generic-library/boost
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity
boost/libs/convert/doc/html/boost_convert/other_conversions.html
Edouard DUPIN d0115b733d [DEV] add v1.76.0
2021-10-05 21:37:46 +02:00

73 lines
6.7 KiB
HTML
Raw Permalink Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Beyond Basic Conversions</title>
<link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css">
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
<link rel="home" href="../index.html" title="Chapter 1. Boost.Convert 2.0">
<link rel="up" href="../index.html" title="Chapter 1. Boost.Convert 2.0">
<link rel="prev" href="performance/the_bigger_picture.html" title="The Bigger Picture">
<link rel="next" href="converters_detail.html" title="Converters in Detail">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table cellpadding="2" width="100%"><tr>
<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../boost.png"></td>
<td align="center"><a href="../../../../../index.html">Home</a></td>
<td align="center"><a href="../../../../../libs/libraries.htm">Libraries</a></td>
<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
<td align="center"><a href="../../../../../more/index.htm">More</a></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="performance/the_bigger_picture.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="converters_detail.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a>
</div>
<div class="section">
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="boost_convert.other_conversions"></a><a class="link" href="other_conversions.html" title="Beyond Basic Conversions">Beyond Basic Conversions</a>
</h2></div></div></div>
<p>
An interesting (and yet to be fully explored) property of the described design
is that <span class="emphasis"><em>Boost.Convert</em></span> is not limited to string-to-type
and type-to-string conversions. The <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">convert</span><span class="special">()</span></code> interface is type-agnostic and the plugged-in
converter ultimately dictates what type transformations are available. Consequently,
a wide range of conversion/transformation-related tasks can be addressed and
<span class="emphasis"><em>deployed uniformly</em></span> by plugging-in special-purpose converters.
</p>
<p>
As an experiment, the code below (taken from <span class="emphasis"><em>test/encryption.cpp</em></span>)
does not do type conversion. Instead, it applies a string transformation:
</p>
<pre class="programlisting"><span class="identifier">string</span> <span class="identifier">encrypted</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">convert</span><span class="special">&lt;</span><span class="identifier">string</span><span class="special">&gt;(</span><span class="string">"ABC"</span><span class="special">,</span> <span class="identifier">my_cypher</span><span class="special">).</span><span class="identifier">value</span><span class="special">();</span>
<span class="identifier">string</span> <span class="identifier">decrypted</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">convert</span><span class="special">&lt;</span><span class="identifier">string</span><span class="special">&gt;(</span><span class="identifier">encrypted</span><span class="special">,</span> <span class="identifier">my_cypher</span><span class="special">).</span><span class="identifier">value</span><span class="special">();</span>
<span class="identifier">BOOST_ASSERT</span><span class="special">(</span><span class="identifier">encrypted</span> <span class="special">==</span> <span class="string">"123"</span><span class="special">);</span>
<span class="identifier">BOOST_ASSERT</span><span class="special">(</span><span class="identifier">decrypted</span> <span class="special">==</span> <span class="string">"ABC"</span><span class="special">);</span>
</pre>
<p>
The original "ABC" string is "encrypted" as "123"
first and then "123" is "decrypted" back to its original
"ABC" form.
</p>
<p>
Similarly, I personally do not immediately see as objectionable string-transformations
like:
</p>
<pre class="programlisting"><span class="identifier">std</span><span class="special">::</span><span class="identifier">u8string</span> <span class="identifier">utf8</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">convert</span><span class="special">&lt;</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">u8string</span><span class="special">&gt;(</span><span class="identifier">utf32_str</span><span class="special">,</span> <span class="identifier">cnv</span><span class="special">);</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">u8string</span> <span class="identifier">utf8</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">convert</span><span class="special">&lt;</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">u8string</span><span class="special">&gt;(</span><span class="identifier">mbcs_str</span><span class="special">,</span> <span class="identifier">cnv</span><span class="special">);</span>
</pre>
</div>
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
<td align="left"></td>
<td align="right"><div class="copyright-footer">Copyright © 2009-2020 Vladimir Batov<p>
Distributed under the Boost Software License, Version 1.0. See copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>.
</p>
</div></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="performance/the_bigger_picture.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="converters_detail.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a>
</div>
</body>
</html>
Reference in New Issue View Git Blame Copy Permalink