1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Boost.StaticString</title> 5<link rel="stylesheet" href="../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="index.html" title="Boost.StaticString"> 8<link rel="next" href="static_string/ref.html" title="Reference"> 9</head> 10<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 11<table cellpadding="2" width="100%"><tr> 12<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../boost.png"></td> 13<td align="center"><a href="../../../../index.html">Home</a></td> 14<td align="center"><a href="../../../../libs/libraries.htm">Libraries</a></td> 15<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 16<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 17<td align="center"><a href="../../../../more/index.htm">More</a></td> 18</tr></table> 19<hr> 20<div class="spirit-nav"><a accesskey="n" href="static_string/ref.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a></div> 21<div class="chapter"> 22<div class="titlepage"><div> 23<div><h2 class="title"> 24<a name="static_string"></a>Boost.StaticString</h2></div> 25<div><div class="author"><h3 class="author"> 26<span class="firstname">Krystian</span> <span class="surname">Stasiowski</span> 27</h3></div></div> 28<div><div class="author"><h3 class="author"> 29<span class="firstname">Vinnie</span> <span class="surname">Falco</span> 30</h3></div></div> 31<div><p class="copyright">Copyright © 2019, 2020 Krystian Stasiowski</p></div> 32<div><p class="copyright">Copyright © 2016-2019 Vinnie 33 Falco</p></div> 34<div><div class="legalnotice"> 35<a name="static_string.legal"></a><p> 36 Distributed under the Boost Software License, Version 1.0. (See accompanying 37 file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) 38 </p> 39</div></div> 40</div></div> 41<h3> 42<a name="static_string.h0"></a> 43 <span class="phrase"><a name="static_string.introduction"></a></span><a class="link" href="index.html#static_string.introduction">Introduction</a> 44 </h3> 45<p> 46 This library provides a dynamically resizable string of characters with compile-time 47 fixed capacity and contiguous embedded storage in which the characters are placed 48 within the string object itself. Its API closely resembles that of <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span></code>. 49 </p> 50<h3> 51<a name="static_string.h1"></a> 52 <span class="phrase"><a name="static_string.motivation"></a></span><a class="link" href="index.html#static_string.motivation">Motivation</a> 53 </h3> 54<p> 55 A fixed capacity string is useful when: 56 </p> 57<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 58<li class="listitem"> 59 Memory allocation is not possible, e.g., embedded environments without a 60 free store, where only a stack and the static memory segment are available. 61 </li> 62<li class="listitem"> 63 Memory allocation imposes an unacceptable performance penalty. e.g., with 64 respect to latency. 65 </li> 66<li class="listitem"> 67 Allocation of objects with complex lifetimes in the static-memory segment 68 is required. 69 </li> 70<li class="listitem"> 71 A dynamically-resizable string is required within <code class="computeroutput"><span class="keyword">constexpr</span></code> 72 functions. 73 </li> 74<li class="listitem"> 75 The storage location of the static_vector elements is required to be within 76 the string object itself (e.g. to support <code class="computeroutput"><span class="identifier">memcpy</span></code> 77 for serialization purposes). 78 </li> 79</ul></div> 80<h3> 81<a name="static_string.h2"></a> 82 <span class="phrase"><a name="static_string.requirements"></a></span><a class="link" href="index.html#static_string.requirements">Requirements</a> 83 </h3> 84<p> 85 The library is usable in two different modes: standalone and Boost dependent. 86 This library defaults to Boost dependent mode; standalone mode is opt-in through 87 the use of a configuration macro. 88 </p> 89<p> 90 When in Boost dependent mode, the library requires the use of at least C++11, 91 in addition to Boost.Core, Boost.Utility, and Boost.ContainerHash. In standalone 92 mode, C++17 is required but no libraries except for the standard library are 93 needed. 94 </p> 95<h3> 96<a name="static_string.h3"></a> 97 <span class="phrase"><a name="static_string.design"></a></span><a class="link" href="index.html#static_string.design">Design</a> 98 </h3> 99<p> 100 The over-arching design goal is to resemble the interface and behavior of <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span></code> 101 as much as possible. When any operation would exceed the maximum allowed size 102 of the string, <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">length_error</span></code> is thrown if exceptions are enabled. 103 All algorithms which throw exceptions provide the strong exception safety guarantee. 104 This is intended to be a drop in replacement for <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span></code>. 105 </p> 106<p> 107 The API of <code class="computeroutput"><span class="identifier">static_string</span></code> only 108 diverges from <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span></code> in few places, one of which is the addition 109 of the <code class="computeroutput"><span class="identifier">subview</span></code> function, for 110 which this implementation returns a string view instead of <code class="computeroutput"><span class="identifier">static_string</span></code>, 111 and certain functions that will never throw are marked as <code class="computeroutput"><span class="keyword">noexcept</span></code>, 112 which diverges from those of <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span></code>. The 113 available overloads for <code class="computeroutput"><span class="identifier">static_string</span></code> 114 are identical to those of <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span></code>. 