Author: Linux Manual

std::pmr::polymorphic_allocator<T>::allocate – std::pmr::polymorphic_allocator<T>::allocate Synopsis T* allocate( std::size_t n ); (since C++17)                                              (until C++20) [[nodiscard]] T* allocate( std::size_t n ); (since C++20) Allocates storage for n objects of type T using the underlying memory resource. Equivalent to return static_cast<T*>(resource()->allocate(n * sizeof(T), alignof(T))); . Parameters n – the number of objects to allocate storage for Return value…

std::pmr::polymorphic_allocator – std::pmr::polymorphic_allocator Synopsis template< class T > (since C++17) class polymorphic_allocator; (until C++20) template< class T = std::byte > (since C++20) class polymorphic_allocator; The class template std::pmr::polymorphic_allocator is an Allocator whose allocation behavior depends on the memory resource it is constructed with. Thus, different instances of polymorphic_allocator can exhibit entirely different allocation behavior. This…

std::pmr::operator==,std::pmr::operator!= – std::pmr::operator==,std::pmr::operator!= Synopsis bool operator==(const std::pmr::memory_resource &a, (1)(since C++ 17) const std::pmr::memory_resource &b) noexcept; bool operator!=(const std::pmr::memory_resource &a, (2)(since C++ 17) const std::pmr::memory_resource &b) noexcept; Compares the memory_resources a and b for equality. Two memory_resources compare equal if and only if memory allocated from one memory_resource can be deallocated from the other and vice…

std::pmr::null_memory_resource – std::pmr::null_memory_resource Synopsis Defined in header <memory_resource> std::pmr::memory_resource* null_memory_resource() noexcept; (since C++17) Returns a pointer to a memory_resource that doesn’t perform any allocation. Return value Returns a pointer p to a static storage duration object of a type derived from std::pmr::memory_resource, with the following properties: * its allocate() function always throws std::bad_alloc; * its…

std::pmr::new_delete_resource – std::pmr::new_delete_resource Synopsis Defined in header <memory_resource> std::pmr::memory_resource* new_delete_resource() noexcept; (since C++17) Returns a pointer to a memory_resource that uses the global operator_new and operator_delete to allocate memory. Return value Returns a pointer p to a static storage duration object of a type derived from std::pmr::memory_resource, with the following properties: * its allocate() function…

std::pmr::monotonic_buffer_resource::upstream_resource – std::pmr::monotonic_buffer_resource::upstream_resource Synopsis std::pmr::memory_resource* upstream_resource() const; (since C++17) Returns a pointer to the upstream memory resource. This is the same value as the upstream argument passed to the constructor of this object. See also               Constructs a monotonic_buffer_resource constructor (public member function)

std::pmr::monotonic_buffer_resource::release – std::pmr::monotonic_buffer_resource::release Synopsis void release(); (since C++ 17) Releases all allocated memory by calling the deallocate function on the upstream memory resource as necessary. Memory is released back to the upstream resource even if deallocate has not been called for some of the allocated blocks. See also            deallocates memory deallocate (public member function of…

std::pmr::monotonic_buffer_resource::~monotonic_buffer_resource – std::pmr::monotonic_buffer_resource::~monotonic_buffer_resource Synopsis virtual ~monotonic_buffer_resource(); (since C++17) Destroys a monotonic_buffer_resource. Deallocates all memory owned by this resource by calling this->release(). See also         Release all allocated memory release (public member function)

std::pmr::monotonic_buffer_resource::do_is_equal – std::pmr::monotonic_buffer_resource::do_is_equal Synopsis virtual bool do_is_equal(const std::pmr::memory_resource& other) const noexcept; (since C++17) Compare *this with other for identity – memory allocated using a monotonic_buffer_resource can only be deallocated using that same resource. Return value this == &other Defect report The following behavior-changing defect reports were applied retroactively to previously published C++ standards. DR Applied…

std::pmr::monotonic_buffer_resource::do_deallocate – std::pmr::monotonic_buffer_resource::do_deallocate Synopsis virtual void do_deallocate(void* p, std::size_t bytes, std::size_t alignment); (since C++17) This function has no effect. Memory used by a monotonic_buffer_resource, as its name indicates, increases monotonically until the resource is destroyed. Exceptions Throws nothing. See also               deallocates memory deallocate (public member function of std::pmr::memory_resource) do_deallocate deallocates memory               (virtual private member function…

