# Capacity

The following table provides additional information on the members of this template class.
Member | Description
--- | ---
size_type size() const | Returns: Number of elements in the vector. The result may include elements that are allocated but still under construction by concurrent calls to any of the growth methods.
bool empty() const | Returns: `size()==0`
size_type capacity() const | Returns: Maximum size to which vector can grow without having to allocate more memory. ### Note Unlike an `std::vector`, a `concurrent_vector` does not move existing elements if it allocates more memory.
size_type max_size() const | Returns: The highest possible size of the vector could reach.

Parent topic: concurrent_vector