143 lines
15 KiB
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143 lines
15 KiB
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<title>operator==,!=,<,<=>(std::error_condition)</title>
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<h1 id="firstHeading" class="firstHeading">operator==,!=,<,<=><span style="font-size:0.7em; line-height:130%">(std::error_condition)</span></h1>
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<div id="contentSub"><span class="subpages">< <a href="cpp.html">cpp</a>‎ | <a href="cpp-error.html">error</a>‎ | <a href="cpp-error-error_condition.html">error condition</a></span></div>
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<div>定义于头文件 <code><a href="cpp-header-system_error.html"><system_error></a></code></div>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw4">bool</span> operator<span class="sy1">==</span><span class="br0">(</span> <span class="kw4">const</span> <a href="cpp-error-error_condition.html"><span class="kw874">std::<span class="me2">error_condition</span></span></a><span class="sy3">&</span> lhs,<br />
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<span class="kw4">const</span> <a href="cpp-error-error_condition.html"><span class="kw874">std::<span class="me2">error_condition</span></span></a><span class="sy3">&</span> rhs <span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span></span></div>
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<td>(1)</td>
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<td><span class="t-mark-rev t-since-cxx11">(C++11 起)</span></td>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw4">bool</span> operator<span class="sy3">!</span><span class="sy1">=</span><span class="br0">(</span> <span class="kw4">const</span> <a href="cpp-error-error_condition.html"><span class="kw874">std::<span class="me2">error_condition</span></span></a><span class="sy3">&</span> lhs,<br />
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<span class="kw4">const</span> <a href="cpp-error-error_condition.html"><span class="kw874">std::<span class="me2">error_condition</span></span></a><span class="sy3">&</span> rhs <span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span></span></div>
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<td>(2)</td>
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<td><span class="t-mark-rev t-since-cxx11">(C++11 起)</span><br />
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<span class="t-mark-rev t-until-cxx20">(C++20 前)</span></td>
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<tr class="t-dcl t-since-cxx11 t-until-cxx20">
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<div><span class="mw-geshi cpp source-cpp"><span class="kw4">bool</span> operator<span class="sy1"><</span><span class="br0">(</span> <span class="kw4">const</span> <a href="cpp-error-error_condition.html"><span class="kw874">std::<span class="me2">error_condition</span></span></a><span class="sy3">&</span> lhs,<br />
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<span class="kw4">const</span> <a href="cpp-error-error_condition.html"><span class="kw874">std::<span class="me2">error_condition</span></span></a><span class="sy3">&</span> rhs <span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span></span></div>
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<td>(3)</td>
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<td><span class="t-mark-rev t-since-cxx11">(C++11 起)</span><br />
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<span class="t-mark-rev t-until-cxx20">(C++20 前)</span></td>
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<div><span class="mw-geshi cpp source-cpp">std<span class="sy4">::</span><span class="me2">strong_ordering</span> operator<span class="sy1"><=></span><span class="br0">(</span> <span class="kw4">const</span> <a href="cpp-error-error_condition.html"><span class="kw874">std::<span class="me2">error_condition</span></span></a><span class="sy3">&</span> lhs,<br />
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<span class="kw4">const</span> <a href="cpp-error-error_condition.html"><span class="kw874">std::<span class="me2">error_condition</span></span></a><span class="sy3">&</span> rhs <span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span></span></div>
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<td>(4)</td>
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<td><span class="t-mark-rev t-since-cxx20">(C++20 起)</span></td>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw4">bool</span> operator<span class="sy1">==</span><span class="br0">(</span> <span class="kw4">const</span> <a href="cpp-error-error_code.html"><span class="kw877">std::<span class="me2">error_code</span></span></a><span class="sy3">&</span> code,<br />
