared_ptr<T> const& p) noexcept;
// [util.smartptr.shared.io], shared_ptr I/O:
template<class E, class T, class Y>
basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, shared_ptr<Y> const& p);
// [util.smartptr.weak], class template weak_ptr:
template<class T> class weak_ptr;
// [util.smartptr.weak.spec], weak_ptr specialized algorithms:
template<class T> void swap(weak_ptr<T>& a, weak_ptr<T>& b) noexcept;
// [util.smartptr.ownerless], class template owner_less:
template<class T> class owner_less;
// [util.smartptr.enab], class template enable_shared_from_this:
template<class T> class enable_shared_from_this;
// [util.smartptr.shared.atomic], shared_ptr atomic access:
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);
// [util.smartptr.hash] 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> >;
// [depr.auto.ptr], auto_ptr (deprecated)
template <class X> class auto_ptr;
}