Movatterモバイル変換

This page is a snapshot from the LWG issues list, see theLibrary Active Issues List for more information and the meaning ofCD1 status.

664.do_unshift forcodecvt<char, char, mbstate_t>

Section: 28.3.4.2.5.3[locale.codecvt.virtuals]Status:CD1Submitter: Thomas PlumOpened: 2007-04-16Last modified: 2016-01-28

Priority:Not Prioritized

View otheractive issues in [locale.codecvt.virtuals].

View all otherissues in [locale.codecvt.virtuals].

View all issues withCD1 status.

Discussion:

28.3.4.2.5.3[locale.codecvt.virtuals], para 7 says (regardingdo_unshift):

Effects: Places characters starting at to that should be appended toterminate a sequence when the currentstateT is given bystate.²³⁷⁾ Stores no more than(to_limit -to) destination elements, and leaves theto_nextpointer pointing one beyond the last element successfully stored.codecvt<char, char, mbstate_t> stores no characters.

The following objection has been raised:

Since the C++ Standard permits a nontrivial conversion for the requiredinstantiations ofcodecvt, it is overly restrictive to say thatdo_unshift must store no characters and returnnoconv.

[Plum ref _222152Y50]

Proposed resolution:

Change 28.3.4.2.5.3[locale.codecvt.virtuals], p7:

Effects: Places characters starting atto that should beappended to terminate a sequence when the currentstateT isgiven by state.²³⁷⁾ Stores no more than (to_limit -to)destination elements, and leaves theto_next pointer pointing onebeyond the last element successfully stored.codecvt<char, char,mbstate_t> stores no characters.