Assign and Swap
You can assign new elements to existing containers or swap two containers. For the assignment of a container cont2 to a container cont, there exists the copy assignment cont= cont2 and the move assignment cont= std::move(cont2). A special form of assignment is the one with an initialiser list: cont= {1, 2, 3, 4, 5}. That’s not possible for std::array, but you can instead use the aggregate initialisation. The function swap exists in two forms. You have it as a method cont(swap(cont2)) or as a function template std::swap(cont, cont2).
// containerAssignmentAndSwap.cpp
...
#include <set>...
std::set<int> set1{0, 1, 2, 3, 4, 5};
std::set<int> set2{6, 7, 8, 9};
for (auto s: set1) std::cout << s << " "; // 0 1 2 3 4 5
for (auto s: set2) std::cout << s << " "; // 6 7 8 9
set1= set2;
for (auto s: set1) std::cout << s << " "; // 6 7 8 9
for (auto s: set2) std...