I've drawn up UML (or close-to-UML) class diagrams in the past while trying to understand large, unfamiliar C++ codebases while new to a project. While they we

I've drawn up UML (or close-to-UML) class diagrams in the past while trying to understand large, unfamiliar C++ codebases while new to a project. While they were painful to make (especially by hand), they provided a nice map that could be pointed to while asking questions in meetings with those who knew the code. The making of the diagrams were an exercise that definitely gave me a better understanding of the class relationships that I would have taken longer to learn otherwise. Beyond the initial exercise, I didn't find them very useful in the longer term.