Partition

ℹ️ What is a partition?
A partition of a set is a decomposition of a set in subsets so that each element of the set is precisely in one subset. The subsets are defined in C++ by a unary predicate so that the members of the first subset fulfill the predicate. The remaining elements are in the second subset.

C++ offers a few functions for dealing with partitions. All of them need a unary predicate pre. std::partition and std::stable_partition partition a range and returns the partition point. With std::partition_point you can get the partition point of a partition. Afterwards you can check the partition with std::is_partitioned or copy it with std::partition_copy.

Checks if the range is partitioned: