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diff --git a/doc/html/move/composition_inheritance.html b/doc/html/move/composition_inheritance.html new file mode 100755 index 0000000000..0018d39fbc --- /dev/null +++ b/doc/html/move/composition_inheritance.html @@ -0,0 +1,154 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Composition or inheritance</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../move.html" title="Chapter 16. Boost.Move"> +<link rel="prev" href="implementing_movable_classes.html" title="Implementing copyable and movable classes"> +<link rel="next" href="movable_only_classes.html" title="Movable but Non-Copyable Types"> +</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="implementing_movable_classes.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="movable_only_classes.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="move.composition_inheritance"></a><a class="link" href="composition_inheritance.html" title="Composition or inheritance">Composition or inheritance</a> +</h2></div></div></div> +<p> + For classes made up of other classes (via either composition or inheritance), + the move constructor and move assignment can be easily coded using the <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">move</span></code> + function: + </p> +<p> +</p> +<pre class="programlisting"><span class="keyword">class</span> <span class="identifier">Base</span> +<span class="special">{</span> + <span class="identifier">BOOST_COPYABLE_AND_MOVABLE</span><span class="special">(</span><span class="identifier">Base</span><span class="special">)</span> + + <span class="keyword">public</span><span class="special">:</span> + <span class="identifier">Base</span><span class="special">(){}</span> + + <span class="identifier">Base</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">Base</span> <span class="special">&</span><span class="identifier">x</span><span class="special">)</span> <span class="special">{/**/}</span> <span class="comment">// Copy ctor</span> + + <span class="identifier">Base</span><span class="special">(</span><span class="identifier">BOOST_RV_REF</span><span class="special">(</span><span class="identifier">Base</span><span class="special">)</span> <span class="identifier">x</span><span class="special">)</span> <span class="special">{/**/}</span> <span class="comment">// Move ctor</span> + + <span class="identifier">Base</span><span class="special">&</span> <span class="keyword">operator</span><span class="special">=(</span><span class="identifier">BOOST_RV_REF</span><span class="special">(</span><span class="identifier">Base</span><span class="special">)</span> <span class="identifier">x</span><span class="special">)</span> + <span class="special">{/**/</span> <span class="keyword">return</span> <span class="special">*</span><span class="keyword">this</span><span class="special">;}</span> <span class="comment">// Move assign</span> + + <span class="identifier">Base</span><span class="special">&</span> <span class="keyword">operator</span><span class="special">=(</span><span class="identifier">BOOST_COPY_ASSIGN_REF</span><span class="special">(</span><span class="identifier">Base</span><span class="special">)</span> <span class="identifier">x</span><span class="special">)</span> + <span class="special">{/**/</span> <span class="keyword">return</span> <span class="special">*</span><span class="keyword">this</span><span class="special">;}</span> <span class="comment">// Copy assign</span> + + <span class="keyword">virtual</span> <span class="identifier">Base</span> <span class="special">*</span><span class="identifier">clone</span><span class="special">()</span> <span class="keyword">const</span> + <span class="special">{</span> <span class="keyword">return</span> <span class="keyword">new</span> <span class="identifier">Base</span><span class="special">(*</span><span class="keyword">this</span><span class="special">);</span> <span class="special">}</span> +<span class="special">};</span> + +<span class="keyword">class</span> <span class="identifier">Member</span> +<span class="special">{</span> + <span class="identifier">BOOST_COPYABLE_AND_MOVABLE</span><span class="special">(</span><span class="identifier">Member</span><span class="special">)</span> + + <span class="keyword">public</span><span class="special">:</span> + <span class="identifier">Member</span><span class="special">(){}</span> + + <span class="comment">// Compiler-generated copy constructor...</span> + + <span class="identifier">Member</span><span class="special">(</span><span class="identifier">BOOST_RV_REF</span><span class="special">(</span><span class="identifier">Member</span><span class="special">))</span> <span class="special">{/**/}</span> <span class="comment">// Move ctor</span> + + <span class="identifier">Member</span> <span class="special">&</span><span class="keyword">operator</span><span class="special">=(</span><span class="identifier">BOOST_RV_REF</span><span class="special">(</span><span class="identifier">Member</span><span class="special">))</span> <span class="comment">// Move assign</span> + <span class="special">{/**/</span> <span class="keyword">return</span> <span class="special">*</span><span class="keyword">this</span><span class="special">;</span> <span class="special">}</span> + + <span class="identifier">Member</span> <span class="special">&</span><span class="keyword">operator</span><span class="special">=(</span><span class="identifier">BOOST_COPY_ASSIGN_REF</span><span class="special">(</span><span class="identifier">Member</span><span class="special">))</span> <span class="comment">// Copy assign</span> + <span class="special">{/**/</span> <span class="keyword">return</span> <span class="special">*</span><span class="keyword">this</span><span class="special">;</span> <span class="special">}</span> +<span class="special">};</span> + +<span class="keyword">class</span> <span class="identifier">Derived</span> <span class="special">:</span> <span class="keyword">public</span> <span class="identifier">Base</span> +<span class="special">{</span> + <span class="identifier">BOOST_COPYABLE_AND_MOVABLE</span><span class="special">(</span><span class="identifier">Derived</span><span class="special">)</span> + <span class="identifier">Member</span> <span class="identifier">mem_</span><span class="special">;</span> + + <span class="keyword">public</span><span class="special">:</span> + <span class="identifier">Derived</span><span class="special">(){}</span> + + <span class="comment">// Compiler-generated copy constructor...</span> + + <span class="identifier">Derived</span><span class="special">(</span><span class="identifier">BOOST_RV_REF</span><span class="special">(</span><span class="identifier">Derived</span><span class="special">)</span> <span class="identifier">x</span><span class="special">)</span> <span class="comment">// Move ctor</span> + <span class="special">:</span> <span class="identifier">Base</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="keyword">static_cast</span><span class="special"><</span><span class="identifier">Base</span><span class="special">&>(</span><span class="identifier">x</span><span class="special">))),</span> + <span class="identifier">mem_</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">x</span><span class="special">.</span><span class="identifier">mem_</span><span class="special">))</span> <span class="special">{</span> <span class="special">}</span> + + <span class="identifier">Derived</span><span class="special">&</span> <span class="keyword">operator</span><span class="special">=(</span><span class="identifier">BOOST_RV_REF</span><span class="special">(</span><span class="identifier">Derived</span><span class="special">)</span> <span class="identifier">x</span><span class="special">)</span> <span class="comment">// Move assign</span> + <span class="special">{</span> + <span class="identifier">Base</span><span class="special">::</span><span class="keyword">operator</span><span class="special">=(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="keyword">static_cast</span><span class="special"><</span><span class="identifier">Base</span><span class="special">&>(</span><span class="identifier">x</span><span class="special">)));</span> + <span class="identifier">mem_</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">x</span><span class="special">.</span><span class="identifier">mem_</span><span class="special">);</span> + <span class="keyword">return</span> <span class="special">*</span><span class="keyword">this</span><span class="special">;</span> + <span class="special">}</span> + + <span class="identifier">Derived</span><span class="special">&</span> <span class="keyword">operator</span><span class="special">=(</span><span class="identifier">BOOST_COPY_ASSIGN_REF</span><span class="special">(</span><span class="identifier">Derived</span><span class="special">)</span> <span class="identifier">x</span><span class="special">)</span> <span class="comment">// Copy assign</span> + <span class="special">{</span> + <span class="identifier">Base</span><span class="special">::</span><span class="keyword">operator</span><span class="special">=(</span><span class="keyword">static_cast</span><span class="special"><</span><span class="keyword">const</span> <span class="identifier">Base</span><span class="special">&>(</span><span class="identifier">x</span><span class="special">));</span> + <span class="identifier">mem_</span> <span class="special">=</span> <span class="identifier">x</span><span class="special">.</span><span class="identifier">mem_</span><span class="special">;</span> + <span class="keyword">return</span> <span class="special">*</span><span class="keyword">this</span><span class="special">;</span> + <span class="special">}</span> + <span class="comment">// ...</span> +<span class="special">};</span> +</pre> +<p> + </p> +<div class="important"><table border="0" summary="Important"> +<tr> +<td rowspan="2" align="center" valign="top" width="25"><img alt="[Important]" src="../../../doc/src/images/important.png"></td> +<th align="left">Important</th> +</tr> +<tr><td align="left" valign="top"><p> + Due to limitations in the emulation code, a cast to <code class="computeroutput"><span class="identifier">Base</span> + <span class="special">&</span></code> is needed before moving the + base part in the move constructor and call Base's move constructor instead + of the copy constructor. + </p></td></tr> +</table></div> +<p> + Each subobject will now be treated individually, calling move to bind to the + subobject's move constructors and move assignment operators. <code class="computeroutput"><span class="identifier">Member</span></code> has move operations coded (just like + our earlier <code class="computeroutput"><span class="identifier">clone_ptr</span></code> example) + which will completely avoid the tremendously more expensive copy operations: + </p> +<p> +</p> +<pre class="programlisting"><span class="identifier">Derived</span> <span class="identifier">d</span><span class="special">;</span> +<span class="identifier">Derived</span> <span class="identifier">d2</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">d</span><span class="special">));</span> +<span class="identifier">d2</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">d</span><span class="special">);</span> +</pre> +<p> + </p> +<p> + Note above that the argument x is treated as a lvalue reference. That's why + it is necessary to say <code class="computeroutput"><span class="identifier">move</span><span class="special">(</span><span class="identifier">x</span><span class="special">)</span></code> + instead of just x when passing down to the base class. This is a key safety + feature of move semantics designed to prevent accidently moving twice from + some named variable. All moves from lvalues occur explicitly. + </p> +</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 © 2008-2010 Ion Gaztanaga<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> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="implementing_movable_classes.