https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119409
--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> --- Similarly: include/std/chrono:# include <sstream> include/std/chrono:# include <string> include/std/chrono:# include <vector> include/std/flat_map:#include <functional> // not_fn include/std/flat_map:#include <ranges> // views::zip include/std/flat_map:#include <vector> include/std/flat_set:#include <functional> // not_fn include/std/flat_set:#include <vector> Currently not_fn is only in <functional> but we could split that header up into smaller pieces. And we'll probably want to split up <ranges> at some point, so that we can use individual adaptors in library internals without having to compile all of them every time.