That's a tricky question. Large C++ codebases often have a lot of "legacy" that does not necessarily reflect the best practices. A couple of years ago I wrote

That's a tricky question. Large C++ codebases often have a lot of "legacy" that does not necessarily reflect the best practices. A couple of years ago I wrote a text-editor to have a realistic example of what I consider a nice modern architecture using immutable data-structures. In the README there is also a link to a talk where I cover some of the design and structure: https://github.com/arximboldi/ewig https://github.com/arximboldi/ewig Libraries that it uses: https://github.com/arximboldi/immer https://github.com/arximboldi/immer https://github.com/arximboldi/lager https://github.com/arximboldi/lager