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account for new traits templates

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[SVN r12468]
This commit is contained in:
Dave Abrahams
2002-01-23 21:04:00 +00:00
parent fc433254dc
commit 9d389aa1e3
1 changed files with 53 additions and 5 deletions
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58
ref.html
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@@ -35,8 +35,9 @@
<p>
The header <a href="../../boost/ref.hpp">boost/ref.hpp</a> defines the class template
<b>boost::reference_wrapper&lt;T&gt;</b> and the two functions <b>boost::ref</b> and
<b>boost::cref</b> that return instances of <b>boost::reference_wrapper&lt;T&gt;</b>.
<b>boost::reference_wrapper&lt;T&gt;</b>, the two functions <b>boost::ref</b> and
<b>boost::cref</b> that return instances of
<b>boost::reference_wrapper&lt;T&gt;</b>, and the two traits classes <b>boost::is_reference_wrapper&lt;T&gt;</b> and <b>boost::unwrap_reference&lt;T&gt;</b>.
</p>
<p>
@@ -62,6 +63,14 @@ where <b>X</b> is the type of <b>x</b>. Similarly, <b>boost::cref(x)</b>
returns a <b>boost::reference_wrapper&lt;X const&gt;(x)</b>.
</p>
<p>The expression <b>boost::is_reference_wrapper&ltT&gt;::value</b> is
<b>true</b> if <b>T</b> is a
<b>reference_wrapper</b>, and <b>false</b> otherwise.
<p>The type-expression <b>boost::unwrap_reference&lt;T&gt;::type</b>
is <b>T::type</b> if <b>T</b> is a
<b>reference_wrapper</b>, <b>T</b> otherwise.
<h2>Interface</h2>
<h3>Synopsis</h3>
@@ -72,6 +81,8 @@ namespace boost
template&lt;class T&gt; class <a href="#reference_wrapper">reference_wrapper</a>;
template&lt;class T&gt; reference_wrapper&lt;T&gt; <a href="#ref">ref</a>(T &amp; t);
template&lt;class T&gt; reference_wrapper&lt;T const&gt; <a href="#cref">cref</a>(T const &amp; t);
template&lt;class T&gt; class is_reference_wrapper&lt;T const&gt;;
template&lt;class T&gt; class unwrap_reference&lt;T const&gt;;
}
</pre>
@@ -81,6 +92,7 @@ namespace boost
template&lt;class T&gt; class reference_wrapper
{
public:
typedef T type;
explicit <a href="#rt_construct">reference_wrapper</a>(T &amp; t);
@@ -92,30 +104,36 @@ public:
<h4><a name="rt_construct">explicit reference_wrapper(T &amp; t)</a></h4>
<blockquote>
<p>
<b>Effects:</b> Constructs a <b>reference_wrapper</b> object that stores a reference to <b>t</b>.
</p>
<p>
<b>Throws:</b> Nothing.
</p>
</blockquote>
<h4><a name="rt_operator">operator T &amp; () const</a></h4>
<blockquote>
<p>
<b>Returns:</b> the stored reference.
</p>
<p>
<b>Throws:</b> Nothing.
</p>
</blockquote>
<h4><a name="rt_get">T &amp; get() const</a></h4>
<blockquote>
<p>
<b>Returns:</b> the stored reference.
</p>
<p>
<b>Throws:</b> Nothing.
</p>
</blockquote>
<h3><a name="ref">ref</a></h3>
@@ -123,12 +141,14 @@ public:
template&lt;class T&gt; reference_wrapper&lt;T&gt; ref(T &amp; t);
</pre>
<blockquote>
<p>
<b>Returns:</b> <tt>reference_wrapper&lt;T&gt;(t)</tt>.
</p>
<p>
<b>Throws:</b> Nothing.
</p>
</blockquote>
<h3><a name="cref">cref</a></h3>
@@ -136,19 +156,47 @@ template&lt;class T&gt; reference_wrapper&lt;T&gt; ref(T &amp; t);
template&lt;class T&gt; reference_wrapper&lt;T const&gt; cref(T const &amp; t);
</pre>
<blockquote>
<p>
<b>Returns:</b> <tt>reference_wrapper&lt;T const&gt;(t)</tt>.
</p>
<p>
<b>Throws:</b> Nothing.
</p>
</blockquote>
<h3><a name="is_reference_wrapper">is_reference_wrapper</a></h3>
<pre>
template&lt;class T&gt; class is_reference_wrapper&lt;T const&gt;
{
public:
static bool value = <i>unspecified</i>;
};
</pre>
Value is <b>true</b> iff <tt>T</tt> is a specialization of <tt>reference_wrapper</tt>.
<h3><a name="unwrap_reference">unwrap_reference</a></h3>
<pre>
template&lt;class T&gt; class unwrap_reference&lt;T const&gt;
{
public:
typedef <i>unspecified</i> type;
};
</pre>
<tt>type</tt> is equivalent to <tt>T::type</tt> if <tt>T</tt> is a specialization of <tt>reference_wrapper</tt>. Otherwise <tt>type</tt> is equivalent to <tt>T</tt>.
<h2>Acknowledgements</h2>
<p>
<b>ref</b> and <b>cref</b> were originally part of the Boost.Tuple library.
They were "promoted to <b>boost::</b> status" because they are generally
useful.
<b>ref</b> and <b>cref</b> were originally part of the Boost.Tuple
library by <a href="../../people/jaakko_jarvi.htm"> Jaakko
J&auml;rvi</a>. They were "promoted to <b>boost::</b> status" by <a
href="../../people/peter_dimov.htm">Peter Dimov</a> because they are
generally useful. <a href="../../people/doug_gregor.html">Douglas
Gregor</a> and <a href="../../people/dave_abrahams.htm">Dave
Abrahams</a> contributed <tt>is_reference_wrapper</tt> and
<tt>unwrap_reference</tt>.
</p>