CXXGraph: The Header-Only C++ Graph Library You Should Know About

I recently spent a week studying the CXXGraph codebase top-to-bottom. What I found is a library that makes consistently good architectural decisions — and a few that are worth talking about openly. This post is for the C++ developer who either needs a graph library today, or who wants to learn how a production-quality header-only library is structured. Why another graph library? The usual answer to "I need graphs in C++" is Boost.Graph. If you have never opened the Boost.Graph documentation, congratulations — you have lived a fuller life than I have. The abstraction model is powerful, correct, and almost completely impenetrable to anyone who did not write it. Concepts, property maps, bundled properties, vertex and edge descriptors: by the time you understand the machinery you could have written the algorithm yourself. CXXGraph takes the opposite bet: developer experience first, zero external dependencies, modern C++17 throughout. You drop a single #include "CXXGraph/CXXGraph.hpp" into