Defined in header <memory> | ||
|---|---|---|
template< class Pointer, class SizeType = std::size_t >
struct allocation_result {
Pointer ptr;
SizeType count;
};
| (since C++23) |
allocation_result specializations are returned from the allocate_at_least member function of appropriate Allocator types (e.g. std::allocator::allocate_at_least) and std::allocator_traits::allocate_at_least.
Every specialization of allocation_result has no base classes or declared members other than ptr and count, thus it is suitable for aggregate initialization and structured binding.
| Pointer | - | typically std::allocator_traits<Alloc>::pointer, where Alloc is an Allocator type |
| SizeType | - | typically std::allocator_traits<Alloc>::size_type, where Alloc is an Allocator type |
| ptr
(C++23) | typically used for the address of the first element in the storage allocated by allocate_at_least (public member object) |
| count
(C++23) | typically used for the actual number of elements in the storage allocated by allocate_at_least (public member object) |
Pointer and SizeType are a pointer to an object type and std::make_unsigned_t<std::ptrdiff_t> (which is almost always same as std::size_t) by default.
| Feature-test macro | Value | Std |
|---|---|---|
__cpp_lib_allocate_at_least | 202302L | (C++23) |
|
(C++23) | allocates uninitialized storage at least as large as requested size (public member function of std::allocator<T>) |
|
[static] (C++23) | allocates storage at least as large as the requested size via an allocator (public static member function of std::allocator_traits<Alloc>) |
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