115 </p> 116<h3> 117<a name="static_string.h4"></a> 118 <span class="phrase"><a name="static_string.iterators"></a></span><a class="link" href="index.html#static_string.iterators">Iterators</a> 119 </h3> 120<p> 121 The iterator invalidation rules differ from those of <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span></code>: 122 </p> 123<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 124<li class="listitem"> 125 Moving a <code class="computeroutput"><span class="identifier">static_string</span></code> invalidates 126 all iterators 127 </li> 128<li class="listitem"> 129 Swapping two <code class="computeroutput"><span class="identifier">static_string</span></code>s 130 invalidates all iterators 131 </li> 132</ul></div> 133<h3> 134<a name="static_string.h5"></a> 135 <span class="phrase"><a name="static_string.optimizations"></a></span><a class="link" href="index.html#static_string.optimizations">Optimizations</a> 136 </h3> 137<p> 138 Depending on the character type and size used for a specialization of <code class="computeroutput"><span class="identifier">static_string</span></code>, certain optimizations are used 139 to reduce the size of the class type. Given the name of a specialization of the 140 form <code class="computeroutput"><span class="identifier">basic_static_string</span><span class="special"><</span><span class="identifier">N</span><span class="special">,</span> <span class="identifier">CharT</span><span class="special">,</span> <span class="identifier">Traits</span><span class="special">></span></code>: 141 </p> 142<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 143<li class="listitem"> 144 If <code class="computeroutput"><span class="identifier">N</span></code> is 0, then the class 145 has no non-static data members. Given two objects <code class="computeroutput"><span class="identifier">a</span></code> 146 and <code class="computeroutput"><span class="identifier">b</span></code> of type <code class="computeroutput"><span class="identifier">basic_static_string</span><span class="special"><</span><span class="number">0</span><span class="special">,</span> <span class="identifier">T</span><span class="special">,</span> <span class="identifier">Traits</span><span class="special">></span></code> and <code class="computeroutput"><span class="identifier">static_string</span><span class="special"><</span><span class="number">0</span><span class="special">,</span> 147 <span class="identifier">U</span><span class="special">,</span> <span class="identifier">Traits</span><span class="special">></span></code> 148 respectively, the pointer value returned by <code class="computeroutput"><span class="identifier">data</span><span class="special">()</span></code> will be the same if <code class="computeroutput"><span class="identifier">T</span></code> 149 and <code class="computeroutput"><span class="identifier">U</span></code> are the same. 150 </li> 151<li class="listitem"> 152 Otherwise, the type of the member used to store the size of the <code class="computeroutput"><span class="identifier">static_string</span></code> will be the smallest standard 153 unsigned integer type that can represent the value <code class="computeroutput"><span class="identifier">N</span></code>. 154 </li> 155</ul></div> 156<h3> 157<a name="static_string.h6"></a> 158 <span class="phrase"><a name="static_string.configuration"></a></span><a class="link" href="index.html#static_string.configuration">Configuration</a> 159 </h3> 160<p> 161 Certain features can be enabled and disabled though defining configuration macros. 162 The macros and the associated feature they control are: 163 </p> 164<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"> 165 <code class="computeroutput"><span class="identifier">BOOST_STATIC_STRING_STANDALONE</span></code>: 166 When defined, the library is put into standalone mode. 167 </li></ul></div> 168<h3> 169<a name="static_string.h7"></a> 170 <span class="phrase"><a name="static_string.acknowledgments"></a></span><a class="link" href="index.html#static_string.acknowledgments">Acknowledgments</a> 171 </h3> 172<p> 173 Thanks to <a href="https://github.com/K-ballo" target="_top">Agustín Bergé</a>, <a href="https://github.com/pdimov" target="_top">Peter Dimov</a>, <a href="https://github.com/glenfe" target="_top">Glen 174 Fernandes</a>, and <a href="https://github.com/LeonineKing1199" target="_top">Christian 175 Mazakas</a> for their constant feedback and guidance during the development 176 of this library. 177 </p> 178<p> 179 The development of this library is sponsored by <a href="https://cppalliance.org" target="_top">The 180 C++ Alliance</a>. 181 </p> 182<h3> 183<a name="static_string.h8"></a> 184 <span class="phrase"><a name="static_string.reference"></a></span><a class="link" href="index.html#static_string.reference">Reference</a> 185 </h3> 186<p> 187 Defined in namespace <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">static_strings</span></code>: 188 </p> 189<p> 190 <a class="link" href="static_string/ref/boost__static_strings__basic_static_string.html" title="basic_static_string"><code class="computeroutput"><span class="identifier">basic_static_string</span></code></a> 191 </p> 192</div> 193<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 194<td align="left"><p><small>Last revised: August 11, 2020 at 14:59:20 GMT</small></p></td> 195<td align="right"><div class="copyright-footer"></div></td> 196</tr></table> 197<hr> 198<div class="spirit-nav"><a accesskey="n" href="static_string/ref.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a></div> 199</body> 200</html> 201
