Method add

internal/concurrentqueue_internal_debug.h:62–67

		void swap(DebugFreeList& other) { std::swap(head, other.head); }
		
		inline void add(N* node)
		{
			DebugLock lock(mutex);
			node->freeListNext = head;
			head = node;
		}
		
		inline N* try_get()
		{