123 lines
11 KiB
HTML
123 lines
11 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>标准库头文件 <charconv></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_header_charconv 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%">标准库头文件</span> <charconv></h1>
|
|
<div id="bodyContent">
|
|
<div id="contentSub"><span class="subpages">< <a href="cpp.html">cpp</a>‎ | <a href="cpp-header.html">header</a></span></div>
|
|
<div id="mw-content-text" lang="zh" dir="ltr" class="mw-content-ltr" xml:lang="zh">
|
|
<table class="t-dsc-begin">
|
|
<tr>
|
|
<td colspan="2">
|
|
<h3><span class="mw-headline" id=".E7.B1.BB">类</span></h3>
|
|
</td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-utility-chars_format.html"><span class="t-lines"><span>chars_format</span></span></a></div>
|
|
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx17">(C++17)</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>指定 <span class="t-lc">std::to_chars</span> 和 <span class="t-lc">std::from_chars</span> 所用的格式<br />
|
|
<span class="t-mark">(枚举)</span></td>
|
|
</tr>
|
|
<tr>
|
|
<td colspan="2">
|
|
<h3><span class="mw-headline" id=".E5.87.BD.E6.95.B0">函数</span></h3>
|
|
</td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-utility-from_chars.html"><span class="t-lines"><span>from_chars</span></span></a></div>
|
|
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx17">(C++17)</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>转换字符序列到整数或浮点值<br />
|
|
<span class="t-mark">(函数)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-utility-to_chars.html"><span class="t-lines"><span>to_chars</span></span></a></div>
|
|
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx17">(C++17)</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>转换整数或浮点值到字符序列<br />
|
|
<span class="t-mark">(函数)</span></td>
|
|
</tr>
|
|
</table>
|
|
<h3><span class="mw-headline" id=".E6.A6.82.E8.A6.81">概要</span></h3>
|
|
<div dir="ltr" class="mw-geshi" style="text-align: left;">
|
|
<div class="cpp source-cpp">
|
|
<pre class="de1"><span class="kw1">namespace</span> std <span class="br0">{</span>
|
|
<span class="co1">// 初等数值转换的浮点格式</span>
|
|
<span class="kw2">enum</span> <span class="kw1">class</span> chars_format <span class="br0">{</span>
|
|
scientific <span class="sy1">=</span> <span class="coMULTI">/* 未指明 */</span>,
|
|
fixed <span class="sy1">=</span> <span class="coMULTI">/* 未指明 */</span>,
|
|
hex <span class="sy1">=</span> <span class="coMULTI">/* 未指明 */</span>,
|
|
general <span class="sy1">=</span> fixed <span class="sy3">|</span> scientific
|
|
<span class="br0">}</span><span class="sy4">;</span>
|
|
|
|
|
|
<span class="co1">// 初等数值输出转换</span>
|
|
<span class="kw1">struct</span> to_chars_result <span class="br0">{</span>
|
|
<span class="kw4">char</span><span class="sy2">*</span> ptr<span class="sy4">;</span>
|
|
errc ec<span class="sy4">;</span>
|
|
<span class="kw1">friend</span> <span class="kw4">bool</span> operator<span class="sy1">==</span><span class="br0">(</span><span class="kw4">const</span> to_chars_result<span class="sy3">&</span>, <span class="kw4">const</span> to_chars_result<span class="sy3">&</span><span class="br0">)</span> <span class="sy1">=</span> <span class="kw1">default</span><span class="sy4">;</span>
|
|
<span class="br0">}</span><span class="sy4">;</span>
|
|
|
|
to_chars_result to_chars<span class="br0">(</span><span class="kw4">char</span><span class="sy2">*</span> first, <span class="kw4">char</span><span class="sy2">*</span> last,
|
|
<span class="coMULTI">/* 见描述 */</span> value, <span class="kw4">int</span> base <span class="sy1">=</span> <span class="nu0">10</span><span class="br0">)</span><span class="sy4">;</span>
|
|
to_chars_result to_chars<span class="br0">(</span><span class="kw4">char</span><span class="sy2">*</span> first, <span class="kw4">char</span><span class="sy2">*</span> last, <span class="kw4">bool</span> value, <span class="kw4">int</span> base <span class="sy1">=</span> <span class="nu0">10</span><span class="br0">)</span> <span class="sy1">=</span> delete<span class="sy4">;</span>
|
|
|
|
to_chars_result to_chars<span class="br0">(</span><span class="kw4">char</span><span class="sy2">*</span> first, <span class="kw4">char</span><span class="sy2">*</span> last, <span class="kw4">float</span> value<span class="br0">)</span><span class="sy4">;</span>
|
|
to_chars_result to_chars<span class="br0">(</span><span class="kw4">char</span><span class="sy2">*</span> first, <span class="kw4">char</span><span class="sy2">*</span> last, <span class="kw4">double</span> value<span class="br0">)</span><span class="sy4">;</span>
|
|
to_chars_result to_chars<span class="br0">(</span><span class="kw4">char</span><span class="sy2">*</span> first, <span class="kw4">char</span><span class="sy2">*</span> last, <span class="kw4">long</span> <span class="kw4">double</span> value<span class="br0">)</span><span class="sy4">;</span>
