HPX V2.1.0 (TBD)#

Breaking changes#

The execution-policy overloads of hpx::ranges::all_of, any_of, none_of, count, count_if, contains, equal, starts_with, ends_with, contains_subrange, is_partitioned, and lexicographical_compare now follow P3179. Range arguments must model std::ranges::random_access_range and std::ranges::sized_range; iterator/sentinel arguments must model std::random_access_iterator and std::sized_sentinel_for. Overloads without an execution policy retain their existing constraints. In particular, the contains iterator/sentinel overload requires both types to model std::input_iterator.
The P3179-aligned overloads use standard ranges callable defaults and pass predicates and projections by value. Their concept-based constraints may produce different diagnostics than the previous iterator static_assert checks. Code that explicitly names HPX’s former default callable types may need to use the corresponding std::ranges callable types.
The count and contains task-policy overloads store an owned copy of copyable search values in their asynchronous operation state. Noncopyable lvalues, including arrays, are borrowed and must remain valid until the returned future becomes ready, even if the future is discarded.

A peer fenced by failure detection is now removed from the registry, so snapshot_peers() no longer lists it; its fence is kept (PR #7922). That removal no longer drops a peer that came back with a new epoch while it was being removed, which left the peer unmonitored, and the eviction a terminal lifecycle notification schedules no longer removes a peer that started a newer epoch meanwhile (Issue #7924, PR #8027).