std::pmr::polymorphic_allocator<T>::allocate
Since C++20
[[nodiscard]] T* allocate( std::size_t n );
Since C++17, Until C++20
T* allocate( std::size_t n );
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
A pointer to the allocated storage.
Exceptions
Throws std::bad_array_new_length if n > std::numeric_limits<std::size_t>::max() / sizeof(T);
may also throw any exceptions thrown by the call to resource()->allocate.
Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 3038 | C++17 | allocate might allocate storage of wrong size | throws length_error instead |
| LWG 3237 | C++17 | the exception thrown by allocate was inconsistent with std::allocator::allocate | made consistent |