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<div class="title">Comparison using relational operator zypp::Rel.</div> </div>
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Classes</h2></td></tr>
<tr class="memitem:"><td class="memItemLeft" align="right" valign="top">struct  </td><td class="memItemRight" valign="bottom"><a class="el" href="structzypp_1_1Compare.html">zypp::Compare< Tp ></a></td></tr>
<tr class="memdesc:"><td class="mdescLeft"> </td><td class="mdescRight">General compare functor returning <code>-1, 0, 1</code>. <a href="structzypp_1_1Compare.html#details">More...</a><br /></td></tr>
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<tr class="memitem:"><td class="memItemLeft" align="right" valign="top">struct  </td><td class="memItemRight" valign="bottom"><a class="el" href="structzypp_1_1CompareBy.html">zypp::CompareBy< Tp, TCompare ></a></td></tr>
<tr class="memdesc:"><td class="mdescLeft"> </td><td class="mdescRight">Functor to compare two elements by <a class="el" href="structzypp_1_1Rel.html">Rel</a> based on a general <em>TCompare</em> functor. <a href="structzypp_1_1CompareBy.html#details">More...</a><br /></td></tr>
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<tr class="memitem:"><td class="memItemLeft" align="right" valign="top">struct  </td><td class="memItemRight" valign="bottom"><a class="el" href="structzypp_1_1CompareByEQ.html">zypp::CompareByEQ< Tp, TCompare ></a></td></tr>
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<tr class="memitem:"><td class="memItemLeft" align="right" valign="top">struct  </td><td class="memItemRight" valign="bottom"><a class="el" href="structzypp_1_1CompareByNE.html">zypp::CompareByNE< Tp, TCompare ></a></td></tr>
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<tr class="memitem:"><td class="memItemLeft" align="right" valign="top">struct  </td><td class="memItemRight" valign="bottom"><a class="el" href="structzypp_1_1CompareByLT.html">zypp::CompareByLT< Tp, TCompare ></a></td></tr>
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<tr class="memitem:"><td class="memItemLeft" align="right" valign="top">struct  </td><td class="memItemRight" valign="bottom"><a class="el" href="structzypp_1_1CompareByLE.html">zypp::CompareByLE< Tp, TCompare ></a></td></tr>
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<tr class="memitem:"><td class="memItemLeft" align="right" valign="top">struct  </td><td class="memItemRight" valign="bottom"><a class="el" href="structzypp_1_1CompareByGT.html">zypp::CompareByGT< Tp, TCompare ></a></td></tr>
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<tr class="memitem:"><td class="memItemLeft" align="right" valign="top">struct  </td><td class="memItemRight" valign="bottom"><a class="el" href="structzypp_1_1CompareByGE.html">zypp::CompareByGE< Tp, TCompare ></a></td></tr>
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<tr class="memitem:"><td class="memItemLeft" align="right" valign="top">struct  </td><td class="memItemRight" valign="bottom"><a class="el" href="structzypp_1_1CompareByANY.html">zypp::CompareByANY< Tp, TCompare ></a></td></tr>
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<tr class="memitem:"><td class="memItemLeft" align="right" valign="top">struct  </td><td class="memItemRight" valign="bottom"><a class="el" href="structzypp_1_1CompareByNONE.html">zypp::CompareByNONE< Tp, TCompare ></a></td></tr>
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Functions</h2></td></tr>
<tr class="memitem:ga4245cf6b48eb6c19ed7e18589d4d1b9a"><td class="memTemplParams" colspan="2">template<class Tp , class TCompare > </td></tr>
<tr class="memitem:ga4245cf6b48eb6c19ed7e18589d4d1b9a"><td class="memTemplItemLeft" align="right" valign="top"><a class="el" href="classbool.html">bool</a> </td><td class="memTemplItemRight" valign="bottom"><a class="el" href="group__RelCompare.html#ga4245cf6b48eb6c19ed7e18589d4d1b9a">zypp::compareByRel</a> (<a class="el" href="structzypp_1_1Rel.html">Rel</a> op, const Tp &lhs, const Tp &rhs, TCompare compare)</td></tr>
