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<title>Issue 415: behavior of std::ws</title>
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<p><em>This page is a snapshot from the LWG issues list, see the <a href="lwg-active.html">Library Active Issues List</a> for more information and the meaning of <a href="lwg-active.html#CD1">CD1</a> status.</em></p>
<h3 id="415"><a href="lwg-defects.html#415">415</a>. behavior of std::ws</h3>
<p><b>Section:</b> 31.7.5.5 <a href="https://wg21.link/istream.manip">[istream.manip]</a> <b>Status:</b> <a href="lwg-active.html#CD1">CD1</a>
 <b>Submitter:</b> Martin Sebor <b>Opened:</b> 2003-09-18 <b>Last modified:</b> 2016-01-28</p>
<p><b>Priority: </b>Not Prioritized
</p>
<p><b>View all issues with</b> <a href="lwg-status.html#CD1">CD1</a> status.</p>
<p><b>Discussion:</b></p>
<p>
According to 27.6.1.4, the ws() manipulator is not required to construct
the sentry object. The manipulator is also not a member function so the
text in 27.6.1, p1 through 4 that describes the exception policy for
istream member functions does not apply. That seems inconsistent with
the rest of extractors and all the other input functions (i.e., ws will
not cause a tied stream to be flushed before extraction, it doesn't check
the stream's exceptions or catch exceptions thrown during input, and it
doesn't affect the stream's gcount).
</p>


<p id="res-415"><b>Proposed resolution:</b></p>
<p>
Add to 31.7.5.5 <a href="https://wg21.link/istream.manip">[istream.manip]</a>, immediately before the first sentence
of paragraph 1, the following text:
</p>

    <blockquote><p>
    Behaves as an unformatted input function (as described in
    27.6.1.3, paragraph 1), except that it does not count the number
    of characters extracted and does not affect the value returned by
    subsequent calls to is.gcount(). After constructing a sentry
    object...  
    </p></blockquote>

<p><i>[Post-Kona: Martin provided wording]</i></p>






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