TeDDy which stands for "Templated Decision Diagram library" is a C++ library for the creation and manipulation of Decision Diagrams. Its source code, installation guide, and short description with examples are available on Github. This page contains its documentation and thanks to Unicode also its mascot "U+1F9F8" 🧸.
The main page of the Doxygen documentation for the library is available here. All of the library functions for diagram manipulation are implemented in the diagram_manager class. You are probably here to see that one. As with the diagram manipulation, the library functions for reliability analysis are implemented in the reliability_manager class. Last but not least, there is the diagram class which represents the diagram and is used in both aforementioned classes.
TeDDy's Github page contains a brief description of its implementation in terms of algorithms and data structures. There are a couple of other aspects concerning the programming side that I think might be interesting (at least at the time of writing). I will try to describe some of them here, in the C++ section.