void assign(size_type n, el const T& el = T())
This function is a member function of the STL list class and I do not understand the bolded part. I understand the const T& el is a reference to a constant parameter which means I cannot change the value/content of the passed argument + I understand that el = T() means a default parameter so if there is no argument passed in the calling function the el will use the no-argument constructor of the T() type OK. But what make me confused the el at the beginning before the const?!!! so if someone can fill the blank gaps for me I will be grateful :). Thanks in advance.