When functionality is already available in class libraries used, such as standard C++ library, STL or Boost, it is a waste of time and resources to build the functionality your own. In contrast to the standard C library, the standard C++ library contains a large number of generic algorithms and container types. So, use a std::list rather than crafting your own, etc.

Adherence to design guidelines can make it infeasible to use the standard C++ library directly. Consistency considerations, see [STY#021], can also lead to not following this rule.