cmake / 3.12.4 / variable / cmake_swift_language_version.html /

CMAKE_Swift_LANGUAGE_VERSION

Set to the Swift language version number. If not set, the legacy “2.3” version is assumed.

© 2000–2019 Kitware, Inc. and Contributors
Licensed under the BSD 3-clause License.
https://cmake.org/cmake/help/v3.12/variable/CMAKE_Swift_LANGUAGE_VERSION.html