Understanding how to manage versions is crucial when developing a C++ library. Semantic versioning, often called semver, is the most widely adopted standard for versioning libraries and software. It uses a three-part version number: MAJOR.MINOR.PATCH. Each segment of this version number communicates important information to library consumers about the nature of changes in each release.

You increment the MAJOR version when you make incompatible API changes that could break existing code using your library. The MINOR version is incremented when you add new functionality in a backward-compatible manner, such as introducing new functions or classes without changing or removing existing ones. The PATCH version increases when you make backward-compatible bug fixes or small improvements that don’t affect the API or add new features.

Applying semantic versioning correctly allows users of your library to understand whether an update is safe to adopt, or if they need to make changes to their own code. It also helps you, as the author, to communicate the impact of your changes clearly and maintain trust with your users.