llvm-project

20667a67 - [libc++] Include range access headers in `<optional>` only since C++26 (#214688)

[libc++] Include range access headers in `<optional>` only since C++26 (#214688) Inclusions of internal range access headers address LWG4131 which patches P3168R2 "Give `std::optional` Range Support". As P3168R2 is certainly a new feature in C++26, these includes are unnecessary in old modes. It was reported that these increased the size of `<optional>` by ~8%, so probably it is better to avoid such cost in old modes.