std::pmr::monotonic_buffer_resource::do_allocate – std::pmr::monotonic_buffer_resource::do_allocate Synopsis virtual void* do_allocate(std::size_t bytes, std::size_t alignment); (since C++17) Allocates storage. If the current buffer has sufficient unused space to fit a block with the specified size and alignment, allocates the return block from the current buffer. Otherwise, this function allocates a new buffer by calling upstream_resource()->allocate(n, m), where n is not…

std::pmr::monotonic_buffer_resource – std::pmr::monotonic_buffer_resource Synopsis Defined in header <memory_resource> class monotonic_buffer_resource : public std::pmr::memory_resource; (since C++17) The class std::pmr::monotonic_buffer_resource is a special-purpose memory resource class that releases the allocated memory only when the resource is destroyed. It is intended for very fast memory allocations in situations where memory is used to build up a few objects…

std::pmr::memory_resource::memory_resource – std::pmr::memory_resource::memory_resource Synopsis memory_resource() = default; (1)(since C++ 17)(implicitly declared) memory_resource(const memory_resource &) = default; (2)(since C++ 17)(implicitly declared) 1) Implicitly declared default constructor. 2) Implicitly declared copy constructor.

std::pmr::memory_resource::is_equal – std::pmr::memory_resource::is_equal Synopsis bool is_equal(const memory_resource& other) const noexcept; (since C++17) Compares *this for equality with other. Two memory_resources compare equal if and only if memory allocated from one memory_resource can be deallocated from the other and vice versa. Equivalent to return do_is_equal(other);. See also do_is_equal compare for equality with another memory_resource             (virtual private…

std::pmr::memory_resource::do_is_equal – std::pmr::memory_resource::do_is_equal Synopsis virtual bool do_is_equal(const std::pmr::memory_resource &other) const noexcept = 0; (since C++ 17) Compares *this for equality with other. Two memory_resources compare equal if and only if memory allocated from one memory_resource can be deallocated from the other and vice versa. Notes The most-derived type of other may not match the most…

std::pmr::memory_resource::do_deallocate – std::pmr::memory_resource::do_deallocate Synopsis virtual void do_deallocate(void *p, std::size_t bytes, std::size_t alignment) = 0; (since C++ 17) Deallocates the storage pointed to by p. p must have been returned by a prior call to allocate(bytes, alignment) on a memory_resource that compares equal to *this, and the storage it points to must not yet have been…

std::pmr::memory_resource::do_allocate – std::pmr::memory_resource::do_allocate Synopsis virtual void *do_allocate(std::size_t bytes, std::size_t alignment) = 0; (since C++ 17) Allocates storage with a size of at least bytes bytes, aligned to the specified alignment. alignment shall be a power of two. Exceptions Throws an exception if storage of the requested size and alignment cannot be obtained. Defect reports The…

std::pmr::memory_resource::deallocate – std::pmr::memory_resource::deallocate Synopsis void deallocate(void *p, std::size_t bytes, (since C++ 17) std::size_t alignment = alignof(std::max_align_t)); Deallocates the storage pointed to by p. p shall have been returned by a prior call to allocate(bytes, alignment) on a memory_resource that compares equal to *this, and the storage it points to shall not yet have been deallocated….

std::pmr::memory_resource::allocate – std::pmr::memory_resource::allocate Synopsis void *allocate(std::size_t bytes, (since C++ 17) std::size_t alignment = alignof(std::max_align_t)); (until C++ 20) [[nodiscard]] void *allocate(std::size_t bytes, (since C++ 20) std::size_t alignment = alignof(std::max_align_t)); Allocates storage with a size of at least bytes bytes.The returned storage is aligned to the specified alignment if such alignment is supported, and to alignof(std::max_align_t) otherwise….

std::pmr::memory_resource – std::pmr::memory_resource Synopsis Defined in header <memory_resource> class memory_resource; (since C++17) The class std::pmr::memory_resource is an abstract interface to an unbounded set of classes encapsulating memory resources. Member functions constructor constructs a new memory_resource                       (public member function) (implicitly declared) destructor destructs an memory_resource                       (virtual public member function) [virtual] operator= Implicitly declared copy assignment operator…