I remember new proejct template generated by earlier versions of Xcode had explicit PCH support. But recent versions dropped this feature. It seems Xcode has an implicit PCH cache. I do not know how this cache works.
I actually want the old explicit way of creating PCH. For example, I want to include <CloudKit/CloudKit> in PCH so that it is available to all files in a project. Is there any way to accomplish this using the new implicit cache?
Precompiled Header Files are discouraged in favor of modules. You can still configure your project to use a PCH file if you prefer. Create a header file with the .PCH extension and edit the Prefix Header [GCC_PREFIX_HEADER] build setting for your target to be the path to the file you jsut created, relative to your project.