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pair [C++ Reference]
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<h2><a name="pair" id="pair">pair</a></h2>
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<p>
Syntax:
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<pre class="c code c++" style="font-family:monospace;"> pair<span class="br0">(</span><span class="br0">)</span><span class="sy0">;</span>
pair<span class="br0">(</span> <span class="kw4">const</span> T1 <span class="sy0">&</span>a<span class="sy0">,</span> <span class="kw4">const</span> T2 <span class="sy0">&</span>b <span class="br0">)</span><span class="sy0">;</span></pre>
<p>
The pair struct is a way to store two pieces of heterogeneous data.
</p>
<p>
These data may be accessed using the <code>first</code> and <code>second</code> fields of a pair.
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<p>
Pairs may be tested for equality with the <code>==</code> operator. The <code><</code> operator is also defined for pairs; given two pairs <code>x</code> and <code>y</code>, the <code><</code> operator returns:
</p>
<pre class="c code c++" style="font-family:monospace;">x.<span class="me1">first</span> <span class="sy0"><</span> y.<span class="me1">first</span> <span class="sy0">||</span> <span class="br0">(</span><span class="br0">(</span>y.<span class="me1">first</span> <span class="sy0">==</span> x.<span class="me1">first</span><span class="br0">)</span> <span class="sy0">&&</span> x.<span class="me1">second</span> <span class="sy0"><</span> y.<span class="me1">second</span><span class="br0">)</span></pre>
<p>
The <a href="../../stl/utility/make_pair.html" class="wikilink1" title="stl:utility:make_pair">make_pair</a> function can be used as a shortcut when creating pairs to avoid explicitly specifying the types for the two pieces of data.
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Related: <a href="../../stl/utility/make_pair.html" class="wikilink1" title="stl:utility:make_pair">make_pair</a>
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