generic-library/boost
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

[DEV] add v1.76.0

Browse Source
This commit is contained in:
Edouard DUPIN
2021-10-05 21:37:46 +02:00
parent a97e9ae7d4
commit d0115b733d
45133 changed files with 4744437 additions and 1026325 deletions
Download Patch File Download Diff File Expand all files Collapse all files

227
doc/html/boost_dll/getting_started.html Normal file
View File

@@ -0,0 +1,227 @@
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Getting started</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="The Boost C++ Libraries BoostBook Documentation Subset">
<link rel="up" href="../boost_dll.html" title="Chapter 14. Boost.DLL">
<link rel="prev" href="../boost_dll.html" title="Chapter 14. Boost.DLL">
<link rel="next" href="tutorial.html" title="Tutorial">
</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="../boost_dll.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../boost_dll.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="tutorial.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_dll.getting_started"></a><a class="link" href="getting_started.html" title="Getting started">Getting started</a>
</h2></div></div></div>
<p>
Boost.DLL is a header only library. To start with the library you only need
to include <code class="computeroutput"><span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">dll</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span></code> header.
After that you are free to import and export functions and variables. Importing
code requires linking with <code class="computeroutput"><span class="identifier">boost_filesystem</span></code>
and <code class="computeroutput"><span class="identifier">boost_system</span></code> libraries.
</p>
<p>
If you want to load a library, just construct <code class="computeroutput"><a class="link" href="../boost/dll/shared_library.html" title="Class shared_library">boost::dll::shared_library</a></code>
class with a path to the library as a parameter:
</p>
<pre class="programlisting"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">dll</span><span class="special">::</span><span class="identifier">shared_library</span> <span class="identifier">lib</span><span class="special">(</span><span class="string">"/test/boost/application/libtest_library.so"</span><span class="special">);</span>
</pre>
<p>
Now you can easily import symbols from that library using the <code class="computeroutput"><span class="identifier">get</span></code> and <code class="computeroutput"><span class="identifier">get_alias</span></code>
member functions:
</p>
<pre class="programlisting"><span class="keyword">int</span> <span class="identifier">plugin_constant</span> <span class="special">=</span> <span class="identifier">lib</span><span class="special">.</span><span class="identifier">get</span><span class="special">&lt;</span><span class="keyword">const</span> <span class="keyword">int</span><span class="special">&gt;(</span><span class="string">"integer_variable"</span><span class="special">);</span>
<span class="identifier">boost</span><span class="special">::</span><span class="identifier">function</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">()&gt;</span> <span class="identifier">f</span> <span class="special">=</span> <span class="identifier">lib</span><span class="special">.</span><span class="identifier">get</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">()&gt;(</span><span class="string">"function_returning_int"</span><span class="special">);</span>
<span class="keyword">int</span><span class="special">&amp;</span> <span class="identifier">i</span> <span class="special">=</span> <span class="identifier">lib</span><span class="special">.</span><span class="identifier">get_alias</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">&gt;(</span><span class="string">"alias_to_int_variable"</span><span class="special">);</span>
</pre>
<p>
In case of <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">dll</span><span class="special">::</span><span class="identifier">shared_library</span></code>
it is safe to use imported symbols only until <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">dll</span><span class="special">::</span><span class="identifier">shared_library</span></code> instance is not destroyed.
</p>
<p>
Query libraries using <code class="computeroutput"><a class="link" href="../boost/dll/library_info.html" title="Class library_info">boost::dll::library_info</a></code>
and get symbol infos using <code class="computeroutput"><a class="link" href="../boost/dll/symbol_location.html" title="Function symbol_location">boost::dll::symbol_location</a></code>,
<code class="computeroutput"><a class="link" href="../boost/dll/this_line_location.html" title="Function this_line_location">boost::dll::this_line_location</a></code>
and <code class="computeroutput"><a class="link" href="../boost/dll/program_location.html" title="Function program_location">boost::dll::program_location</a></code>.
</p>
<p>
For importing a single function or variable you may use a following one liners:
</p>
<p>
</p>
<pre class="programlisting"><span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">;</span>
<span class="comment">// `extern "C"` - specifies C linkage: forces the compiler to export function/variable by a pretty (unmangled) C name.</span>
<span class="preprocessor">#define</span> <span class="identifier">API</span> <span class="keyword">extern</span> <span class="string">"C"</span> <span class="identifier">BOOST_SYMBOL_EXPORT</span>
</pre>
<p>
</p>
<div class="informaltable">
<a name="boost_dll.getting_started.starting"></a><table class="table">
<colgroup>
<col>
<col>
<col>
</colgroup>
<thead><tr>
<th>
<p>
Import (code that uses DLL/DSL):
</p>
</th>
<th>
<p>
Export (DLL/DSL sources):
</p>
</th>
<th>
<p>
Functions description:
</p>
</th>
</tr></thead>
<tbody>
<tr>
<td>
<p>
</p>
<pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="comment">// Importing function.</span>