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<span class="kw4">const</span> <a href="cpp-error-error_condition.html"><span class="kw874">std::<span class="me2">error_condition</span></span></a><span class="sy3">&</span> cond <span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span></span></div>
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<td>(5)</td>
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<td><span class="t-mark-rev t-since-cxx11">(C++11 起)</span></td>
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<tr class="t-dcl t-since-cxx11 t-until-cxx20">
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<div><span class="mw-geshi cpp source-cpp"><span class="kw4">bool</span> operator<span class="sy1">==</span><span class="br0">(</span> <span class="kw4">const</span> <a href="cpp-error-error_condition.html"><span class="kw874">std::<span class="me2">error_condition</span></span></a><span class="sy3">&</span> cond,<br />
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<span class="kw4">const</span> <a href="cpp-error-error_code.html"><span class="kw877">std::<span class="me2">error_code</span></span></a><span class="sy3">&</span> code <span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span></span></div>
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<td>(5)</td>
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<td><span class="t-mark-rev t-since-cxx11">(C++11 起)</span><br />
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<span class="t-mark-rev t-until-cxx20">(C++20 前)</span></td>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw4">bool</span> operator<span class="sy3">!</span><span class="sy1">=</span><span class="br0">(</span> <span class="kw4">const</span> <a href="cpp-error-error_code.html"><span class="kw877">std::<span class="me2">error_code</span></span></a><span class="sy3">&</span> code,<br />
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<span class="kw4">const</span> <a href="cpp-error-error_condition.html"><span class="kw874">std::<span class="me2">error_condition</span></span></a><span class="sy3">&</span> cond <span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span></span></div>
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<td>(6)</td>
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<td><span class="t-mark-rev t-since-cxx11">(C++11 起)</span><br />
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<span class="t-mark-rev t-until-cxx20">(C++20 前)</span></td>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw4">bool</span> operator<span class="sy3">!</span><span class="sy1">=</span><span class="br0">(</span> <span class="kw4">const</span> <a href="cpp-error-error_condition.html"><span class="kw874">std::<span class="me2">error_condition</span></span></a><span class="sy3">&</span> cond,<br />
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<span class="kw4">const</span> <a href="cpp-error-error_code.html"><span class="kw877">std::<span class="me2">error_code</span></span></a><span class="sy3">&</span> code <span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span></span></div>
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<td>(6)</td>
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<td><span class="t-mark-rev t-since-cxx11">(C++11 起)</span><br />
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<span class="t-mark-rev t-until-cxx20">(C++20 前)</span></td>
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<p>比较二个错误条件。</p>
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<div class="t-li1"><span class="t-li">1)</span> 检查 <code>lhs</code> 与 <code>rhs</code> 是否相等。</div>
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<div class="t-li1"><span class="t-li">2)</span> 检查 <code>lhs</code> 与 <code>rhs</code> 是否不相等。</div>
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<div class="t-li1"><span class="t-li">3)</span> 检查 <code>lhs</code> 是否<i>小于</i> <code>rhs</code> 。</div>
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<div class="t-li1"><span class="t-li">4)</span> 获得 <code>lhs</code> 与 <code>rhs</code> 的三路比较结果。</div>
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<div class="t-li1"><span class="t-li">5)</span> 检查 <code>code</code> 是否为 <code>cond</code> 的语义匹配。</div>
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<div class="t-li1"><span class="t-li">6)</span> 检查 <code>code</code> 是否不是 <code>cond</code> 的语义匹配。</div>
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<p><code><</code>、 <code><=</code>、 <code>></code>、 <code>>=</code> 及 <code>!=</code> 运算符分别从 <code>operator<=></code> 与 <code>operator==</code> <a href="cpp-language-operators.html#.E5.85.B3.E7.B3.BB.E8.BF.90.E7.AE.97.E7.AC.A6">合成</a>。</p>
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<td><span class="t-mark-rev t-since-cxx20">(C++20 起)</span></td>
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<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">参数</span></h3>