|
|
|
|
to_chars_result to_chars<span class="br0">(</span><span class="kw4">char</span><span class="sy2">*</span> first, <span class="kw4">char</span><span class="sy2">*</span> last, <span class="kw4">float</span> value, chars_format fmt<span class="br0">)</span><span class="sy4">;</span>
|
|
to_chars_result to_chars<span class="br0">(</span><span class="kw4">char</span><span class="sy2">*</span> first, <span class="kw4">char</span><span class="sy2">*</span> last, <span class="kw4">double</span> value, chars_format fmt<span class="br0">)</span><span class="sy4">;</span>
|
|
to_chars_result to_chars<span class="br0">(</span><span class="kw4">char</span><span class="sy2">*</span> first, <span class="kw4">char</span><span class="sy2">*</span> last, <span class="kw4">long</span> <span class="kw4">double</span> value, chars_format fmt<span class="br0">)</span><span class="sy4">;</span>
|
|
|
|
to_chars_result to_chars<span class="br0">(</span><span class="kw4">char</span><span class="sy2">*</span> first, <span class="kw4">char</span><span class="sy2">*</span> last, <span class="kw4">float</span> value,
|
|
chars_format fmt, <span class="kw4">int</span> precision<span class="br0">)</span><span class="sy4">;</span>
|
|
to_chars_result to_chars<span class="br0">(</span><span class="kw4">char</span><span class="sy2">*</span> first, <span class="kw4">char</span><span class="sy2">*</span> last, <span class="kw4">double</span> value,
|
|
chars_format fmt, <span class="kw4">int</span> precision<span class="br0">)</span><span class="sy4">;</span>
|
|
to_chars_result to_chars<span class="br0">(</span><span class="kw4">char</span><span class="sy2">*</span> first, <span class="kw4">char</span><span class="sy2">*</span> last, <span class="kw4">long</span> <span class="kw4">double</span> value,
|
|
chars_format fmt, <span class="kw4">int</span> precision<span class="br0">)</span><span class="sy4">;</span>
|
|
|
|
|
|
<span class="co1">// 初等数值输入转换</span>
|
|
<span class="kw1">struct</span> from_chars_result <span class="br0">{</span>
|
|
<span class="kw4">const</span> <span class="kw4">char</span><span class="sy2">*</span> ptr<span class="sy4">;</span>
|
|
errc ec<span class="sy4">;</span>
|
|
<span class="kw1">friend</span> <span class="kw4">bool</span> operator<span class="sy1">==</span><span class="br0">(</span><span class="kw4">const</span> from_chars_result<span class="sy3">&</span>, <span class="kw4">const</span> from_chars_result<span class="sy3">&</span><span class="br0">)</span> <span class="sy1">=</span> <span class="kw1">default</span><span class="sy4">;</span>
|
|
<span class="br0">}</span><span class="sy4">;</span>
|
|
|
|
from_chars_result from_chars<span class="br0">(</span><span class="kw4">const</span> <span class="kw4">char</span><span class="sy2">*</span> first, <span class="kw4">const</span> <span class="kw4">char</span><span class="sy2">*</span> last,
|
|
<span class="coMULTI">/* 见描述 */</span><span class="sy3">&</span> value, <span class="kw4">int</span> base <span class="sy1">=</span> <span class="nu0">10</span><span class="br0">)</span><span class="sy4">;</span>
|
|
|
|
from_chars_result from_chars<span class="br0">(</span><span class="kw4">const</span> <span class="kw4">char</span><span class="sy2">*</span> first, <span class="kw4">const</span> <span class="kw4">char</span><span class="sy2">*</span> last, <span class="kw4">float</span><span class="sy3">&</span> value,
|
|
chars_format fmt <span class="sy1">=</span> chars_format<span class="sy4">::</span><span class="me2">general</span><span class="br0">)</span><span class="sy4">;</span>
|
|
from_chars_result from_chars<span class="br0">(</span><span class="kw4">const</span> <span class="kw4">char</span><span class="sy2">*</span> first, <span class="kw4">const</span> <span class="kw4">char</span><span class="sy2">*</span> last, <span class="kw4">double</span><span class="sy3">&</span> value,
|
|
chars_format fmt <span class="sy1">=</span> chars_format<span class="sy4">::</span><span class="me2">general</span><span class="br0">)</span><span class="sy4">;</span>
|
|
from_chars_result from_chars<span class="br0">(</span><span class="kw4">const</span> <span class="kw4">char</span><span class="sy2">*</span> first, <span class="kw4">const</span> <span class="kw4">char</span><span class="sy2">*</span> last, <span class="kw4">long</span> <span class="kw4">double</span><span class="sy3">&</span> value,
|
|
chars_format fmt <span class="sy1">=</span> chars_format<span class="sy4">::</span><span class="me2">general</span><span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="br0">}</span></pre></div>
|
|
</div>
|
|
</div>
|
|
<div class="visualClear"></div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</body>
|
|
</html>
|