161 lines
12 KiB
HTML
161 lines
12 KiB
HTML
<!DOCTYPE html>
|
|
<html lang="zh" dir="ltr" class="client-nojs" xmlns="http://www.w3.org/1999/xhtml" xml:lang="zh">
|
|
<head><meta http-equiv="x-ua-compatible" content="ie=edge">
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
|
|
<title>std::binary_function</title>
|
|
<link rel="stylesheet" href="ext.css" />
|
|
<link rel="stylesheet" href="site_modules.css" />
|
|
</head>
|
|
<body class="mediawiki ltr sitedir-ltr ns-0 ns-subject page-cpp_utility_functional_binary_function skin-cppreference2 action-view cpp-navbar">
|
|
<div id="cpp-content-base">
|
|
<div id="content"><a id="top"></a>
|
|
<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::</span>binary_function</h1>
|
|
<div id="bodyContent">
|
|
<div id="contentSub"><span class="subpages">< <a href="cpp.html">cpp</a>‎ | <a href="cpp-utility.html">utility</a>‎ | <a href="cpp-utility-functional.html">functional</a></span></div>
|
|
<div id="mw-content-text" lang="zh" dir="ltr" class="mw-content-ltr" xml:lang="zh">
|
|
<table class="t-dcl-begin">
|
|
<tbody>
|
|
<tr class="t-dsc-header">
|
|
<td>
|
|
<div>定义于头文件 <code><a href="cpp-header-functional.html"><functional></a></code></div>
|
|
</td>
|
|
<td></td>
|
|
<td></td>
|
|
</tr>
|
|
<tr class="t-dcl t-until-cxx17">
|
|
<td>
|
|
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1"><</span><br /></span>
|
|
<p> <span class="kw1">class</span> Arg1,<br />
|
|
<span class="kw1">class</span> Arg2,<br />
|
|
<span class="kw1">class</span> Result<br /></p>
|
|
<span class="sy1">></span> <span class="kw1">struct</span> binary_function<span class="sy4">;</span></div>
|
|
</td>
|
|
<td class="t-dcl-nopad"></td>
|
|
<td><span class="t-mark">(C++11 中弃用)</span><br />
|
|
<span class="t-mark-rev t-until-cxx17">(C++17 中移除)</span></td>
|
|
</tr>
|
|
<tr class="t-dcl-sep">
|
|
<td></td>
|
|
<td></td>
|
|
<td></td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
<p><code>binary_function</code> 是用于创建拥有二个参数的函数对象的基类。</p>
|
|
<p><code>binary_function</code> 不定义 <span class="t-c"><span class="mw-geshi cpp source-cpp">operator<span class="br0">(</span><span class="br0">)</span></span></span> ；它期待导出类将定义此运算符。 <code>binary_function</code> 只提供三个类型—— <code>first_argument_type</code> 、 <code>second_argument_type</code> 和 <code>result_type</code> ——为模板形参所定义。</p>
|
|
<p>一些标准库函数适配器，如 <span class="t-lc"><a href="cpp-utility-functional-not2.html">std::not2</a></span> 要求其适配的函数对象必须定义这些类型； <span class="t-lc"><a href="cpp-utility-functional-not2.html">std::not2</a></span> 要求要适配的函数对象必须拥有二个名为 <code>first_argument_type</code> 和 <code>second_argument_type</code> 的类型。从 <code>binary_function</code> 导出接受二个参数的函数对象是令它们与那些适配器兼容的简便方式。</p>
|
|
<p><code>binary_function</code> 于 C++11 弃用并于 C++17 移除。</p>
|
|
<h3><span class="mw-headline" id=".E6.88.90.E5.91.98.E7.B1.BB.E5.9E.8B">成员类型</span></h3>
|
|
<table class="t-dsc-begin">
|
|
<tr class="t-dsc-hitem">
|
|
<td>类型</td>
|
|
<td>定义</td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td><code>first_argument_type</code></td>
|
|
<td><code>Arg1</code></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td><code>second_argument_type</code></td>
|
|
<td><code>Arg2</code></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td><code>result_type</code></td>
|
|
<td><code>Result</code></td>
|
|
</tr>
|
|
</table>
|
|
<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">示例</span></h3>
|
|
<div class="t-example">
|
|
