.. SPDX-FileCopyrightText: 2019-2020 Intel Corporation .. .. SPDX-License-Identifier: CC-BY-4.0

========== Splittable

[req.splittable]

A type is splittable if it has a splitting constructor that allows an instance to be split into two pieces. The splitting constructor takes as arguments a reference to the original object, and a dummy argument of type split, which is defined by the library. The dummy argument distinguishes the splitting constructor from a copy constructor. After the constructor runs, x and the newly constructed object should represent the two pieces of the original x. The library uses splitting constructors in two contexts:

Partitioning a range into two subranges that can be processed concurrently.
Forking a body (function object) into two bodies that can run concurrently.

Types that meet the :doc:Range requirements <range> may additionally define an optional proportional splitting constructor, distinguished by an argument of type :doc:proportional_split Class <../../algorithms/split_tags/proportional_split_cls>.

A type X satisfies Splittable if it meets the following requirements:

Splittable Requirements: Pseudo-Signature, Semantics

.. cpp:function:: X::X(X& x, split)

Split ``x`` into ``x`` and newly constructed object.