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2747. Possibly redundantstd::move in [alg.foreach]

Section: 26.6.5[alg.foreach]Status:C++17Submitter: Jonathan WakelyOpened: 2016-07-15Last modified: 2017-07-30

Priority:0

View otheractive issues in [alg.foreach].

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Discussion:

26.6.5[alg.foreach] p3 saysReturns:std::move(f).

[class.copy] says that sincef is a function parameter overload resolution to select the constructor for the return value is first performed as if for an rvalue, so thestd::move is redundant.

It could be argued that it isn't entirely redundant, because it says that implementations can't do something slightly different like return an lvalue reference that is bound tof, which would prevent it being treated as an rvalue. We should discuss it.

[2016-07 Chicago]

Monday: P0 - tentatively ready

Proposed resolution:

This wording is relative to N4606.

1. Change 26.6.5[alg.foreach] as indicated:

   template<class InputIterator, class Function>  Function for_each(InputIterator first, InputIterator last, Function f);

   […]

   -3-Returns:std::move(f).

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