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Section: 19.14 [function.objects] Status: NAD Submitter: BSI Opened: 2010-08-25 Last modified: 2016-02-10
Priority: Not Prioritized
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The function templates hash, less and equal_to are important customization points for user-defined types to be supported by several standard containers. These are accessed through the <functional> header which has grown significantly larger in C++0x, exposing many more facilities than a user is likely to need through there own header, simply to declare the necessary specialization. There should be a smaller header available for users to make the necessary customization.
[ Resolution proposed by ballot comment ]
Provide a tiny forwarding header for important functor types in the <functional> header that a user may want to specialize. This should contain the template declaration for equal_to, hash and less.
[ Rapperswill summary ]
Alisdair: Would recommend NAD unless someone takes the issue.
Daniel: Volunteers to write a paper for this.
[ 2010-11-07 Daniel provides a paper available on the Batavia document list ]
[ 2010 Batavia: ]
Closed as NAD - the consensus was that forwarding headers such as <iosfwd> do not bring the expected benefits, and are not widely used (to the surprise of some active users in the room!). Without real experience reporting a benefit, there is no further interest in pursuing this issue as an extension - hence NAD rather than NAD Future.
No consensus to make a change
See paper "Forwarding <functional> functor templates" on the Batavia LWG document list