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4463. Change wording to 'model' from 'subsumes' in [algorithms.parallel.user]

Section: 26.3.2 [algorithms.parallel.user] Status: Immediate Submitter: Ruslan Arutyunyan Opened: 2025-11-07 Last modified: 2025-11-07

Priority: Not Prioritized

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Discussion:

“Subsumes” word does not work here because regular_invocable and invocable subsume each other.

Proposed change: Say that the type is required to model regular_invocable.

[Kona 2025-11-07; approved by LWG. Status changed: New → Immediate.]

Proposed resolution:

This wording is relative to N5014.

1. Modify 26.3.2 [algorithms.parallel.user], as indicated:

   -1- Unless otherwise specified, invocable objects passed into parallel algorithms as objects of a type denoted by a template parameter named Predicate, BinaryPredicate, Compare, UnaryOperation, BinaryOperation, BinaryOperation1, BinaryOperation2, BinaryDivideOp, or constrained by a concept whose semantic requirements include that subsumes the type models regular_invocable and the operators used by the analogous overloads to these parallel algorithms that are formed by an invocation with the specified default predicate or operation (where applicable) shall not directly or indirectly modify objects via their arguments, nor shall they rely on the identity of the provided objects.