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<div class="section">
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="metaparse.versioning"></a><a class="link" href="versioning.html" title="Versioning">Versioning</a>
</h2></div></div></div>
<div class="toc"><dl class="toc">
<dt><span class="section"><a href="versioning.html#metaparse.versioning.template_classes">Template classes</a></span></dt>
<dt><span class="section"><a href="versioning.html#metaparse.versioning.macros">Macros</a></span></dt>
</dl></div>
<p>
This section describes how the library is prepared for supporting multiple
(not backward compatible) changes.
</p>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="metaparse.versioning.template_classes"></a><a class="link" href="versioning.html#metaparse.versioning.template_classes" title="Template classes">Template classes</a>
</h3></div></div></div>
<p>
The elements of the library are defined in the <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">metaparse</span><span class="special">::</span><span class="identifier">v1</span></code> namespace.
For example the <code class="computeroutput"><span class="identifier">one_char</span></code>
class is <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">metaparse</span><span class="special">::</span><span class="identifier">v1</span><span class="special">::</span><span class="identifier">one_char</span></code>
and is available after including the <code class="computeroutput"><span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">metaparse</span><span class="special">/</span><span class="identifier">v1</span><span class="special">/</span><span class="identifier">one_char</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code>
header file.
</p>
<p>
At the same time the library provides the <code class="computeroutput"><span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">metaparse</span><span class="special">/</span><span class="identifier">one_char</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code>
header file which includes <code class="computeroutput"><span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">metaparse</span><span class="special">/</span><span class="identifier">v1</span><span class="special">/</span><span class="identifier">one_char</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code>
and contains the following:
</p>
<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span>
<span class="special">{</span>
<span class="keyword">namespace</span> <span class="identifier">metaparse</span>
<span class="special">{</span>
<span class="keyword">using</span> <span class="identifier">v1</span><span class="special">::</span><span class="identifier">one_char</span><span class="special">;</span>
<span class="special">}</span>
<span class="special">}</span>
</pre>
<p>
This makes it possible to use <code class="computeroutput"><span class="identifier">one_char</span></code>
as <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">metaparse</span><span class="special">::</span><span class="identifier">one_char</span></code>.
</p>
<p>
Future versions of the library may provide other namespaces (eg. <code class="computeroutput"><span class="identifier">v2</span></code>). The header files in <code class="computeroutput"><span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">metaparse</span><span class="special">/...></span></code> provide the latest version of the
library. To always get version <code class="computeroutput"><span class="identifier">v1</span></code>,
one should use header files in <code class="computeroutput"><span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">metaparse</span><span class="special">/</span><span class="identifier">v1</span><span class="special">/...></span></code>.
</p>
<p>
The library does not use inline namespaces to work on compilers that do not
support them.
</p>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="metaparse.versioning.macros"></a><a class="link" href="versioning.html#metaparse.versioning.macros" title="Macros">Macros</a>
</h3></div></div></div>
<p>
Macros defined by the library are prefixed with <code class="computeroutput"><span class="identifier">BOOST_METAPARSE_V1_</span></code>.
For example <code class="computeroutput"><span class="identifier">BOOST_METAPARSE_V1_STRING</span></code>.
It is defined in the <code class="computeroutput"><span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">metaparse</span><span class="special">/</span><span class="identifier">v1</span><span class="special">/</span><span class="identifier">string</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code>
header file. The library provides the <code class="computeroutput"><span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">metaparse</span><span class="special">/</span><span class="identifier">string</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code>
header file as well, which includes the definition of this macro and provides
the following definition:
</p>
<pre class="programlisting"><span class="preprocessor">#define</span> <span class="identifier">BOOST_METAPARSE_STRING</span> <span class="identifier">BOOST_METAPARSE_V1_STRING</span>
</pre>
<p>
This makes it possible to use the macro as <code class="computeroutput"><span class="identifier">BOOST_METAPARSE_STRING</span></code>.
Future versions of the library may define other versions of this macro (eg.
<code class="computeroutput"><span class="identifier">BOOST_METAPARSE_V2_STRING</span></code>).
<code class="computeroutput"><span class="identifier">BOOST_METAPARSE_STRING</span></code> will
refer to the latest version.
</p>
<p>
This versioning does not affect macros that may be overridden by the code
using the library. (eg. <code class="computeroutput"><span class="identifier">BOOST_METAPARSE_LIMIT_STRING_SIZE</span></code>)
</p>
</div>
</div>
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<td align="right"><div class="copyright-footer">Copyright © 2015 Abel Sinkovics<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
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>)
</p>
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