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="movable_only_classes.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/move/construct_forwarding.html b/doc/html/move/construct_forwarding.html new file mode 100755 index 0000000000..64af21a09e --- /dev/null +++ b/doc/html/move/construct_forwarding.html @@ -0,0 +1,171 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Constructor Forwarding</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../move.html" title="Chapter 16. Boost.Move"> +<link rel="prev" href="move_and_containers.html" title="Containers and move semantics"> +<link rel="next" href="move_iterator.html" title="Move iterators"> +</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="move_and_containers.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="move_iterator.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="move.construct_forwarding"></a><a class="link" href="construct_forwarding.html" title="Constructor Forwarding">Constructor Forwarding</a> +</h2></div></div></div> +<p> + Consider writing a generic factory function that returns an object for a newly + constructed generic type. Factory functions such as this are valuable for encapsulating + and localizing the allocation of resources. Obviously, the factory function + must accept exactly the same sets of arguments as the constructors of the type + of objects constructed: + </p> +<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="identifier">T</span><span class="special">*</span> <span class="identifier">factory_new</span><span class="special">()</span> +<span class="special">{</span> <span class="keyword">return</span> <span class="keyword">new</span> <span class="identifier">T</span><span class="special">();</span> <span class="special">}</span> + +<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="identifier">T</span><span class="special">*</span> <span class="identifier">factory_new</span><span class="special">(</span><span class="identifier">a1</span><span class="special">)</span> +<span class="special">{</span> <span class="keyword">return</span> <span class="keyword">new</span> <span class="identifier">T</span><span class="special">(</span><span class="identifier">a1</span><span class="special">);</span> <span class="special">}</span> + +<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="identifier">T</span><span class="special">*</span> <span class="identifier">factory_new</span><span class="special">(</span><span class="identifier">a1</span><span class="special">,</span> <span class="identifier">a2</span><span class="special">)</span> +<span class="special">{</span> <span class="keyword">return</span> <span class="keyword">new</span> <span class="identifier">T</span><span class="special">(</span><span class="identifier">a1</span><span class="special">,</span> <span class="identifier">a2</span><span class="special">);</span> <span class="special">}</span> +</pre> +<p> + Unfortunately, in C++03 the much bigger issue with this approach is that the + N-argument case would require 2^N overloads, immediately discounting this as + a general solution. Fortunately, most constructors take arguments by value, + by const-reference or by rvalue reference. If these limitations are accepted, + the forwarding emulation of a N-argument case requires just N overloads. This + library makes this emulation easy with the help of <code class="computeroutput"><span class="identifier">BOOST_FWD_REF</span></code> + and <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">forward</span></code>: + </p> +<p> +</p> +<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">move</span><span class="special">/</span><span class="identifier">move</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> + +<span class="keyword">class</span> <span class="identifier">copyable_only_tester</span> +<span class="special">{</span> + <span class="keyword">public</span><span class="special">:</span> + <span class="identifier">copyable_only_tester</span><span class="special">()</span> + <span class="special">{</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"copyable_only_tester()"</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> <span class="special">}</span> + + <span class="identifier">copyable_only_tester</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">copyable_only_tester</span><span class="special">&)</span> + <span class="special">{</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"copyable_only_tester(const copyable_only_tester&)"</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> <span class="special">}</span> + + <span class="identifier">copyable_only_tester</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span> + <span class="special">{</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"copyable_only_tester(int)"</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> <span class="special">}</span> + + <span class="identifier">copyable_only_tester</span><span class="special">(</span><span class="keyword">int</span><span class="special">,</span> <span class="keyword">double</span><span class="special">)</span> + <span class="special">{</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"copyable_only_tester(int, double)"</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> <span class="special">}</span> +<span class="special">};</span> + +<span class="keyword">class</span> <span class="identifier">copyable_movable_tester</span> +<span class="special">{</span> + <span class="comment">// move semantics</span> + <span class="identifier">BOOST_COPYABLE_AND_MOVABLE</span><span class="special">(</span><span class="identifier">copyable_movable_tester</span><span class="special">)</span> + <span class="keyword">public</span><span class="special">:</span> + + <span class="identifier">copyable_movable_tester</span><span class="special">()</span> + <span class="special">{</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"copyable_movable_tester()"</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> <span class="special">}</span> + + <span class="identifier">copyable_movable_tester</span><span class="special">(</span><span class="keyword">int</span><span class="special">)</span> + <span class="special">{</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"copyable_movable_tester(int)"</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> <span class="special">}</span> + + <span class="identifier">copyable_movable_tester</span><span class="special">(</span><span class="identifier">BOOST_RV_REF</span><span class="special">(</span><span class="identifier">copyable_movable_tester</span><span class="special">))</span> + <span class="special">{</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"copyable_movable_tester(BOOST_RV_REF(copyable_movable_tester))"</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> <span class="special">}</span> + + <span class="identifier">copyable_movable_tester</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">copyable_movable_tester</span> <span class="special">&)</span> + <span class="special">{</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"copyable_movable_tester(const copyable_movable_tester &)"</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> <span class="special">}</span> + + <span class="identifier">copyable_movable_tester</span><span class="special">(</span><span class="identifier">BOOST_RV_REF</span><span class="special">(</span><span class="identifier">copyable_movable_tester</span><span class="special">),</span> <span class="identifier">BOOST_RV_REF</span><span class="special">(</span><span class="identifier">copyable_movable_tester</span><span class="special">))</span> + <span class="special">{</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"copyable_movable_tester(BOOST_RV_REF(copyable_movable_tester), BOOST_RV_REF(copyable_movable_tester))"</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> <span class="special">}</span> + + <span class="identifier">copyable_movable_tester</span> <span class="special">&</span><span class="keyword">operator</span><span class="special">=(</span><span class="identifier">BOOST_RV_REF</span><span class="special">(</span><span class="identifier">copyable_movable_tester</span><span class="special">))</span> + <span class="special">{</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"copyable_movable_tester & operator=(BOOST_RV_REF(copyable_movable_tester))"</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> + <span class="keyword">return</span> <span class="special">*</span><span class="keyword">this</span><span class="special">;</span> <span class="special">}</span> + + <span class="identifier">copyable_movable_tester</span> <span class="special">&</span><span class="keyword">operator</span><span class="special">=(</span><span class="identifier">BOOST_COPY_ASSIGN_REF</span><span class="special">(</span><span class="identifier">copyable_movable_tester</span><span class="special">))</span> + <span class="special">{</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"copyable_movable_tester & operator=(BOOST_COPY_ASSIGN_REF(copyable_movable_tester))"</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> + <span class="keyword">return</span> <span class="special">*</span><span class="keyword">this</span><span class="special">;</span> <span class="special">}</span> +<span class="special">};</span> + +<span class="comment">//1 argument</span> +<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">MaybeMovable</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">MaybeRv</span><span class="special">></span> +<span class="keyword">void</span> <span class="identifier">function_construct</span><span class="special">(</span><span class="identifier">BOOST_FWD_REF</span><span class="special">(</span><span class="identifier">MaybeRv</span><span class="special">)</span> <span class="identifier">x</span><span class="special">)</span> +<span class="special">{</span> <span class="identifier">MaybeMovable</span> <span class="identifier">m</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">forward</span><span class="special"><</span><span class="identifier">MaybeRv</span><span class="special">>(</span><span class="identifier">x</span><span class="special">));</span> <span class="special">}</span> + +<span class="comment">//2 argument</span> +<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">MaybeMovable</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">MaybeRv</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">MaybeRv2</span><span class="special">></span> +<span class="keyword">void</span> <span class="identifier">function_construct</span><span class="special">(</span><span class="identifier">BOOST_FWD_REF</span><span class="special">(</span><span class="identifier">MaybeRv</span><span class="special">)</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">BOOST_FWD_REF</span><span class="special">(</span><span class="identifier">MaybeRv2</span><span class="special">)</span> <span class="identifier">x2</span><span class="special">)</span> +<span class="special">{</span> <span class="identifier">MaybeMovable</span> <span class="identifier">m</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">forward</span><span class="special"><</span><span class="identifier">MaybeRv</span><span class="special">>(</span><span class="identifier">x</span><span class="special">),</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">forward</span><span class="special"><</span><span class="identifier">MaybeRv2</span><span class="special">>(</span><span class="identifier">x2</span><span class="special">));</span> <span class="special">}</span> + +<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> +<span class="special">{</span> + <span class="identifier">copyable_movable_tester</span> <span class="identifier">m</span><span class="special">;</span> + <span class="comment">//move constructor</span> + <span class="identifier">function_construct</span><span class="special"><</span><span class="identifier">copyable_movable_tester</span><span class="special">>(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">m</span><span class="special">));</span> + <span class="comment">//copy constructor</span> + <span class="identifier">function_construct</span><span class="special"><</span><span class="identifier">copyable_movable_tester</span><span class="special">>(</span><span class="identifier">copyable_movable_tester</span><span class="special">());</span> + <span class="comment">//two rvalue constructor</span> + <span class="identifier">function_construct</span><span class="special"><</span><span class="identifier">copyable_movable_tester</span><span class="special">>(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">m</span><span class="special">),</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">m</span><span class="special">));</span> + + <span class="identifier">copyable_only_tester</span> <span class="identifier">nm</span><span class="special">;</span> + <span class="comment">//copy constructor (copyable_only_tester has no move ctor.)