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<td>lhs, rhs, cond</td>
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<td>-</td>
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<td>要比较的错误条件</td>
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<tr class="t-par">
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<td>code</td>
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<td>-</td>
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<td>要比较的错误码</td>
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<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">返回值</span></h3>
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<div class="t-li1"><span class="t-li">1)</span> 若错误类别与错误值比较相等则为 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw2">true</span></span></span> 。</div>
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<div class="t-li1"><span class="t-li">2)</span> 若错误类别或错误值比较不相等则为 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw2">true</span></span></span> 。</div>
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<div class="t-li1"><span class="t-li">3)</span> 若则为 <span class="t-c"><span class="mw-geshi cpp source-cpp">lhs.<span class="me1">category</span><span class="br0">(</span><span class="br0">)</span> <span class="sy1"><</span> rhs.<span class="me1">category</span><span class="br0">(</span><span class="br0">)</span></span></span> ， <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw2">true</span></span></span> 。否则若 <span class="t-c"><span class="mw-geshi cpp source-cpp">lhs.<span class="me1">category</span><span class="br0">(</span><span class="br0">)</span> <span class="sy1">==</span> rhs.<span class="me1">category</span><span class="br0">(</span><span class="br0">)</span> <span class="sy3">&&</span> lhs.<span class="me1">value</span><span class="br0">(</span><span class="br0">)</span> <span class="sy1"><</span> rhs.<span class="me1">value</span><span class="br0">(</span><span class="br0">)</span></span></span> 则为 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw2">true</span></span></span> 。否则为 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw2">false</span></span></span> 。</div>
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<div class="t-li1"><span class="t-li">4)</span> 若 <span class="t-c"><span class="mw-geshi cpp source-cpp">lhs.<span class="me1">category</span><span class="br0">(</span><span class="br0">)</span> <span class="sy1"><=></span> rhs.<span class="me1">category</span><span class="br0">(</span><span class="br0">)</span></span></span> 不为 <span class="t-c"><span class="mw-geshi cpp source-cpp">std<span class="sy4">::</span><span class="me2">strong_ordering</span><span class="sy4">::</span><span class="me2">equal</span></span></span> 则为该值。否则为 <span class="t-c"><span class="mw-geshi cpp source-cpp">lhs.<span class="me1">value</span><span class="br0">(</span><span class="br0">)</span> <span class="sy1"><=></span> rhs.<span class="me1">value</span><span class="br0">(</span><span class="br0">)</span></span></span> 。</div>
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<div class="t-li1"><span class="t-li">5)</span> 若 <span class="t-c"><span class="mw-geshi cpp source-cpp">code.<span class="me1">category</span><span class="br0">(</span><span class="br0">)</span>.<span class="me1">equivalent</span><span class="br0">(</span>code.<span class="me1">value</span><span class="br0">(</span><span class="br0">)</span>, cond<span class="br0">)</span></span></span> 或 <span class="t-c"><span class="mw-geshi cpp source-cpp">cond.<span class="me1">category</span><span class="br0">(</span><span class="br0">)</span>.<span class="me1">equivalent</span><span class="br0">(</span>code, cond.<span class="me1">value</span><span class="br0">(</span><span class="br0">)</span><span class="br0">)</span></span></span> 则为 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw2">true</span></span></span> 。</div>
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<div class="t-li1"><span class="t-li">6)</span> 若既非 <span class="t-c"><span class="mw-geshi cpp source-cpp">code.<span class="me1">category</span><span class="br0">(</span><span class="br0">)</span>.<span class="me1">equivalent</span><span class="br0">(</span>code.<span class="me1">value</span><span class="br0">(</span><span class="br0">)</span>, cond<span class="br0">)</span></span></span> 亦非 <span class="t-c"><span class="mw-geshi cpp source-cpp">cond.<span class="me1">category</span><span class="br0">(</span><span class="br0">)</span>.<span class="me1">equivalent</span><span class="br0">(</span>code, cond.<span class="me1">value</span><span class="br0">(</span><span class="br0">)</span><span class="br0">)</span></span></span> 则为 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw2">true</span></span></span> 。</div>
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