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<title>Issue 527: tr1::bind has lost its Throws clause</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="527"><a href="lwg-defects.html#527">527</a>. <code>tr1::bind</code> has lost its Throws clause</h3>
<p><b>Section:</b> 22.10.15.4 <a href="https://wg21.link/func.bind.bind">[func.bind.bind]</a>, 99 [tr.func.bind.bind] <b>Status:</b> <a href="lwg-active.html#CD1">CD1</a>
 <b>Submitter:</b> Peter Dimov <b>Opened:</b> 2005-10-01 <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#func.bind.bind">issues</a> in [func.bind.bind].</p>
<p><b>View all issues with</b> <a href="lwg-status.html#CD1">CD1</a> status.</p>
<p><b>Discussion:</b></p>
<p>
The original bind proposal gives the guarantee that <code>tr1::bind(f, t1, ..., tN)</code> 
does not throw when the copy constructors of <code>f, t1, ..., tN</code> don't.
</p>

<p>
This guarantee is not present in the final version of TR1.
</p>

<p>
I'm pretty certain that we never removed it on purpose. Editorial omission? :-)
</p>

<p><i>[
Berlin: not quite editorial, needs proposed wording.
]</i></p>

<p><i>[
Batavia:  Doug to translate wording to variadic templates.
]</i></p>


<p><i>[
Toronto:  We agree but aren't quite happy with the wording.  The "t"'s no
longer refer to anything.  Alan to provide improved wording.
]</i></p>



<p><i>[
Pre-Bellevue:  Alisdair provided wording.
]</i></p>


<p>
TR1 proposed resolution:
</p>

<blockquote>
<p>
In 99 [tr.func.bind.bind], add a new paragraph after p2:
</p>
<blockquote><p>
<i>Throws:</i> Nothing unless one of the copy constructors of <code>f, t1, t2, ..., tN</code>
throws an exception.
</p></blockquote>

<p>
Add a new paragraph after p4:
</p>
<blockquote><p>
<i>Throws:</i> nothing unless one of the copy constructors of <code>f, t1, t2, ..., tN</code>
throws an exception.
</p></blockquote>

</blockquote>



<p id="res-527"><b>Proposed resolution:</b></p>
<p>
In 22.10.15.4 <a href="https://wg21.link/func.bind.bind">[func.bind.bind]</a>, add a new paragraph after p2:
</p>

<blockquote><p>
<i>Throws:</i> Nothing unless the copy constructor of <code>F</code> or of one of the types
in the <code>BoundArgs...</code> pack expansion throws an exception. 
</p></blockquote>

<p>
In 22.10.15.4 <a href="https://wg21.link/func.bind.bind">[func.bind.bind]</a>, add a new paragraph after p4:
</p>

<blockquote><p>
<i>Throws:</i> Nothing unless the copy constructor of <code>F</code> or of one of the types
in the <code>BoundArgs...</code> pack expansion throws an exception. 
</p></blockquote>






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