SharonIV0X86/CinderPeak — reverse-engineered prompt

Build me a modern C++ graph library called CinderPeak. I want it to let someone create directed, undirected, or mixed graphs, add vertices and edges, update edge data, and quickly check simple things like how many vertices and edges are in the graph. It should work with normal types like int, but also let users plug in their own vertex and edge structs, including weighted and unweighted edges.

Please make the API clean and beginner friendly, with efficient internal storage options like adjacency lists, adjacency matrices, and CSR or COO style storage where it makes sense. Keep performance and thread safety in mind, but don’t make the public API feel complicated.

Set it up as a C++17 or C++20 project with a CMake build, solid unit tests, a few clear examples, and documentation that explains installation and basic usage. The end result should feel like a small polished open source library someone could actually include in their own graph or network projects.