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Section: 22.14.6.7 [format.context] Status: C++23 Submitter: Casey Carter Opened: 2021-06-08 Last modified: 2023-11-22
Priority: Not Prioritized
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Discussion:
LWG 3539 fixed copies of potentially-move-only iterators in the format_to and
vformat_to overloads, but missed the fact that member functions of basic_format_context
are specified to copy iterators as well. In particular, 22.14.6.7 [format.context] states:
iterator out();-7- Returns:
out_.void advance_to(iterator it);-8- Effects: Equivalent to:
out_ = it;
both of which appear to require copyability.
[2021-06-23; Reflector poll]
Set status to Tentatively Ready after six votes in favour during reflector poll.
[2021-10-14 Approved at October 2021 virtual plenary. Status changed: Voting → WP.]
Proposed resolution:
This wording is relative to N4885.
Modify 22.14.6.7 [format.context] as indicated:
iterator out();-7-
Returns:Effects: Equivalent to:out_.return std::move(out_);void advance_to(iterator it);-8- Effects: Equivalent to:
out_ = std::move(it);