</span> + <span class="identifier">function_construct</span><span class="special"><</span><span class="identifier">copyable_only_tester</span><span class="special">>(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">nm</span><span class="special">));</span> + <span class="comment">//copy constructor</span> + <span class="identifier">function_construct</span><span class="special"><</span><span class="identifier">copyable_only_tester</span><span class="special">>(</span><span class="identifier">nm</span><span class="special">);</span> + <span class="comment">//int constructor</span> + <span class="identifier">function_construct</span><span class="special"><</span><span class="identifier">copyable_only_tester</span><span class="special">>(</span><span class="keyword">int</span><span class="special">(</span><span class="number">0</span><span class="special">));</span> + <span class="comment">//int, double constructor</span> + <span class="identifier">function_construct</span><span class="special"><</span><span class="identifier">copyable_only_tester</span><span class="special">>(</span><span class="keyword">int</span><span class="special">(</span><span class="number">0</span><span class="special">),</span> <span class="keyword">double</span><span class="special">(</span><span class="number">0.0</span><span class="special">));</span> + + <span class="comment">//Output is:</span> + <span class="comment">//copyable_movable_tester()</span> + <span class="comment">//copyable_movable_tester(BOOST_RV_REF(copyable_movable_tester))</span> + <span class="comment">//copyable_movable_tester()</span> + <span class="comment">//copyable_movable_tester(const copyable_movable_tester &)</span> + <span class="comment">//copyable_movable_tester(BOOST_RV_REF(copyable_movable_tester), BOOST_RV_REF(copyable_movable_tester))</span> + <span class="comment">//copyable_only_tester()</span> + <span class="comment">//copyable_only_tester(const copyable_only_tester&)</span> + <span class="comment">//copyable_only_tester(const copyable_only_tester&)</span> + <span class="comment">//copyable_only_tester(int)</span> + <span class="comment">//copyable_only_tester(int, double)</span> + <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> +<span class="special">}</span> +</pre> +<p> + </p> +<p> + Constructor forwarding comes handful to implement placement insertion in containers + with just N overloads if the implementor accepts the limitations of this type + of forwarding for C++03 compilers. In compilers with rvalue references perfect + forwarding is achieved. + </p> +</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 © 2008-2010 Ion Gaztanaga<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> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="move_and_containers.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="move_iterator.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/move/emulation_limitations.html b/doc/html/move/emulation_limitations.html new file mode 100755 index 0000000000..00b0378dda --- /dev/null +++ b/doc/html/move/emulation_limitations.html @@ -0,0 +1,197 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Emulation limitations</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../move.html" title="Chapter 16. Boost.Move"> +<link rel="prev" href="move_algorithms.html" title="Move algorithms"> +<link rel="next" href="how_the_library_works.html" title="How the library works"> +</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="move_algorithms.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="how_the_library_works.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="move.emulation_limitations"></a><a class="link" href="emulation_limitations.html" title="Emulation limitations">Emulation limitations</a> +</h2></div></div></div> +<div class="toc"><dl> +<dt><span class="section"><a href="emulation_limitations.html#move.emulation_limitations.emulation_limitations_base">Initializing + base classes</a></span></dt> +<dt><span class="section"><a href="emulation_limitations.html#move.emulation_limitations.template_parameters">Template + parameters for perfect forwarding</a></span></dt> +<dt><span class="section"><a href="emulation_limitations.html#move.emulation_limitations.emulation_limitations_binding">Binding + of rvalue references to lvalues</a></span></dt> +<dt><span class="section"><a href="emulation_limitations.html#move.emulation_limitations.assignment_operator">Assignment + operator in classes derived from or holding copyable and movable types</a></span></dt> +</dl></div> +<p> + Like any emulation effort, the library has some limitations users should take + in care to achieve portable and efficient code when using the library with + C++03 conformant compilers: + </p> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="move.emulation_limitations.emulation_limitations_base"></a><a class="link" href="emulation_limitations.html#move.emulation_limitations.emulation_limitations_base" title="Initializing base classes">Initializing + base classes</a> +</h3></div></div></div> +<p> + When initializing base classes in move constructors, users must cast the + reference to a base class reference before moving it. Example: + </p> +<pre class="programlisting"><span class="comment">//Portable and efficient</span> +<span class="identifier">Derived</span><span class="special">(</span><span class="identifier">BOOST_RV_REF</span><span class="special">(</span><span class="identifier">Derived</span><span class="special">)</span> <span class="identifier">x</span><span class="special">)</span> <span class="comment">// Move ctor</span> + <span class="special">:</span> <span class="identifier">Base</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="keyword">static_cast</span><span class="special"><</span><span class="identifier">Base</span><span class="special">&>(</span><span class="identifier">x</span><span class="special">))),</span> + <span class="identifier">mem_</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">x</span><span class="special">.</span><span class="identifier">mem_</span><span class="special">))</span> <span class="special">{</span> <span class="special">}</span> +</pre> +<p> + If casting is not performed the emulation will not move construct the base + class, because no conversion is available from <code class="computeroutput"><span class="identifier">BOOST_RV_REF</span><span class="special">(</span><span class="identifier">Derived</span><span class="special">)</span></code> to <code class="computeroutput"><span class="identifier">BOOST_RV_REF</span><span class="special">(</span><span class="identifier">Base</span><span class="special">)</span></code>. + Without the cast we might obtain a compilation error (for non-copyable types) + or a less-efficient move constructor (for copyable types): + </p> +<pre class="programlisting"><span class="comment">//If Derived is copyable, then Base is copy-constructed.</span> +<span class="comment">//If not, a compilation error is issued</span> +<span class="identifier">Derived</span><span class="special">(</span><span class="identifier">BOOST_RV_REF</span><span class="special">(</span><span class="identifier">Derived</span><span class="special">)</span> <span class="identifier">x</span><span class="special">)</span> <span class="comment">// Move ctor</span> + <span class="special">:</span> <span class="identifier">Base</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">x</span><span class="special">)),</span> + <span class="identifier">mem_</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">x</span><span class="special">.</span><span class="identifier">mem_</span><span class="special">))</span> <span class="special">{</span> <span class="special">}</span> +</pre> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="move.emulation_limitations.template_parameters"></a><a class="link" href="emulation_limitations.html#move.emulation_limitations.template_parameters" title="Template parameters for perfect forwarding">Template + parameters for perfect forwarding</a> +</h3></div></div></div> +<p> + The emulation can't deal with C++0x reference collapsing rules that allow + perfect forwarding: + </p> +<pre class="programlisting"><span class="comment">//C++0x</span> +<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> +<span class="keyword">void</span> <span class="identifier">forward_function</span><span class="special">(</span><span class="identifier">T</span> <span class="special">&&</span><span class="identifier">t</span><span class="special">)</span> +<span class="special">{</span> <span class="identifier">inner_function</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">forward</span><span class="special"><</span><span class="identifier">T</span><span class="special">>(</span><span class="identifier">t</span><span class="special">);</span> <span class="special">}</span> + +<span class="comment">//Wrong C++03 emulation</span> +<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> +<span class="keyword">void</span> <span class="identifier">forward_function</span><span class="special">(</span><span class="identifier">BOOST_RV_REF</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">t</span><span class="special">)</span> +<span class="special">{</span> <span class="identifier">inner_function</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">forward</span><span class="special"><</span><span class="identifier">T</span><span class="special">>(</span><span class="identifier">t</span><span class="special">);</span> <span class="special">}</span> +</pre> +<p> + In C++03 emulation BOOST_RV_REF doesn't catch any const rlvalues. For more + details on forwarding see <a class="link" href="construct_forwarding.html" title="Constructor Forwarding">Constructor + Forwarding</a> chapter. + </p> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="move.emulation_limitations.emulation_limitations_binding"></a><a class="link" href="emulation_limitations.html#move.emulation_limitations.emulation_limitations_binding" title="Binding of rvalue references to lvalues">Binding + of rvalue references to lvalues</a> +</h3></div></div></div> +<p> + The <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2004/n1690.html" target="_top">first + rvalue reference</a> proposal allowed the binding of rvalue references + to lvalues: + </p> +<pre class="programlisting"><span class="identifier">func</span><span class="special">(</span><span class="identifier">Type</span> <span class="special">&&</span><span class="identifier">t</span><span class="special">);</span> +<span class="comment">//....