Hi Sam,
it seems to me that your user-facing option is not actually Boolean, but
tri-state: On vs. Off vs. Use_default. So I would represent it accordingly:
present the user with a string variable (with suitable STRINGS property
https://cmake.org/cmake/help/latest/prop_cache/STRINGS.html), and
Hi all!
I have a project with some options that have different defaults depending
on the configuration used to build the project. For example, support for a
certain (easy to support, but relatively uncommon) file format should be on
by default, except when building in the MinSizeRel
