Your own code is as foreign as a third party library to a developer who hasn't been part of the writing process. Third party libraries which have a handful or

Your own code is as foreign as a third party library to a developer who hasn't been part of the writing process. Third party libraries which have a handful or more users are generally speaking relatively bug-free for standard use cases. Third party libraries are generally a productivity win for languages which have decent build systems, which is most of them notably excluding C and C++.