std::allocation_result - cppreference.com (original) (raw)
| | | | | --------------------------------------------------------------------------------------------------------------- | | ------------- | | template< class Pointer, class SizeType = std::size_t > struct allocation_result; | | (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.
[edit] Template parameters
[edit] Data members
| Member name | Definition |
|---|---|
| a pointer of type Pointer which is typically used for the address of the first element in the storage allocated by allocate_at_least (public member object) | |
| a value of type SizeType which is typically used for the actual number of elements in the storage allocated by allocate_at_least (public member object) |
[edit] Notes
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 | Feature |
|---|---|---|---|
| __cpp_lib_allocate_at_least | 202302L | (C++23) | Size-feedback in the Allocator interface |
[edit] Example
[edit] See also
| | allocates uninitialized storage at least as large as requested size (public member function of std::allocator) [edit] | | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | | allocates storage at least as large as the requested size via an allocator (public static member function of std::allocator_traits) [edit] |