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<title>Issue 178: Should clog and cerr initially be tied to cout?</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#NAD">NAD</a> status.</em></p>
<h3 id="178"><a href="lwg-closed.html#178">178</a>. Should clog and cerr initially be tied to cout?</h3>
<p><b>Section:</b> 31.4.3 <a href="https://wg21.link/narrow.stream.objects">[narrow.stream.objects]</a> <b>Status:</b> <a href="lwg-active.html#NAD">NAD</a>
 <b>Submitter:</b> Judy Ward <b>Opened:</b> 1999-07-02 <b>Last modified:</b> 2016-01-28</p>
<p><b>Priority: </b>Not Prioritized
</p>
<p><b>View all other</b> <a href="lwg-index.html#narrow.stream.objects">issues</a> in [narrow.stream.objects].</p>
<p><b>View all issues with</b> <a href="lwg-status.html#NAD">NAD</a> status.</p>
<p><b>Discussion:</b></p>
<p>
Section 27.3.1 says &quot;After the object cerr is initialized,
cerr.flags() &amp; unitbuf is nonzero. Its state is otherwise the same as
required for ios_base::init (lib.basic.ios.cons).  It doesn't say
anything about the the state of clog.  So this means that calling
cerr.tie() and clog.tie() should return 0 (see Table 89 for
ios_base::init effects).
</p>
<p>
Neither of the popular standard library implementations
that I tried does this, they both tie cerr and clog
to &amp;cout. I would think that would be what users expect.
</p>


<p><b>Rationale:</b></p>
<p>The standard is clear as written.</p>
<p>27.3.1/5 says that &quot;After the object cerr is initialized, cerr.flags()
&amp; unitbuf is nonzero. Its state is otherwise the same as required for
ios_base::init (27.4.4.1).&quot; Table 89 in 27.4.4.1, which gives the
postconditions of basic_ios::init(), says that tie() is 0. (Other issues correct
ios_base::init to basic_ios::init().)</p>




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