<tr class="memdesc:ga4245cf6b48eb6c19ed7e18589d4d1b9a"><td class="mdescLeft"> </td><td class="mdescRight">Comparison of two elements using relational operator <em>op</em>. <a href="group__RelCompare.html#ga4245cf6b48eb6c19ed7e18589d4d1b9a">More...</a><br /></td></tr>
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<tr class="memitem:ga116631ef189082c4dd7e2479e422af8a"><td class="memTemplParams" colspan="2">template<class Tp > </td></tr>
<tr class="memitem:ga116631ef189082c4dd7e2479e422af8a"><td class="memTemplItemLeft" align="right" valign="top"><a class="el" href="classbool.html">bool</a> </td><td class="memTemplItemRight" valign="bottom"><a class="el" href="group__RelCompare.html#ga116631ef189082c4dd7e2479e422af8a">zypp::compareByRel</a> (<a class="el" href="structzypp_1_1Rel.html">Rel</a> op, const Tp &lhs, const Tp &rhs)</td></tr>
<tr class="memdesc:ga116631ef189082c4dd7e2479e422af8a"><td class="mdescLeft"> </td><td class="mdescRight"><a class="el" href="group__RelCompare.html#ga4245cf6b48eb6c19ed7e18589d4d1b9a">compareByRel</a> convenience using Compare<Tp> as general compare functor. <a href="group__RelCompare.html#ga116631ef189082c4dd7e2479e422af8a">More...</a><br /></td></tr>
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<a name="details" id="details"></a><h2 class="groupheader">Detailed Description</h2>
<p>Take a class like <a class="el" href="classzypp_1_1Edition.html" title="Edition represents [epoch:]version[-release]">zypp::Edition</a>. Editions are comaprable. You can compare them lexicographical, or according to their version and release values, or match them (i.e. taking empty version or release values as wildcard).</p>
<p>No matter which way is appropriate within a certain context. You need functions to compare, and may want to use classes like <a class="el" href="structzypp_1_1Range.html">zypp::Range</a>, based on the desired comparison.</p>
<p>All the class has to do, is providing a general comparison method (preferably static) </p><div class="fragment"><div class="line"><span class="comment">// Compare two elements returning -1, 0, 1</span></div><div class="line"><span class="comment">// if the elemants compare <,==,>.</span></div><div class="line"><span class="keyword">static</span> <span class="keywordtype">int</span> compare( <span class="keyword">const</span> Tp & lhs, <span class="keyword">const</span> Tp & rhs );</div></div><!-- fragment --><p><code><a class="el" href="structzypp_1_1Compare.html" title="General compare functor returning -1, 0, 1.">Compare</a><Tp></code> provides a functor wrapping <code>compare</code>. In case the general comparison method is named differently, the class, or you, have to provide an approriate functor.</p>
<p><code>compareByRel</code> then compares two elements using a certain operator and general comparison method. </p><div class="fragment"><div class="line"><a class="code" href="group__RelCompare.html#ga4245cf6b48eb6c19ed7e18589d4d1b9a">compareByRel</a>( <a class="code" href="structzypp_1_1Rel.html#acf87bde5e682c492c9db9cf48135e265">Rel::EQ</a>, lhs, rhs, <a class="code" href="classzypp_1_1IdStringType.html#aec4135e45049399405a16a8891d080c6">Edition::compare</a> );</div><div class="line"><a class="code" href="group__RelCompare.html#ga4245cf6b48eb6c19ed7e18589d4d1b9a">compareByRel</a>( <a class="code" href="structzypp_1_1Rel.html#acf87bde5e682c492c9db9cf48135e265">Rel::EQ</a>, lhs, rhs, <a class="code" href="classzypp_1_1Edition.html#a035179d5ccc3316823fa92bbca552539">Edition::match</a> );</div><div class="line"><a class="code" href="group__RelCompare.html#ga4245cf6b48eb6c19ed7e18589d4d1b9a">compareByRel</a>( <a class="code" href="structzypp_1_1Rel.html#acf87bde5e682c492c9db9cf48135e265">Rel::EQ</a>, lhs, rhs ); <span class="comment">// defaults to Compare<Edition></span></div><div class="line"> <span class="comment">// thus Edition::compare</span></div></div><!