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<td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>QPair Class Reference</h1>
<p>The QPair class is a value-based template class that provides a pair of elements.
<a href="#details">More...</a>
<p><tt>#include <<a href="qpair-h.html">qpair.h</a>></tt>
<p><a href="qpair-members.html">List of all member functions.</a>
<h2>Public Members</h2>
<ul>
<li><div class=fn>typedef T1 <a href="#first_type"><b>first_type</b></a></div></li>
<li><div class=fn>typedef T2 <a href="#second_type"><b>second_type</b></a></div></li>
<li><div class=fn><a href="#QPair"><b>QPair</b></a> ()</div></li>
<li><div class=fn><a href="#QPair-2"><b>QPair</b></a> ( const T1 & t1, const T2 & t2 )</div></li>
</ul>
<hr><a name="details"></a><h2>Detailed Description</h2>
The QPair class is a value-based template class that provides a pair of elements.
<p>
<p> QPair is a Qt implementation of an STL-like pair. It
can be used in your application if the standard pair<> is not
available.
<p> QPair<T1, T2> defines a template instance to create
a pair of values that contains two values of type T1 and T2. Please
note that QPair does not store pointers to the two elements; it
holds a copy of every member. This is why these
kinds of classes are called <em>value based</em>. If you're interested
in <em>pointer based</em> classes see, for example, <a href="qptrlist.html">QPtrList</a> and <a href="qdict.html">QDict</a>.
<p> QPair holds one copy of type T1 and one copy of type T2, but does
not provide iterators to access these elements. Rather, the two
elements (<tt>first</tt> and <tt>second</tt>) are public member variables of the
pair. QPair owns the contained elements. For more relaxed ownership
semantics, see <a href="qptrcollection.html">QPtrCollection</a> and friends which are pointer-based
containers.
<p> Some classes cannot be used within a QPair: for example, all classes
derived from <a href="qobject.html">QObject</a> and thus all classes that implement widgets.
Only "values" can be used in a QPair. To qualify as a value the class
must provide:
<p> <ul>
<li> A copy constructor
<li> An assignment operator
<li> A constructor that takes no argument
</ul>
<p> Note that C++ defaults to field-by-field assignment operators and
copy constructors if no explicit version is supplied. In many cases
this is sufficient.
<p> QPair uses an STL-like syntax to manipulate and address the objects
it contains. See the <a href="qtl.html">QTL documentation</a> for
more information.
<p> Functions that need to return two values can use a QPair. The
<a href="qtl.html#qMakePair">qMakePair()</a> convenience function
makes it easy to create QPair objects.
<p>See also <a href="qtl.html">Qt Template Library Classes</a>, <a href="shared.html">Implicitly and Explicitly Shared Classes</a> and <a href="tools.html">Non-GUI Classes</a>.
<hr><h2>Member Type Documentation</h2>
<h3 class=fn><a name="first_type"></a>QPair::first_type</h3>
The type of the first element in the pair.
<h3 class=fn><a name="second_type"></a>QPair::second_type</h3>
The type of the second element in the pair.
<hr><h2>Member Function Documentation</h2>
<h3 class=fn><a name="QPair"></a>QPair::QPair ()
</h3>
Constructs an empty pair. The <tt>first</tt> and <tt>second</tt> elements
are default constructed.
<h3 class=fn><a name="QPair-2"></a>QPair::QPair ( const T1 & t1, const T2 & t2 )
</h3>
Constructs a pair and initializes the <tt>first</tt> element with <em>t1</em>
and the <tt>second</tt> element with <em>t2</em>.
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