<span class="keyword">auto</span> <span class="identifier">cpp11_func</span> <span class="special">=</span> <span class="identifier">dll</span><span class="special">::</span><span class="identifier">import_symbol</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&amp;&amp;)&gt;(</span>
<span class="identifier">path_to_shared_library</span><span class="special">,</span> <span class="string">"i_am_a_cpp11_function"</span>
<span class="special">);</span>
</pre>
<p>
</p>
</td>
<td>
<p>
</p>
<pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="keyword">namespace</span> <span class="identifier">some_namespace</span> <span class="special">{</span>
<span class="identifier">API</span> <span class="keyword">int</span> <span class="identifier">i_am_a_cpp11_function</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&amp;&amp;</span> <span class="identifier">param</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span>
<span class="comment">// ^-------------------- function name to use in dll::import_symbol&lt;&gt;</span>
<span class="special">}</span>
</pre>
<p>
</p>
</td>
<td>
<p>
<code class="computeroutput">import&lt;T&gt;(...)</code>
</p>
</td>
</tr>
<tr>
<td>
<p>
</p>
<pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="comment">// Importing variable.</span>
<span class="identifier">shared_ptr</span><span class="special">&lt;</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&gt;</span> <span class="identifier">cpp_var</span> <span class="special">=</span> <span class="identifier">dll</span><span class="special">::</span><span class="identifier">import_symbol</span><span class="special">&lt;</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&gt;(</span>
<span class="identifier">path_to_shared_library</span><span class="special">,</span> <span class="string">"cpp_variable_name"</span>
<span class="special">);</span>
</pre>
<p>
</p>
</td>
<td>
<p>
</p>
<pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="keyword">namespace</span> <span class="identifier">your_project_namespace</span> <span class="special">{</span>
<span class="identifier">API</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">cpp_variable_name</span><span class="special">;</span>
<span class="special">}</span>
</pre>
<p>
</p>
</td>
<td>
<p>
<code class="computeroutput">import&lt;T&gt;(...)</code>
</p>
</td>
</tr>
<tr>
<td>
<p>
</p>
<pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="comment">// Importing function by alias name</span>
<span class="keyword">auto</span> <span class="identifier">cpp_func</span> <span class="special">=</span> <span class="identifier">dll</span><span class="special">::</span><span class="identifier">import_alias</span><span class="special">&lt;</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&amp;)&gt;(</span>
<span class="identifier">path_to_shared_library</span><span class="special">,</span> <span class="string">"pretty_name"</span>
<span class="special">);</span>
</pre>
<p>
</p>
</td>
<td>
<p>
</p>
<pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="keyword">namespace</span> <span class="identifier">some_namespace</span> <span class="special">{</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">i_am_function_with_ugly_name</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&amp;</span> <span class="identifier">param</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span>
<span class="special">}</span>
<span class="comment">// When you have no control over function sources or wish to specify another name.</span>
<span class="identifier">BOOST_DLL_ALIAS</span><span class="special">(</span><span class="identifier">some_namespace</span><span class="special">::</span><span class="identifier">i_am_function_with_ugly_name</span><span class="special">,</span> <span class="identifier">pretty_name</span><span class="special">)</span>
</pre>
<p>
</p>
</td>
<td>
<p>
<code class="computeroutput"><a class="link" href="../boost/dll/import_alias.html" title="Function import_alias">import_alias&lt;T&gt;(...)</a></code>
</p>
<p>
<code class="computeroutput"><a class="link" href="../BOOST_DLL_ALIAS.html" title="Macro BOOST_DLL_ALIAS">BOOST_DLL_ALIAS</a></code>
</p>
</td>
</tr>
</tbody>
</table>
</div>
<p>
It is safe to use imported variable or function because the variables returned
from <code class="computeroutput">import&lt;T&gt;(...)</code>
and <code class="computeroutput"><a class="link" href="../boost/dll/import_alias.html" title="Function import_alias">import_alias&lt;T&gt;(...)</a></code>
functions internally hold a reference to the shared library.
</p>
<p>
<code class="computeroutput">BOOST_SYMBOL_EXPORT</code> is just
a macro from Boost.Config that expands into the <code class="computeroutput"><span class="identifier">__declspec</span><span class="special">(</span><span class="identifier">dllexport</span><span class="special">)</span></code> or <code class="computeroutput"><span class="identifier">__attribute__</span><span class="special">((</span><span class="identifier">visibility</span><span class="special">(</span><span class="string">"default"</span><span class="special">)))</span></code>. You are free to use your own macro for
exports.
</p>
<div class="note"><table border="0" summary="Note">
<tr>
<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../doc/src/images/note.png"></td>
<th align="left">Note</th>
</tr>
<tr><td align="left" valign="top"><p>
On Linux/POSIX/MacOS link with library "dl". "-fvisibility=hidden"
flag is also recommended.
</p></td></tr>
</table></div>
</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 © 2014 Renato Tegon Forti, Antony Polukhin<br>Copyright © 2015 Antony Polukhin<br>Copyright © 2016 Antony Polukhin, Klemens Morgenstern<br>Copyright © 2017-2021 Antony Polukhin<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
</p>
</div></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="../boost_dll.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../boost_dll.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="tutorial.html"><img src="../../../doc/src/images/next.png" alt="Next"></a>
</div>
</body>
</html>