-- fragment --><p>Furthermore a bunch of functors using a certain opertator is defined. All templated by type and general comparison method (defaults to <a class="el" href="structzypp_1_1Compare.html" title="General compare functor returning -1, 0, 1.">Compare</a><Tp>). </p><div class="fragment"><div class="line"><span class="comment">// Editions sets use lexicographical order per default:</span></div><div class="line">std::set<Edition></div><div class="line"></div><div class="line"><span class="comment">// An Edition set using Edition::compare as order:</span></div><div class="line">std::set<Edition,CompareByLT<Edition> >;</div><div class="line"></div><div class="line"><span class="comment">// Edition::match is not transitive, thus not an appropriate</span></div><div class="line"><span class="comment">// order relation for std::set or std::map.</span></div></div><!-- fragment --><p>Classes like zypp:<a class="el" href="structzypp_1_1Range.html">Range</a> are templated by by type and general comparison method as well. Thus you may use <a class="el" href="classzypp_1_1Edition.html" title="Edition represents [epoch:]version[-release]">Edition</a> ranges based on <a class="el" href="classzypp_1_1Edition.html#a4d4a488c5b9cd9a4a0554c0e7f13d2d7" title="compare functor.">Edition::Compare</a>, as well as ranges based on <a class="el" href="structzypp_1_1Edition_1_1Match.html" title="match functor.">Edition::Match</a> (<a class="el" href="classzypp_1_1Edition.html" title="Edition represents [epoch:]version[-release]">Edition</a> provides these two functors).</p>
<p>Again: Everything a class has to provide is the general comparison method. Comparison functors and ranges are then immediately available. </p>
<h2 class="groupheader">Function Documentation</h2>
<a id="ga4245cf6b48eb6c19ed7e18589d4d1b9a"></a>
<h2 class="memtitle"><span class="permalink"><a href="#ga4245cf6b48eb6c19ed7e18589d4d1b9a">◆ </a></span>compareByRel() <span class="overload">[1/2]</span></h2>
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<td class="memname"><a class="el" href="classbool.html">bool</a> zypp::compareByRel </td>
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<p>Comparison of two elements using relational operator <em>op</em>. </p>
<p>Expects <em>TCompare</em> to be a binary operator returning <code>-1, 0, 1</code> if the elemants compare <code><,==,></code>. </p><div class="fragment"><div class="line"><span class="comment">// Signature of compare function or functor:</span></div><div class="line"><span class="keywordtype">int</span> compare( <span class="keyword">const</span> Tp & lhs, <span class="keyword">const</span> Tp & rhs );</div></div><!-- fragment --> <ul>
<li>If <em>op</em> is <a class="el" href="structzypp_1_1Rel.html#ab9b87f803fe36f4f05a6280e65498d2a">Rel::ANY</a>, the expression is always <code>true</code>. </li>
<li>If <em>op</em> is <a class="el" href="structzypp_1_1Rel.html#a982a7e193215b0050d8dd5b5d906992e">Rel::NONE</a>, the expression is always <code>false</code>. </li>
<li>Otherwise the expression is evaluated using <em>compare</em>. </li>
</ul>
<p class="definition">Definition at line <a class="el" href="RelCompare_8h_source.html#l00108">108</a> of file <a class="el" href="RelCompare_8h_source.html">RelCompare.h</a>.</p>
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<h2 class="memtitle"><span class="permalink"><a href="#ga116631ef189082c4dd7e2479e422af8a">◆ </a></span>compareByRel() <span class="overload">[2/2]</span></h2>
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<p><a class="el" href="group__RelCompare.html#ga4245cf6b48eb6c19ed7e18589d4d1b9a">compareByRel</a> convenience using Compare<Tp> as general compare functor. </p>
<p class="definition">Definition at line <a class="el" href="RelCompare_8h_source.html#l00144">144</a> of file <a class="el" href="RelCompare_8h_source.html">RelCompare.h</a>.</p>
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