Value‐inititalize the specified numElements objects of type allocator_traits<ALLOCATOR>::value_type into the uninitialized array beginning at the specified begin location, using the specified allocator to supply memory (if required). If a constructor throws an exception during this operation, then the destructor is called on any newly constructed elements, leaving the output array in an uninitialized state. The behavior is undefined unless the begin refers to space sufficient to hold numElements.