Description : The emplace() member inserts an element at the top of the stack and constructs the element in place from the arguments provided. This can be more efficient than push in certain situations and avoid temporaries. emplace() effectively forwards its arguments to a constructor that is placed at the top of the stack.
Example:
std::stack<std::string> st;
// Add some strings to the stack
st.emplace("C++ world");
st.emplace("Hello");
std::cout << st.top();
st.pop();
std::cout << ", " << st.top() << std::endl;