</span> + +<span class="identifier">Type</span> <span class="identifier">t</span><span class="special">;</span> <span class="comment">//Allowed</span> +<span class="identifier">func</span><span class="special">(</span><span class="identifier">t</span><span class="special">)</span> +</pre> +<p> + Later, as explained in <a href="http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2008/n2812.html" target="_top"><span class="emphasis"><em>Fixing + a Safety Problem with Rvalue References</em></span></a> this behaviour + was considered dangerous and eliminated this binding so that rvalue references + adhere to the principle of type-safe overloading: <span class="emphasis"><em>Every function + must be type-safe in isolation, without regard to how it has been overloaded</em></span> + </p> +<p> + <span class="bold"><strong>Boost.Move</strong></span> can't emulate this type-safe + overloading principle for C++03 compilers: + </p> +<pre class="programlisting"><span class="comment">//Allowed by move emulation</span> +<span class="identifier">movable</span> <span class="identifier">m</span><span class="special">;</span> +<span class="identifier">BOOST_RV_REF</span><span class="special">(</span><span class="identifier">movable</span><span class="special">)</span> <span class="identifier">r</span> <span class="special">=</span> <span class="identifier">m</span><span class="special">;</span> +</pre> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="move.emulation_limitations.assignment_operator"></a><a class="link" href="emulation_limitations.html#move.emulation_limitations.assignment_operator" title="Assignment operator in classes derived from or holding copyable and movable types">Assignment + operator in classes derived from or holding copyable and movable types</a> +</h3></div></div></div> +<p> + The macro <code class="computeroutput"><a class="link" href="../BOOST_COPYABLE_AND_MOVABLE.html" title="Macro BOOST_COPYABLE_AND_MOVABLE">BOOST_COPYABLE_AND_MOVABLE</a></code> + needs to define a copy constructor for <code class="computeroutput"><span class="identifier">copyable_and_movable</span></code> + taking a non-const parameter in C++03 compilers: + </p> +<pre class="programlisting"><span class="comment">//Generated by BOOST_COPYABLE_AND_MOVABLE</span> +<span class="identifier">copyable_and_movable</span> <span class="special">&</span><span class="keyword">operator</span><span class="special">=(</span><span class="identifier">copyable_and_movable</span><span class="special">&){/**/}</span> +</pre> +<p> + Since the non-const overload of the copy constructor is generated, compiler-generated + assignment operators for classes containing <code class="computeroutput"><span class="identifier">copyable_and_movable</span></code> + will get the non-const copy constructor overload, which will surely surprise + users: + </p> +<pre class="programlisting"><span class="keyword">class</span> <span class="identifier">holder</span> +<span class="special">{</span> + <span class="identifier">copyable_and_movable</span> <span class="identifier">c</span><span class="special">;</span> +<span class="special">};</span> + +<span class="keyword">void</span> <span class="identifier">func</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">holder</span><span class="special">&</span> <span class="identifier">h</span><span class="special">)</span> +<span class="special">{</span> + <span class="identifier">holder</span> <span class="identifier">copy_h</span><span class="special">(</span><span class="identifier">h</span><span class="special">);</span> <span class="comment">//<--- ERROR: can't convert 'const holder&' to 'holder&'</span> + <span class="comment">//Compiler-generated copy constructor is non-const:</span> + <span class="comment">// holder& operator(holder &)</span> + <span class="comment">//!!!</span> +<span class="special">}</span> +</pre> +<p> + This limitation forces the user to define a const version of the copy assignment, + in all classes holding copyable and movable classes which might annoying + in some cases. + </p> +<p> + An alternative is to implement a single <code class="computeroutput"><span class="keyword">operator</span> + <span class="special">=()</span></code> for copyable and movable classes + <a href="http://cpp-next.com/archive/2009/08/want-speed-pass-by-value/" target="_top">using + "pass by value" semantics</a>: + </p> +<pre class="programlisting"><span class="identifier">T</span><span class="special">&</span> <span class="keyword">operator</span><span class="special">=(</span><span class="identifier">T</span> <span class="identifier">x</span><span class="special">)</span> <span class="comment">// x is a copy of the source; hard work already done</span> +<span class="special">{</span> + <span class="identifier">swap</span><span class="special">(*</span><span class="keyword">this</span><span class="special">,</span> <span class="identifier">x</span><span class="special">);</span> <span class="comment">// trade our resources for x's</span> + <span class="keyword">return</span> <span class="special">*</span><span class="keyword">this</span><span class="special">;</span> <span class="comment">// our (old) resources get destroyed with x</span> +<span class="special">}</span> +</pre> +<p> + However, "pass by value" is not optimal for classes (like containers, + strings, etc.) that reuse resources (like previously allocated memory) when + x is assigned from a lvalue. + </p> +</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 © 2008-2010 Ion Gaztanaga<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> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="move_algorithms.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="how_the_library_works.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/move/how_the_library_works.html b/doc/html/move/how_the_library_works.html new file mode 100755 index 0000000000..069ed90c09 --- /dev/null +++ b/doc/html/move/how_the_library_works.html @@ -0,0 +1,180 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>How the library works</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../move.html" title="Chapter 16. Boost.Move"> +<link rel="prev" href="emulation_limitations.html" title="Emulation limitations"> +<link rel="next" href="thanks_to.html" title="Thanks and credits"> +</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="emulation_limitations.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="thanks_to.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="move.how_the_library_works"></a><a class="link" href="how_the_library_works.html" title="How the library works">How the library works</a> +</h2></div></div></div> +<p> + <span class="bold"><strong>Boost.Move</strong></span> is based on macros that are expanded + to true rvalue references in C++0x compilers and emulated rvalue reference + classes and conversion operators in C++03 compilers. + </p> +<p> + In C++03 compilers <span class="bold"><strong>Boost.Move</strong></span> defines a class + named <code class="computeroutput"><span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rv</span></code>: + </p> +<pre class="programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> +<span class="keyword">class</span> <span class="identifier">rv</span> <span class="special">:</span> <span class="keyword">public</span> <span class="identifier">T</span> +<span class="special">{</span> + <span class="identifier">rv</span><span class="special">();</span> + <span class="special">~</span><span class="identifier">rv</span><span class="special">();</span> + <span class="identifier">rv</span><span class="special">(</span><span class="identifier">rv</span> <span class="keyword">const</span><span class="special">&);</span> + <span class="keyword">void</span> <span class="keyword">operator</span><span class="special">=(</span><span class="identifier">rv</span> <span class="keyword">const</span><span class="special">&);</span> +<span class="special">};</span> +</pre> +<p> + which is convertible to the movable base class (usual C++ derived to base conversion). + When users mark their classes as <code class="computeroutput"><a class="link" href="../BOOST_MOVABLE_BUT_NOT_COPYABLE.html" title="Macro BOOST_MOVABLE_BUT_NOT_COPYABLE">BOOST_MOVABLE_BUT_NOT_COPYABLE</a></code> + or <code class="computeroutput"><a class="link" href="../BOOST_COPYABLE_AND_MOVABLE.html" title="Macro BOOST_COPYABLE_AND_MOVABLE">BOOST_COPYABLE_AND_MOVABLE</a></code>, + these macros define conversion operators to references to <code class="computeroutput"><span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rv</span></code>: + </p> +<pre class="programlisting"><span class="preprocessor">#define</span> <span class="identifier">BOOST_MOVABLE_BUT_NOT_COPYABLE</span><span class="special">(</span><span class="identifier">TYPE</span><span class="special">)\</span> + <span class="keyword">public</span><span class="special">:\</span> + <span class="keyword">operator</span> <span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rv</span><span class="special"><</span><span class="identifier">TYPE</span><span class="special">>&()</span> <span class="special">\</span> + <span class="special">{</span> <span class="keyword">return</span> <span class="special">*</span><span class="keyword">static_cast</span><span class="special"><</span> <span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rv</span><span class="special"><</span><span class="identifier">TYPE</span><span class="special">>*</span> <span class="special">>(</span><span class="keyword">this</span><span class="special">);</span> <span class="special">}\</span> + <span class="keyword">operator</span> <span class="keyword">const</span> <span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rv</span><span class="special"><</span><span class="identifier">TYPE</span><span class="special">>&()</span> <span class="keyword">const</span> <span class="special">\</span> + <span class="special">{</span> <span class="keyword">return</span> <span class="keyword">static_cast</span><span class="special"><</span><span class="keyword">const</span> <span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rv</span><span class="special"><</span><span class="identifier">TYPE</span><span class="special">>*</span> <span class="special">>(</span><span class="keyword">this</span><span class="special">);</span> <span class="special">}\</span> + <span class="keyword">private</span><span class="special">:\</span> + <span class="comment">//More stuff...</span> +</pre> +<p> + <code class="computeroutput"><a class="link" href="../BOOST_MOVABLE_BUT_NOT_COPYABLE.html" title="Macro BOOST_MOVABLE_BUT_NOT_COPYABLE">BOOST_MOVABLE_BUT_NOT_COPYABLE</a></code> + also declares a private copy constructor and assignment. <code class="computeroutput"><a class="link" href="../BOOST_COPYABLE_AND_MOVABLE.html" title="Macro BOOST_COPYABLE_AND_MOVABLE">BOOST_COPYABLE_AND_MOVABLE</a></code> + defines a non-const copy constructor <code class="computeroutput"><span class="identifier">TYPE</span> + <span class="special">&</span><span class="keyword">operator</span><span class="special">=(</span><span class="identifier">TYPE</span><span class="special">&)</span></code> + that forwards to a const version: + </p> +<pre class="programlisting"><span class="preprocessor">#define</span> <span class="identifier">BOOST_COPYABLE_AND_MOVABLE</span><span class="special">(</span><span class="identifier">TYPE</span><span class="special">)\</span> + <span class="keyword">public</span><span class="special">:\</span> + <span class="identifier">TYPE</span><span class="special">&</span> <span class="keyword">operator</span><span class="special">=(</span><span class="identifier">TYPE</span> <span class="special">&</span><span class="identifier">t</span><span class="special">)\</span> + <span class="special">{</span> <span class="keyword">this</span><span class="special">-></span><span class="keyword">operator</span><span class="special">=(</span><span class="keyword">static_cast</span><span class="special"><</span><span class="keyword">const</span> <span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rv</span><span class="special"><</span><span class="identifier">TYPE</span><span class="special">></span> <span class="special">&>(</span><span class="keyword">const_cast</span><span class="special"><</span><span class="keyword">const</span> <span class="identifier">TYPE</span> <span class="special">&>(</span><span class="identifier">t</span><span class="special">)));</span> <span class="keyword">return</span> <span class="special">*</span><span class="keyword">this</span><span class="special">;}\</span> + <span class="comment">//More stuff...