<div class="t-example-live-link"></div>
|
|
<div dir="ltr" class="mw-geshi" style="text-align: left;">
|
|
<div class="cpp source-cpp">
|
|
<pre class="de1"><span class="co2">#include <algorithm></span>
|
|
<span class="co2">#include <functional></span>
|
|
<span class="co2">#include <iostream></span>
|
|
<span class="co2">#include <vector></span>
|
|
|
|
<span class="kw1">struct</span> same <span class="sy4">:</span> std<span class="sy4">::</span><span class="me2">binary_function</span><span class="sy1"><</span><span class="kw4">int</span>, <span class="kw4">int</span>, <span class="kw4">bool</span><span class="sy1">></span>
|
|
<span class="br0">{</span>
|
|
<span class="kw4">bool</span> operator<span class="br0">(</span><span class="br0">)</span><span class="br0">(</span><span class="kw4">int</span> a, <span class="kw4">int</span> b<span class="br0">)</span> <span class="kw4">const</span> <span class="br0">{</span> <span class="kw1">return</span> a <span class="sy1">==</span> b<span class="sy4">;</span> <span class="br0">}</span>
|
|
<span class="br0">}</span><span class="sy4">;</span>
|
|
|
|
<span class="kw4">int</span> main<span class="br0">(</span><span class="br0">)</span>
|
|
<span class="br0">{</span>
|
|
<a href="cpp-container-vector.html"><span class="kw1268">std::<span class="me2">vector</span></span></a><span class="sy1"><</span><span class="kw4">int</span><span class="sy1">></span> v1<span class="br0">{</span> <span class="nu0">0</span>, <span class="nu0">1</span>, <span class="nu0">2</span>, <span class="nu0">3</span>, <span class="nu0">4</span>, <span class="nu0">5</span>, <span class="nu0">6</span>, <span class="nu0">7</span>, <span class="nu0">8</span>, <span class="nu0">9</span>, <span class="nu0">10</span><span class="br0">}</span><span class="sy4">;</span>
|
|
<a href="cpp-container-vector.html"><span class="kw1268">std::<span class="me2">vector</span></span></a><span class="sy1"><</span><span class="kw4">int</span><span class="sy1">></span> v2<span class="br0">{</span><span class="nu0">10</span>, <span class="nu0">9</span>, <span class="nu0">8</span>, <span class="nu0">7</span>, <span class="nu0">6</span>, <span class="nu0">5</span>, <span class="nu0">4</span>, <span class="nu0">3</span>, <span class="nu0">2</span>, <span class="nu0">1</span>, <span class="nu0">0</span> <span class="br0">}</span><span class="sy4">;</span>
|
|
<a href="cpp-container-vector.html"><span class="kw1268">std::<span class="me2">vector</span></span></a><span class="sy1"><</span><span class="kw4">bool</span><span class="sy1">></span> v3<span class="br0">(</span>v1.<span class="me1">size</span><span class="br0">(</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
|
|
|
|
<a href="cpp-algorithm-transform.html"><span class="kw1588">std::<span class="me2">transform</span></span></a><span class="br0">(</span>v1.<span class="me1">begin</span><span class="br0">(</span><span class="br0">)</span>, v1.<span class="me1">end</span><span class="br0">(</span><span class="br0">)</span>, v2.<span class="me1">begin</span><span class="br0">(</span><span class="br0">)</span>, v3.<span class="me1">begin</span><span class="br0">(</span><span class="br0">)</span>, <a href="cpp-utility-functional-not2.html"><span class="kw1051">std::<span class="me2">not2</span></span></a><span class="br0">(</span>same<span class="br0">(</span><span class="br0">)</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
|
|
|
|
