+ void push_back(const GradientCPoint cpoint) { cpoints.push_back(cpoint); }
+ iterator erase(iterator iter) { return cpoints.erase(iter); }
+ bool empty()const { return cpoints.empty(); }
+ size_t size()const { return cpoints.size(); }
+
+ iterator begin() { return cpoints.begin(); }
+ iterator end() { return cpoints.end(); }
+ reverse_iterator rbegin() { return cpoints.rbegin(); }
+ reverse_iterator rend() { return cpoints.rend(); }
+ const_iterator begin()const { return cpoints.begin(); }
+ const_iterator end()const { return cpoints.end(); }
+ const_reverse_iterator rbegin()const { return cpoints.rbegin(); }
+ const_reverse_iterator rend()const { return cpoints.rend(); }
+