Assign and Swap

We can assign new elements to an existing container and, if required, swap two containers as well. If we want to assign a container cont2 to another container cont1, we can do so either through copy assignment cont1= cont2 or move assignment cont1= std::move(cont2). In a move assignment, the value of cont2 is copied to cont1 and cont2 becomes empty. A special form of assignment is the one with an initializer list: cont= {1, 2, 3, 4, 5}. In the case of std:array, an initializer list is not possible, hence we use aggregate initialization. The function swap exists in two forms. It is a method cont1(swap(cont2)) and also a function template std::swap(cont1, cont2).