CMAKECONFIGURATIONTYPES

CMAKE_CONFIGURATION_TYPES is a cached CMake variable that lists the build configurations available for a multi-configuration generator, such as Visual Studio or Xcode. It is meaningful only when the generator supports multiple configurations in a single project. The value is typically a semicolon-separated list of configuration names, for example Debug;Release;MinSizeRel;RelWithDebInfo.

In contrast to multi-configuration generators, single-configuration generators (such as Unix Makefiles or Ninja) do not rely on this variable to select a configuration. For those generators, the active configuration is chosen at configure time via CMAKE_BUILD_TYPE and only one configuration is produced per build directory.

Setting CMAKE_CONFIGURATION_TYPES is most useful when you want to declare the configurations that a project can produce under a multi-configuration generator. You can set it before configuring the project, usually as a cache entry. For example, you might set: set(CMAKE_CONFIGURATION_TYPES "Debug;Release;RelWithDebInfo;MinSizeRel" CACHE STRING "" FORCE). The exact effect depends on the generator; some environments ignore it if it is not applicable.

Behavior with common generators: Visual Studio reads CMAKE_CONFIGURATION_TYPES to determine the available project configurations and allows switching among them in the IDE. Xcode similarly exposes multiple configurations. For other generators, this variable may be ignored, and the build system will rely on its default configuration behavior.

In practice, use CMAKE_CONFIGURATION_TYPES to document and enable the intended configurations for multi-configuration workflows, while recognizing that single-configuration pipelines rely on CMAKE_BUILD_TYPE.