| CMAKE_Swift_LANGUAGE_VERSION | |
| ---------------------------- | |
| Set to the Swift language version number. If not set, the oldest legacy | |
| version known to be available in the host Xcode version is assumed: | |
| * Swift ``4.0`` for Xcode 10.2 and above. | |
| * Swift ``3.0`` for Xcode 8.3 and above. | |
| * Swift ``2.3`` for Xcode 8.2 and below. |