<a href="cpp-io-cout.html"><span class="kw1757">std::<span class="me2">cout</span></span></a> <span class="sy1"><<</span> <a href="cpp-io-manip-boolalpha.html"><span class="kw1763">std::<span class="me2">boolalpha</span></span></a><span class="sy4">;</span>
|
|
<span class="kw1">for</span> <span class="br0">(</span><a href="cpp-types-size_t.html"><span class="kw100">std::<span class="me2">size_t</span></span></a> i <span class="sy1">=</span> <span class="nu0">0</span><span class="sy4">;</span> i <span class="sy1"><</span> v1.<span class="me1">size</span><span class="br0">(</span><span class="br0">)</span><span class="sy4">;</span> <span class="sy2">++</span>i<span class="br0">)</span>
|
|
<a href="cpp-io-cout.html"><span class="kw1757">std::<span class="me2">cout</span></span></a> <span class="sy1"><<</span> v1<span class="br0">[</span>i<span class="br0">]</span> <span class="sy1"><<</span> <span class="st0">' '</span> <span class="sy1"><<</span> v2<span class="br0">[</span>i<span class="br0">]</span> <span class="sy1"><<</span> <span class="st0">' '</span> <span class="sy1"><<</span> v3<span class="br0">[</span>i<span class="br0">]</span> <span class="sy1"><<</span> <span class="st0">'<span class="es1">\n</span>'</span><span class="sy4">;</span>
|
|
<span class="br0">}</span></pre></div>
|
|
</div>
|
|
<p>输出：</p>
|
|
<div dir="ltr" class="mw-geshi" style="text-align: left;">
|
|
<div class="text source-text">
|
|
<pre class="de1">0 10 true
|
|
1 9 true
|
|
2 8 true
|
|
3 7 true
|
|
4 6 true
|
|
5 5 false
|
|
6 4 true
|
|
7 3 true
|
|
8 2 true
|
|
9 1 true
|
|
10 0 true</pre></div>
|
|
</div>
|
|
</div>
|
|
<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">参阅</span></h3>
|
|
<table class="t-dsc-begin">
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-utility-functional-function.html"><span class="t-lines"><span>function</span></span></a></div>
|
|
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>包装具有指定函数调用签名的任意可复制构造类型的可调用对象<br />
|
|
<span class="t-mark">(类模板)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-utility-functional-ptr_fun.html"><span class="t-lines"><span>ptr_fun</span></span></a></div>
|
|
<div><span class="t-lines"><span><span class="t-mark-rev t-deprecated-cxx11">(C++11 中弃用)</span><span class="t-mark-rev t-until-cxx17">(C++17 中移除)</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>从函数指针创建与适配器兼容的函数对象包装器<br />
|
|
<span class="t-mark">(函数模板)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-utility-functional-pointer_to_binary_function.html"><span class="t-lines"><span>pointer_to_binary_function</span></span></a></div>
|
|
<div><span class="t-lines"><span><span class="t-mark-rev t-deprecated-cxx11">(C++11 中弃用)</span></span><span><span class="t-mark-rev t-until-cxx17">(C++17 中移除)</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>适配器兼容的包装，用于包装二元函数的指针<br />
|
|
<span class="t-mark">(类模板)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-utility-functional-unary_function.html"><span class="t-lines"><span>unary_function</span></span></a></div>
|
|
<div><span class="t-lines"><span><span class="t-mark-rev t-deprecated-cxx11">(C++11 中弃用)</span></span><span><span class="t-mark-rev t-until-cxx17">(C++17 中移除)</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>与适配器兼容的一元函数基类<br />
|
|
<span class="t-mark">(类模板)</span></td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<div class="visualClear"></div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</body>
|
|
</html>
|