</span> +</pre> +<p> + In C++0x compilers <code class="computeroutput"><span class="identifier">BOOST_COPYABLE_AND_MOVABLE</span></code> + expands to nothing and <code class="computeroutput"><span class="identifier">BOOST_MOVABLE_BUT_NOT_COPYABLE</span></code> + declares copy constructor and assigment operator private. + </p> +<p> + When users define the <code class="computeroutput"><a class="link" href="../BOOST_RV_REF.html" title="Macro BOOST_RV_REF">BOOST_RV_REF</a></code> + overload of a copy constructor/assignment, in C++0x compilers it is expanded + to a rvalue reference (<code class="computeroutput"><span class="identifier">T</span><span class="special">&&</span></code>) + overload and in C++03 compilers it is expanded to a <code class="computeroutput"><span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rv</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> + <span class="special">&</span></code> overload: + </p> +<pre class="programlisting"><span class="preprocessor">#define</span> <span class="identifier">BOOST_RV_REF</span><span class="special">(</span><span class="identifier">TYPE</span><span class="special">)</span> <span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rv</span><span class="special"><</span> <span class="identifier">TYPE</span> <span class="special">>&</span> <span class="special">\</span> +</pre> +<p> + When users define the <code class="computeroutput"><a class="link" href="../BOOST_COPY_ASSIGN_REF.html" title="Macro BOOST_COPY_ASSIGN_REF">BOOST_COPY_ASSIGN_REF</a></code> + overload, it is expanded to a usual copy assignment (<code class="computeroutput"><span class="keyword">const</span> + <span class="identifier">T</span> <span class="special">&</span></code>) + overload in C++0x compilers and to a <code class="computeroutput"><span class="keyword">const</span> + <span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rv</span> <span class="special">&</span></code> + overload in C++03 compilers: + </p> +<pre class="programlisting"><span class="preprocessor">#define</span> <span class="identifier">BOOST_COPY_ASSIGN_REF</span><span class="special">(</span><span class="identifier">TYPE</span><span class="special">)</span> <span class="keyword">const</span> <span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rv</span><span class="special"><</span> <span class="identifier">TYPE</span> <span class="special">>&</span> +</pre> +<p> + As seen, in <span class="bold"><strong>Boost.Move</strong></span> generates efficient + and clean code for C++0x move semantics, without modifying any resolution overload. + For C++03 compilers when overload resolution is performed these are the bindings: + </p> +<div class="itemizedlist"><ul class="itemizedlist" type="disc"> +<li class="listitem"> + a) non-const rvalues (e.g.: temporaries), bind to <code class="computeroutput"><span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rv</span><span class="special"><</span> <span class="identifier">TYPE</span> <span class="special">>&</span></code> + </li> +<li class="listitem"> + b) const rvalue and lvalues, bind to <code class="computeroutput"><span class="keyword">const</span> + <span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rv</span><span class="special"><</span> <span class="identifier">TYPE</span> <span class="special">>&</span></code> + </li> +<li class="listitem"> + c) non-const lvalues (e.g. non-const references) bind to <code class="computeroutput"><span class="identifier">TYPE</span><span class="special">&</span></code> + </li> +</ul></div> +<p> + The library does not define the equivalent of <code class="computeroutput"><a class="link" href="../BOOST_COPY_ASSIGN_REF.html" title="Macro BOOST_COPY_ASSIGN_REF">BOOST_COPY_ASSIGN_REF</a></code> + for copy construction (say, <code class="computeroutput"><span class="identifier">BOOST_COPY_CTOR_REF</span></code>) + because nearly all modern compilers implement RVO and this is much more efficient + than any move emulation. <code class="computeroutput"><a class="link" href="../boost/move_id1117957.html" title="Function template move">move</a></code> + just casts <code class="computeroutput"><span class="identifier">TYPE</span> <span class="special">&</span></code> + into <code class="computeroutput"><span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rv</span><span class="special"><</span><span class="identifier">TYPE</span><span class="special">></span> <span class="special">&</span></code>. + </p> +<p> + Here's an example that demostrates how different rlvalue objects bind to <code class="computeroutput"><span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rv</span></code> references in the presence of three overloads + and the conversion operators in C++03 compilers: + </p> +<p> +</p> +<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">move</span><span class="special">/</span><span class="identifier">move</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> + +<span class="keyword">class</span> <span class="identifier">sink_tester</span> +<span class="special">{</span> + <span class="keyword">public</span><span class="special">:</span> <span class="comment">//conversions provided by BOOST_COPYABLE_AND_MOVABLE</span> + <span class="keyword">operator</span> <span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rv</span><span class="special"><</span><span class="identifier">sink_tester</span><span class="special">>&()</span> + <span class="special">{</span> <span class="keyword">return</span> <span class="special">*</span><span class="keyword">static_cast</span><span class="special"><</span> <span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rv</span><span class="special"><</span><span class="identifier">sink_tester</span><span class="special">>*</span> <span class="special">>(</span><span class="keyword">this</span><span class="special">);</span> <span class="special">}</span> + <span class="keyword">operator</span> <span class="keyword">const</span> <span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rv</span><span class="special"><</span><span class="identifier">sink_tester</span><span class="special">>&()</span> <span class="keyword">const</span> + <span class="special">{</span> <span class="keyword">return</span> <span class="special">*</span><span class="keyword">static_cast</span><span class="special"><</span><span class="keyword">const</span> <span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rv</span><span class="special"><</span><span class="identifier">sink_tester</span><span class="special">>*</span> <span class="special">>(</span><span class="keyword">this</span><span class="special">);</span> <span class="special">}</span> +<span class="special">};</span> + +<span class="comment">//Functions returning different r/lvalue types</span> + <span class="identifier">sink_tester</span> <span class="identifier">rvalue</span><span class="special">()</span> <span class="special">{</span> <span class="keyword">return</span> <span class="identifier">sink_tester</span><span class="special">();</span> <span class="special">}</span> +<span class="keyword">const</span> <span class="identifier">sink_tester</span> <span class="identifier">const_rvalue</span><span class="special">()</span> <span class="special">{</span> <span class="keyword">return</span> <span class="identifier">sink_tester</span><span class="special">();</span> <span class="special">}</span> + <span class="identifier">sink_tester</span> <span class="special">&</span> <span class="identifier">lvalue</span><span class="special">()</span> <span class="special">{</span> <span class="keyword">static</span> <span class="identifier">sink_tester</span> <span class="identifier">lv</span><span class="special">;</span> <span class="keyword">return</span> <span class="identifier">lv</span><span class="special">;</span> <span class="special">}</span> +<span class="keyword">const</span> <span class="identifier">sink_tester</span> <span class="special">&</span> <span class="identifier">const_lvalue</span><span class="special">()</span> <span class="special">{</span> <span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">sink_tester</span> <span class="identifier">clv</span> <span class="special">=</span> <span class="identifier">sink_tester</span><span class="special">();</span> <span class="keyword">return</span> <span class="identifier">clv</span><span class="special">;</span> <span class="special">}</span> + +<span class="comment">//BOOST_RV_REF overload</span> +<span class="keyword">void</span> <span class="identifier">sink</span><span class="special">(::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rv</span><span class="special"><</span><span class="identifier">sink_tester</span><span class="special">></span> <span class="special">&)</span> <span class="special">{</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"non-const rvalue catched"</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> <span class="special">}</span> +<span class="comment">//BOOST_COPY_ASSIGN_REF overload</span> +<span class="keyword">void</span> <span class="identifier">sink</span><span class="special">(</span><span class="keyword">const</span> <span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">rv</span><span class="special"><</span><span class="identifier">sink_tester</span><span class="special">></span> <span class="special">&){</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"const (r-l)value catched"</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> <span class="special">}</span> +<span class="comment">//Overload provided by BOOST_COPYABLE_AND_MOVABLE</span> +<span class="keyword">void</span> <span class="identifier">sink</span><span class="special">(</span><span class="identifier">sink_tester</span> <span class="special">&)</span> <span class="special">{</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"non-const lvalue catched"</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> <span class="special">}</span> + +<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> +<span class="special">{</span> + <span class="identifier">sink</span><span class="special">(</span><span class="identifier">const_rvalue</span><span class="special">());</span> <span class="comment">//"const (r-l)value catched"</span> + <span class="identifier">sink</span><span class="special">(</span><span class="identifier">const_lvalue</span><span class="special">());</span> <span class="comment">//"const (r-l)value catched"</span> + <span class="identifier">sink</span><span class="special">(</span><span class="identifier">lvalue</span><span class="special">());</span> <span class="comment">//"non-const lvalue catched"</span> + <span class="identifier">sink</span><span class="special">(</span><span class="identifier">rvalue</span><span class="special">());</span> <span class="comment">//"non-const rvalue catched"</span> + <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> +<span class="special">}</span> +</pre> +<p> + </p> +</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 © 2008-2010 Ion Gaztanaga<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> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="emulation_limitations.