slibs | Single file libraries for C/C++

Generator expressions are usable only for some properties and some variables, so they could be evaluated at the end of configuration stage to a values, which depends from the build type. Such behavior cannot be achieved with plain if because multi-configuration CMake generators (like Visual Studio) read a CMakeLists.txt once but create several configurations.

Generator expressions are usable also for the commands which sets these properties and variables.

Every possible usage of generator expressions is explicitly stated in the documentation for a command/property/variable which supports them.

Documentation for the command set_target_properties doesn't describe usage of generator expressions, so this command simply doesn't support them.

Actually, one can pass to that command a generator expression as a property's value. In that case the command will just assign that value to the corresponded property. It is dependent from the property whether the generator expression will be resolved when evaluate the property after the configuration.

But neither the name of the target not the name of the property cannot be a generator expression.

For conditionally set properties for a target, use plain if: