Apple is indeed patenting Swift features

Prior Art would take care of that if Apple had not gotten a patent on Optional Chaining (the Google patents page for US9952841B2, which was the only result I could find for the number given by @ebup, reads to me more like the whole concept of Swift, but I may be misunderstanding).

From a quick search (IANAL, also not from US, so salt to taste), I could also not find a consensus on whether the patent grant in the Apache license extended to derivative works and unrelated works. This StackExchange answer makes it sound like it does not, which as I read it could mean that Apple could still require a patent license if another project wanted to incorporate Optional Chaining.

Here is the patent grant section of the license:

3. Grant of Patent License . Subject to the terms and conditions of this License, each Contributor hereby grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable (except as stated in this section) patent license to make, have made, use, offer to sell, sell, import, and otherwise transfer the Work, where such license applies only to those patent claims licensable by such Contributor that are necessarily infringed by their Contribution(s) alone or by combination of their Contribution(s) with the Work to which such Contribution(s) was submitted. If You institute patent litigation against any entity (including a cross-claim or counterclaim in a lawsuit) alleging that the Work or a Contribution incorporated within the Work constitutes direct or contributory patent infringement, then any patent licenses granted to You under this License for that Work shall terminate as of the date such litigation is filed.