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="thanks_to.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/move/implementing_movable_classes.html b/doc/html/move/implementing_movable_classes.html new file mode 100755 index 0000000000..07fd96ad2c --- /dev/null +++ b/doc/html/move/implementing_movable_classes.html @@ -0,0 +1,246 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Implementing copyable and movable classes</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../move.html" title="Chapter 16. Boost.Move"> +<link rel="prev" href="introduction.html" title="Introduction"> +<link rel="next" href="composition_inheritance.html" title="Composition or inheritance"> +</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="introduction.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="composition_inheritance.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="move.implementing_movable_classes"></a><a class="link" href="implementing_movable_classes.html" title="Implementing copyable and movable classes">Implementing copyable + and movable classes</a> +</h2></div></div></div> +<div class="toc"><dl> +<dt><span class="section"><a href="implementing_movable_classes.html#move.implementing_movable_classes.copyable_and_movable_cpp0x">Copyable + and movable classes in C++0x</a></span></dt> +<dt><span class="section"><a href="implementing_movable_classes.html#move.implementing_movable_classes.copyable_and_movable_cpp03">Copyable + and movable classes in portable syntax for both C++03 and C++0x compilers</a></span></dt> +</dl></div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="move.implementing_movable_classes.copyable_and_movable_cpp0x"></a><a class="link" href="implementing_movable_classes.html#move.implementing_movable_classes.copyable_and_movable_cpp0x" title="Copyable and movable classes in C++0x">Copyable + and movable classes in C++0x</a> +</h3></div></div></div> +<p> + Consider a simple handle class that owns a resource and also provides copy + semantics (copy constructor and assignment). For example a <code class="computeroutput"><span class="identifier">clone_ptr</span></code> might own a pointer, and call + <code class="computeroutput"><span class="identifier">clone</span><span class="special">()</span></code> + on it for copying purposes: + </p> +<pre class="programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> +<span class="keyword">class</span> <span class="identifier">clone_ptr</span> +<span class="special">{</span> + <span class="keyword">private</span><span class="special">:</span> + <span class="identifier">T</span><span class="special">*</span> <span class="identifier">ptr</span><span class="special">;</span> + + <span class="keyword">public</span><span class="special">:</span> + <span class="comment">// construction</span> + <span class="keyword">explicit</span> <span class="identifier">clone_ptr</span><span class="special">(</span><span class="identifier">T</span><span class="special">*</span> <span class="identifier">p</span> <span class="special">=</span> <span class="number">0</span><span class="special">)</span> <span class="special">:</span> <span class="identifier">ptr</span><span class="special">(</span><span class="identifier">p</span><span class="special">)</span> <span class="special">{}</span> + + <span class="comment">// destruction</span> + <span class="special">~</span><span class="identifier">clone_ptr</span><span class="special">()</span> <span class="special">{</span> <span class="keyword">delete</span> <span class="identifier">ptr</span><span class="special">;</span> <span class="special">}</span> + + <span class="comment">// copy semantics</span> + <span class="identifier">clone_ptr</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">clone_ptr</span><span class="special">&</span> <span class="identifier">p</span><span class="special">)</span> + <span class="special">:</span> <span class="identifier">ptr</span><span class="special">(</span><span class="identifier">p</span><span class="special">.</span><span class="identifier">ptr</span> <span class="special">?</span> <span class="identifier">p</span><span class="special">.</span><span class="identifier">ptr</span><span class="special">-></span><span class="identifier">clone</span><span class="special">()</span> <span class="special">:</span> <span class="number">0</span><span class="special">)</span> <span class="special">{}</span> + + <span class="identifier">clone_ptr</span><span class="special">&</span> <span class="keyword">operator</span><span class="special">=(</span><span class="keyword">const</span> <span class="identifier">clone_ptr</span><span class="special">&</span> <span class="identifier">p</span><span class="special">)</span> + <span class="special">{</span> + <span class="keyword">if</span> <span class="special">(</span><span class="keyword">this</span> <span class="special">!=</span> <span class="special">&</span><span class="identifier">p</span><span class="special">)</span> + <span class="special">{</span> + <span class="identifier">T</span> <span class="special">*</span><span class="identifier">p</span> <span class="special">=</span> <span class="identifier">p</span><span class="special">.</span><span class="identifier">ptr</span> <span class="special">?</span> <span class="identifier">p</span><span class="special">.</span><span class="identifier">ptr</span><span class="special">-></span><span class="identifier">clone</span><span class="special">()</span> <span class="special">:</span> <span class="number">0</span><span class="special">;</span> + <span class="keyword">delete</span> <span class="identifier">ptr</span><span class="special">;</span> + <span class="identifier">ptr</span> <span class="special">=</span> <span class="identifier">p</span><span class="special">;</span> + <span class="special">}</span> + <span class="keyword">return</span> <span class="special">*</span><span class="keyword">this</span><span class="special">;</span> + <span class="special">}</span> + + <span class="comment">// move semantics</span> + <span class="identifier">clone_ptr</span><span class="special">(</span><span class="identifier">clone_ptr</span><span class="special">&&</span> <span class="identifier">p</span><span class="special">)</span> + <span class="special">:</span> <span class="identifier">ptr</span><span class="special">(</span><span class="identifier">p</span><span class="special">.</span><span class="identifier">ptr</span><span class="special">)</span> <span class="special">{</span> <span class="identifier">p</span><span class="special">.</span><span class="identifier">ptr</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> <span class="special">}</span> + + <span class="identifier">clone_ptr</span><span class="special">&</span> <span class="keyword">operator</span><span class="special">=(</span><span class="identifier">clone_ptr</span><span class="special">&&</span> <span class="identifier">p</span><span class="special">)</span> + <span class="special">{</span> + <span class="identifier">std</span><span class="special">::</span><span class="identifier">swap</span><span class="special">(</span><span class="identifier">ptr</span><span class="special">,</span> <span class="identifier">p</span><span class="special">.</span><span class="identifier">ptr</span><span class="special">);</span> + <span class="keyword">delete</span> <span class="identifier">p</span><span class="special">.</span><span class="identifier">ptr</span><span class="special">;</span> + <span class="identifier">p</span><span class="special">.</span><span class="identifier">ptr</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> + <span class="keyword">return</span> <span class="special">*</span><span class="keyword">this</span><span class="special">;</span> + <span class="special">}</span> + + <span class="comment">// Other operations...</span> +<span class="special">};</span> +</pre> +<p> + <code class="computeroutput"><span class="identifier">clone_ptr</span></code> has expected copy + constructor and assignment semantics, duplicating resources when copying. + Note that copy constructing or assigning a <code class="computeroutput"><span class="identifier">clone_ptr</span></code> + is a relatively expensive operation: + </p> +<p> +</p> +<pre class="programlisting"><span class="identifier">clone_ptr</span><span class="special"><</span><span class="identifier">Base</span><span class="special">></span> <span class="identifier">p1</span><span class="special">(</span><span class="keyword">new</span> <span class="identifier">Derived</span><span class="special">());</span> +<span class="comment">// ...</span> +<span class="identifier">clone_ptr</span><span class="special"><</span><span class="identifier">Base</span><span class="special">></span> <span class="identifier">p2</span> <span class="special">=</span> <span class="identifier">p1</span><span class="special">;</span> <span class="comment">// p2 and p1 each own their own pointer</span> +</pre> +<p> + </p> +<p> + <code class="computeroutput"><span class="identifier">clone_ptr</span></code> is code that you + might find in today's books on C++, except for the part marked as <code class="computeroutput"><span class="identifier">move</span> <span class="identifier">semantics</span></code>. + That part is implemented in terms of C++0x <code class="computeroutput"><span class="identifier">rvalue</span> + <span class="identifier">references</span></code>. You can find some good + introduction and tutorials on rvalue references in these papers: + </p> +<div class="itemizedlist"><ul class="itemizedlist" type="disc"> +<li class="listitem"> + <a href="http://www.artima.com/cppsource/rvalue.html" target="_top"><span class="emphasis"><em>A + Brief Introduction to Rvalue References</em></span></a> + </li> +<li class="listitem"> + <a href="http://blogs.msdn.com/vcblog/archive/2009/02/03/rvalue-references-c-0x-features-in-vc10-part-2.aspx" target="_top"><span class="emphasis"><em>Rvalue + References: C++0x Features in VC10, Part 2</em></span></a> + </li> +</ul></div> +<p> + When the source of the copy is known to be an <code class="computeroutput"><span class="identifier">rvalue</span></code> + (e.g.: a temporary object), one can avoid the potentially expensive <code class="computeroutput"><span class="identifier">clone</span><span class="special">()</span></code> + operation by pilfering source's pointer (no one will notice!). The move constructor + above does exactly that, leaving the rvalue in a default constructed state. + The move assignment operator simply does the same freeing old resources. + </p> +<p> + Now when code tries to copy an rvalue <code class="computeroutput"><span class="identifier">clone_ptr</span></code>, + or if that code explicitly gives permission to consider the source of the + copy an rvalue (using <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">move</span></code>), + the operation will execute much faster. + </p> +<p> +</p> +<pre class="programlisting"><span class="identifier">clone_ptr</span><span class="special"><</span><span class="identifier">Base</span><span class="special">></span> <span class="identifier">p1</span><span class="special">(</span><span class="keyword">new</span> <span class="identifier">Derived</span><span class="special">());</span> +<span class="comment">// ...