The code for this recipe is available at https://github.com/dev-cafe/cmake-cookbook/tree/v1.0/chapter-07/recipe-06. The recipe is valid with CMake version 3.5 (and higher) and has been tested on GNU/Linux, macOS, and Windows.
Deprecation is an important mechanism in the development of an evolving project to signal to developers that a function or macro or a variable will be removed or replaced at some point in the future. For a certain period, the function, macro, or variable will continue being accessible but signal a warning, which eventually can be elevated to an error.
