code:

23.2.2.3 list modifiers [lib.list.modifiers]
iterator insert(iterator position, const T& x);
void insert(iterator position, size_type n, const T& x);
template <class InputIterator>
void insert(iterator position, InputIterator first,
InputIterator last);
void push_front(const T& x);
void push_back(const T& x);
1 Notes: Does not affect the validity of iterators and references. If an exception is thrown there are no
effects.
2 Complexity: Insertion of a single element into a list takes constant time and exactly one call to the copy
constructor of T. Insertion of multiple elements into a list is linear in the number of elements inserted,
and the number of calls to the copy constructor of T is exactly equal to the number of elements inserted.
iterator erase(iterator position);
iterator erase(iterator first, iterator last);
void pop_front();
void pop_back();
void clear();
3 Effects: Invalidates only the iterators and references to the erased elements.
4 Throws: Nothing.
5 Complexity: Erasing a single element is a constant time operation with a single call to the destructor of T.
Erasing a range in a list is linear time in the size of the range and the number of calls to the destructor of
type T is exactly equal to the size of the range.