</span> +<span class="identifier">clone_ptr</span><span class="special"><</span><span class="identifier">Base</span><span class="special">></span> <span class="identifier">p2</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">p1</span><span class="special">);</span> <span class="comment">// p2 now owns the pointer instead of p1</span> +<span class="identifier">p2</span> <span class="special">=</span> <span class="identifier">clone_ptr</span><span class="special"><</span><span class="identifier">Base</span><span class="special">>(</span><span class="keyword">new</span> <span class="identifier">Derived</span><span class="special">());</span> <span class="comment">// temporary is moved to p2</span> +<span class="special">}</span> +</pre> +<p> + </p> +</div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="move.implementing_movable_classes.copyable_and_movable_cpp03"></a><a class="link" href="implementing_movable_classes.html#move.implementing_movable_classes.copyable_and_movable_cpp03" title="Copyable and movable classes in portable syntax for both C++03 and C++0x compilers">Copyable + and movable classes in portable syntax for both C++03 and C++0x compilers</a> +</h3></div></div></div> +<p> + Many aspects of move semantics can be emulated for compilers not supporting + <code class="computeroutput"><span class="identifier">rvalue</span> <span class="identifier">references</span></code> + and <span class="bold"><strong>Boost.Move</strong></span> offers tools for that purpose. + With <span class="bold"><strong>Boost.Move</strong></span> we can write <code class="computeroutput"><span class="identifier">clone_ptr</span></code> so that it will work both in + compilers with rvalue references and those who conform to C++03. You just + need to follow these simple steps: + </p> +<div class="itemizedlist"><ul class="itemizedlist" type="disc"> +<li class="listitem"> + Put the following macro in the <span class="bold"><strong>private</strong></span> + section: <code class="computeroutput"><a class="link" href="../BOOST_COPYABLE_AND_MOVABLE.html" title="Macro BOOST_COPYABLE_AND_MOVABLE">BOOST_COPYABLE_AND_MOVABLE(classname)</a></code> + </li> +<li class="listitem"> + Left copy constructor as is. + </li> +<li class="listitem"> + Write a copy assignment taking the parameter as <code class="computeroutput"><a class="link" href="../BOOST_COPY_ASSIGN_REF.html" title="Macro BOOST_COPY_ASSIGN_REF">BOOST_COPY_ASSIGN_REF(classname)</a></code> + </li> +<li class="listitem"> + Write a move constructor and a move assignment taking the parameter as + <code class="computeroutput"><a class="link" href="../BOOST_RV_REF.html" title="Macro BOOST_RV_REF">BOOST_RV_REF(classname)</a></code> + </li> +</ul></div> +<p> + Let's see how are applied to <code class="computeroutput"><span class="identifier">clone_ptr</span></code>: + </p> +<p> +</p> +<pre class="programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> +<span class="keyword">class</span> <span class="identifier">clone_ptr</span> +<span class="special">{</span> + <span class="keyword">private</span><span class="special">:</span> + <span class="comment">// Mark this class copyable and movable</span> + <span class="identifier">BOOST_COPYABLE_AND_MOVABLE</span><span class="special">(</span><span class="identifier">clone_ptr</span><span class="special">)</span> + <span class="identifier">T</span><span class="special">*</span> <span class="identifier">ptr</span><span class="special">;</span> + + <span class="keyword">public</span><span class="special">:</span> + <span class="comment">// Construction</span> + <span class="keyword">explicit</span> <span class="identifier">clone_ptr</span><span class="special">(</span><span class="identifier">T</span><span class="special">*</span> <span class="identifier">p</span> <span class="special">=</span> <span class="number">0</span><span class="special">)</span> <span class="special">:</span> <span class="identifier">ptr</span><span class="special">(</span><span class="identifier">p</span><span class="special">)</span> <span class="special">{}</span> + + <span class="comment">// Destruction</span> + <span class="special">~</span><span class="identifier">clone_ptr</span><span class="special">()</span> <span class="special">{</span> <span class="keyword">delete</span> <span class="identifier">ptr</span><span class="special">;</span> <span class="special">}</span> + + <span class="identifier">clone_ptr</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">clone_ptr</span><span class="special">&</span> <span class="identifier">p</span><span class="special">)</span> <span class="comment">// Copy constructor (as usual)</span> + <span class="special">:</span> <span class="identifier">ptr</span><span class="special">(</span><span class="identifier">p</span><span class="special">.</span><span class="identifier">ptr</span> <span class="special">?</span> <span class="identifier">p</span><span class="special">.</span><span class="identifier">ptr</span><span class="special">-></span><span class="identifier">clone</span><span class="special">()</span> <span class="special">:</span> <span class="number">0</span><span class="special">)</span> <span class="special">{}</span> + + <span class="identifier">clone_ptr</span><span class="special">&</span> <span class="keyword">operator</span><span class="special">=(</span><span class="identifier">BOOST_COPY_ASSIGN_REF</span><span class="special">(</span><span class="identifier">clone_ptr</span><span class="special">)</span> <span class="identifier">p</span><span class="special">)</span> <span class="comment">// Copy assignment</span> + <span class="special">{</span> + <span class="keyword">if</span> <span class="special">(</span><span class="keyword">this</span> <span class="special">!=</span> <span class="special">&</span><span class="identifier">p</span><span class="special">){</span> + <span class="identifier">T</span> <span class="special">*</span><span class="identifier">tmp_p</span> <span class="special">=</span> <span class="identifier">p</span><span class="special">.</span><span class="identifier">ptr</span> <span class="special">?</span> <span class="identifier">p</span><span class="special">.</span><span class="identifier">ptr</span><span class="special">-></span><span class="identifier">clone</span><span class="special">()</span> <span class="special">:</span> <span class="number">0</span><span class="special">;</span> + <span class="keyword">delete</span> <span class="identifier">ptr</span><span class="special">;</span> + <span class="identifier">ptr</span> <span class="special">=</span> <span class="identifier">tmp_p</span><span class="special">;</span> + <span class="special">}</span> + <span class="keyword">return</span> <span class="special">*</span><span class="keyword">this</span><span class="special">;</span> + <span class="special">}</span> + + <span class="comment">//Move semantics...</span> + <span class="identifier">clone_ptr</span><span class="special">(</span><span class="identifier">BOOST_RV_REF</span><span class="special">(</span><span class="identifier">clone_ptr</span><span class="special">)</span> <span class="identifier">p</span><span class="special">)</span> <span class="comment">//Move constructor</span> + <span class="special">:</span> <span class="identifier">ptr</span><span class="special">(</span><span class="identifier">p</span><span class="special">.</span><span class="identifier">ptr</span><span class="special">)</span> <span class="special">{</span> <span class="identifier">p</span><span class="special">.</span><span class="identifier">ptr</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> <span class="special">}</span> + + <span class="identifier">clone_ptr</span><span class="special">&</span> <span class="keyword">operator</span><span class="special">=(</span><span class="identifier">BOOST_RV_REF</span><span class="special">(</span><span class="identifier">clone_ptr</span><span class="special">)</span> <span class="identifier">p</span><span class="special">)</span> <span class="comment">//Move assignment</span> + <span class="special">{</span> + <span class="keyword">if</span> <span class="special">(</span><span class="keyword">this</span> <span class="special">!=</span> <span class="special">&</span><span class="identifier">p</span><span class="special">){</span> + <span class="keyword">delete</span> <span class="identifier">ptr</span><span class="special">;</span> + <span class="identifier">ptr</span> <span class="special">=</span> <span class="identifier">p</span><span class="special">.</span><span class="identifier">ptr</span><span class="special">;</span> + <span class="identifier">p</span><span class="special">.</span><span class="identifier">ptr</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> + <span class="special">}</span> + <span class="keyword">return</span> <span class="special">*</span><span class="keyword">this</span><span class="special">;</span> + <span class="special">}</span> +<span class="special">};</span> +</pre> +<p> + </p> +</div> +<p> + <span class="bold"><strong>Question</strong></span>: What about types that don't own + resources? (E.g. <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">complex</span></code>?) + </p> +<p> + No work needs to be done in that case. The copy constructor is already optimal. + </p> +</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 © 2008-2010 Ion Gaztanaga<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> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="introduction.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="composition_inheritance.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/move/introduction.html b/doc/html/move/introduction.html new file mode 100755 index 0000000000..ff39f3a808 --- /dev/null +++ b/doc/html/move/introduction.html @@ -0,0 +1,100 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Introduction</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../move.html" title="Chapter 16. Boost.Move"> +<link rel="prev" href="../move.html" title="Chapter 16. Boost.Move"> +<link rel="next" href="implementing_movable_classes.html" title="Implementing copyable and movable classes"> +</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="../move.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="implementing_movable_classes.