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<title>Issue 649: Several typos in regex_token_iterator constructors</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_Editorial">NAD Editorial</a> status.</em></p>
<h3 id="649"><a href="lwg-closed.html#649">649</a>. Several typos in regex_token_iterator constructors</h3>
<p><b>Section:</b> 28.6.11.2.2 <a href="https://wg21.link/re.tokiter.cnstr">[re.tokiter.cnstr]</a> <b>Status:</b> <a href="lwg-active.html#NAD_Editorial">NAD Editorial</a>
 <b>Submitter:</b> Daniel Kr&uuml;gler <b>Opened:</b> 2007-03-03 <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#re.tokiter.cnstr">issues</a> in [re.tokiter.cnstr].</p>
<p><b>View all issues with</b> <a href="lwg-status.html#NAD Editorial">NAD Editorial</a> status.</p>
<p><b>Discussion:</b></p>
<p>
In 28.6.11.2.2 <a href="https://wg21.link/re.tokiter.cnstr">[re.tokiter.cnstr]</a>/1+2 both the constructor declaration
and the following text shows some obvious typos:
</p>
<p>
1) The third constructor form is written as
</p>
<blockquote><pre>
template &lt;std::size_t N&gt;
  regex_token_iterator(BidirectionalIterator a, BidirectionalIterator b, 
                       const regex_type&amp; re, 
                       const int (&amp;submatches)[R], 
                       regex_constants::match_flag_type m = 
                         regex_constants::match_default);
</pre></blockquote>

<p>
where the dimensions of submatches are specified by an
unknown value R, which should be N.
</p>
<p>
2) Paragraph 2 of the same section says in its last sentence:
</p>

<blockquote><p>
The third constructor initializes the member <code>subs</code> to hold a
copy of the sequence of integer values pointed to by the iterator range
<code>[&amp;submatches, &amp;submatches + R)</code>.
</p></blockquote>

<p>
where again R must be replaced by N.
</p>

<p>
3) Paragraph 3 of the same section says in its first sentence:
</p>

<blockquote><p>
Each constructor then sets <code>N</code> to <code>0</code>, and
<code>position</code> to <code>position_iterator(a, b, re, f)</code>.
</p></blockquote>

<p>
where a non-existing parameter "f" is mentioned, which must be
replaced
by the parameter "m".
</p>


<p id="res-649"><b>Proposed resolution:</b></p>
<p>
Change 28.6.11.2.2 <a href="https://wg21.link/re.tokiter.cnstr">[re.tokiter.cnstr]</a>/1:
</p>
<blockquote><pre>
template &lt;std::size_t N&gt;
  regex_token_iterator(BidirectionalIterator a, BidirectionalIterator b, 
                       const regex_type&amp; re, 
                       const int (&amp;submatches)[<del>R</del> <ins>N</ins>], 
                       regex_constants::match_flag_type m = 
                         regex_constants::match_default);
</pre></blockquote>

<p>
Change 28.6.11.2.2 <a href="https://wg21.link/re.tokiter.cnstr">[re.tokiter.cnstr]</a>/2:
</p>

<blockquote><p>
<i>Effects:</i> The first constructor initializes the member
<code>subs</code> to hold the single value <code>submatch</code>. The second
constructor initializes the member <code>subs</code> to hold a copy of the
argument <code>submatches</code>. The third constructor initializes the
member <code>subs</code> to hold a copy of the sequence of integer values
pointed to by the iterator range <code>[&amp;submatches, &amp;submatches +
<del>R</del> <ins>N</ins>)</code>.
</p></blockquote>

<p>
Change 28.6.11.2.2 <a href="https://wg21.link/re.tokiter.cnstr">[re.tokiter.cnstr]</a>/3:
</p>

<blockquote><p>
Each constructor then sets <code>N</code> to <code>0</code>, and
<code>position</code> to <code>position_iterator(a, b, re, <del>f</del>
<ins>m</ins>)</code>. If <code>position</code> is not an end-of-sequence
iterator the constructor sets <code>result</code> to the address of the
current match. Otherwise if any of the values stored in <code>subs</code> is
equal to <code>-1</code> the constructor sets <code>*this</code> to a suffix
iterator that points to the range <code>[a, b)</code>, otherwise the
constructor sets <code>*this</code> to an end-of-sequence iterator.
</p></blockquote>






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