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="move.introduction"></a><a class="link" href="introduction.html" title="Introduction">Introduction</a> +</h2></div></div></div> +<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> + The first 3 chapters are the adapted from the article <a href="http://www.artima.com/cppsource/rvalue.html" target="_top"><span class="emphasis"><em>A + Brief Introduction to Rvalue References</em></span></a> by Howard E. Hinnant, + Bjarne Stroustrup, and Bronek Kozicki + </p></td></tr> +</table></div> +<p> + Copying can be expensive. For example, for vectors <code class="computeroutput"><span class="identifier">v2</span><span class="special">=</span><span class="identifier">v1</span></code> typically + involves a function call, a memory allocation, and a loop. This is of course + acceptable where we actually need two copies of a vector, but in many cases, + we don't: We often copy a <code class="computeroutput"><span class="identifier">vector</span></code> + from one place to another, just to proceed to overwrite the old copy. Consider: + </p> +<pre class="programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">void</span> <span class="identifier">swap</span><span class="special">(</span><span class="identifier">T</span><span class="special">&</span> <span class="identifier">a</span><span class="special">,</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">b</span><span class="special">)</span> +<span class="special">{</span> + <span class="identifier">T</span> <span class="identifier">tmp</span><span class="special">(</span><span class="identifier">a</span><span class="special">);</span> <span class="comment">// now we have two copies of a</span> + <span class="identifier">a</span> <span class="special">=</span> <span class="identifier">b</span><span class="special">;</span> <span class="comment">// now we have two copies of b</span> + <span class="identifier">b</span> <span class="special">=</span> <span class="identifier">tmp</span><span class="special">;</span> <span class="comment">// now we have two copies of tmp (aka a)</span> +<span class="special">}</span> +</pre> +<p> + But, we didn't want to have any copies of a or b, we just wanted to swap them. + Let's try again: + </p> +<pre class="programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">void</span> <span class="identifier">swap</span><span class="special">(</span><span class="identifier">T</span><span class="special">&</span> <span class="identifier">a</span><span class="special">,</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">b</span><span class="special">)</span> +<span class="special">{</span> + <span class="identifier">T</span> <span class="identifier">tmp</span><span class="special">(::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">a</span><span class="special">));</span> + <span class="identifier">a</span> <span class="special">=</span> <span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">b</span><span class="special">);</span> + <span class="identifier">b</span> <span class="special">=</span> <span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">tmp</span><span class="special">);</span> +<span class="special">}</span> +</pre> +<p> + This <code class="computeroutput"><span class="identifier">move</span><span class="special">()</span></code> + gives its target the value of its argument, but is not obliged to preserve + the value of its source. So, for a <code class="computeroutput"><span class="identifier">vector</span></code>, + <code class="computeroutput"><span class="identifier">move</span><span class="special">()</span></code> + could reasonably be expected to leave its argument as a zero-capacity vector + to avoid having to copy all the elements. In other words, <span class="bold"><strong>move + is a potentially destructive copy</strong></span>. + </p> +<p> + In this particular case, we could have optimized swap by a specialization. + However, we can't specialize every function that copies a large object just + before it deletes or overwrites it. That would be unmanageable. + </p> +<p> + In C++0x, move semantics are implemented with the introduction of rvalue references. + They allow us to implement <code class="computeroutput"><span class="identifier">move</span><span class="special">()</span></code> without verbosity or runtime overhead. <span class="bold"><strong>Boost.Move</strong></span> is a library that offers tools to implement + those move semantics not only in compilers with <code class="computeroutput"><span class="identifier">rvalue</span> + <span class="identifier">references</span></code> but also in compilers + conforming to C++03. + </p> +</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 © 2008-2010 Ion Gaztanaga<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> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="../move.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="implementing_movable_classes.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/move/movable_only_classes.html b/doc/html/move/movable_only_classes.html new file mode 100755 index 0000000000..42e79f5d40 --- /dev/null +++ b/doc/html/move/movable_only_classes.html @@ -0,0 +1,131 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Movable but Non-Copyable Types</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../move.html" title="Chapter 16. Boost.Move"> +<link rel="prev" href="composition_inheritance.html" title="Composition or inheritance"> +<link rel="next" href="move_and_containers.html" title="Containers and move semantics"> +</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="composition_inheritance.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="move_and_containers.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="move.movable_only_classes"></a><a class="link" href="movable_only_classes.html" title="Movable but Non-Copyable Types">Movable but Non-Copyable Types</a> +</h2></div></div></div> +<p> + Some types are not amenable to copy semantics but can still be made movable. + For example: + </p> +<div class="itemizedlist"><ul class="itemizedlist" type="disc"> +<li class="listitem"> + <code class="computeroutput"><span class="identifier">unique_ptr</span></code> (non-shared, + non-copyable ownership) + </li> +<li class="listitem"> + A type representing a thread of execution + </li> +<li class="listitem"> + A type representing a file descriptor + </li> +</ul></div> +<p> + By making such types movable (though still non-copyable) their utility is tremendously + increased. Movable but non-copyable types can be returned by value from factory + functions: + </p> +<pre class="programlisting"><span class="identifier">file_descriptor</span> <span class="identifier">create_file</span><span class="special">(/*</span> <span class="special">...</span> <span class="special">*/);</span> +<span class="comment">//...</span> +<span class="identifier">file_descriptor</span> <span class="identifier">data_file</span><span class="special">;</span> +<span class="comment">//...</span> +<span class="identifier">data_file</span> <span class="special">=</span> <span class="identifier">create_file</span><span class="special">(/*</span> <span class="special">...</span> <span class="special">*/);</span> <span class="comment">// No copies!</span> +</pre> +<p> + In the above example, the underlying file handle is passed from object to object, + as long as the source <code class="computeroutput"><span class="identifier">file_descriptor</span></code> + is an rvalue. At all times, there is still only one underlying file handle, + and only one <code class="computeroutput"><span class="identifier">file_descriptor</span></code> + owns it at a time. + </p> +<p> + To write a movable but not copyable type in portable syntax, you need to follow + these simple steps: + </p> +<div class="itemizedlist"><ul class="itemizedlist" type="disc"> +<li class="listitem"> + Put the following macro in the <span class="bold"><strong>private</strong></span> + section: <code class="computeroutput"><a class="link" href="../BOOST_MOVABLE_BUT_NOT_COPYABLE.html" title="Macro BOOST_MOVABLE_BUT_NOT_COPYABLE">BOOST_MOVABLE_BUT_NOT_COPYABLE(classname)</a></code> + </li> +<li class="listitem"> + Write a move constructor and a move assignment taking the parameter as + <code class="computeroutput"><a class="link" href="../BOOST_RV_REF.html" title="Macro BOOST_RV_REF">BOOST_RV_REF(classname)</a></code> + </li> +</ul></div> +<p> + Here's the definition of <code class="computeroutput"><span class="identifier">file</span> <span class="identifier">descriptor</span></code> using portable syntax: + </p> +<p> +</p> +<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">move</span><span class="special">/</span><span class="identifier">move</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">stdexcept</span><span class="special">></span> + +<span class="keyword">class</span> <span class="identifier">file_descriptor</span> +<span class="special">{</span> + <span class="keyword">int</span> <span class="identifier">os_descr_</span><span class="special">;</span> + + <span class="keyword">private</span><span class="special">:</span> + <span class="identifier">BOOST_MOVABLE_BUT_NOT_COPYABLE</span><span class="special">(</span><span class="identifier">file_descriptor</span><span class="special">)</span> + + <span class="keyword">public</span><span class="special">:</span> + <span class="keyword">explicit</span> <span class="identifier">file_descriptor</span><span class="special">(</span><span class="keyword">const</span> <span class="keyword">char</span> <span class="special">*</span><span class="identifier">filename</span> <span class="special">=</span> <span class="number">0</span><span class="special">)</span> <span class="comment">//Constructor</span> + <span class="special">:</span> <span class="identifier">os_descr_</span><span class="special">(</span><span class="identifier">filename</span> <span class="special">?</span> <span class="identifier">operating_system_open_file</span><span class="special">(</span><span class="identifier">filename</span><span class="special">)</span> <span class="special">:</span> <span class="number">0</span><span class="special">)</span> + <span class="special">{</span> <span class="keyword">if</span><span class="special">(!</span><span class="identifier">os_descr_</span><span class="special">)</span> <span class="keyword">throw</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">runtime_error</span><span class="special">(</span><span class="string">"file not found"</span><span class="special">);</span> <span class="special">}</span> + + <span class="special">~</span><span class="identifier">file_descriptor</span><span class="special">()</span> <span class="comment">//Destructor</span> + <span class="special">{</span> <span class="keyword">if</span><span class="special">(!</span><span class="identifier">os_descr_</span><span class="special">)</span> <span class="identifier">operating_system_close_file</span><span class="special">(</span><span class="identifier">os_descr_</span><span class="special">);</span> <span class="special">}</span> + + <span class="identifier">file_descriptor</span><span class="special">(</span><span class="identifier">BOOST_RV_REF</span><span class="special">(</span><span class="identifier">file_descriptor</span><span class="special">)</span> <span class="identifier">x</span><span class="special">)</span> <span class="comment">// Move ctor</span> + <span class="special">:</span> <span class="identifier">os_descr_</span><span class="special">(</span><span class="identifier">x</span><span class="special">.</span><span class="identifier">os_descr_</span><span class="special">)</span> + <span class="special">{</span> <span class="identifier">x</span><span class="special">.</span><span class="identifier">os_descr_</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> <span class="special">}</span> + + <span class="identifier">file_descriptor</span><span class="special">&</span> <span class="keyword">operator</span><span class="special">=(</span><span class="identifier">BOOST_RV_REF</span><span class="special">(</span><span class="identifier">file_descriptor</span><span class="special">)</span> <span class="identifier">x</span><span class="special">)</span> <span class="comment">// Move assign</span> + <span class="special">{</span> + <span class="keyword">if</span><span class="special">(!</span><span class="identifier">os_descr_</span><span class="special">)</span> <span class="identifier">operating_system_close_file</span><span class="special">(</span><span class="identifier">os_descr_</span><span class="special">);</span> + <span class="identifier">os_descr_</span> <span class="special">=</span> <span class="identifier">x</span><span class="special">.</span><span class="identifier">os_descr_</span><span class="special">;</span> + <span class="identifier">x</span><span class="special">.</span><span class="identifier">os_descr_</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> + <span class="keyword">return</span> <span class="special">*</span><span class="keyword">this</span><span class="special">;</span> + <span class="special">}</span> + + <span class="keyword">bool</span> <span class="identifier">empty</span><span class="special">()</span> <span class="keyword">const</span> <span class="special">{</span> <span class="keyword">return</span> <span class="identifier">os_descr_</span> <span class="special">==</span> <span class="number">0</span><span class="special">;</span> <span class="special">}</span> +<span class="special">};</span> +</pre> +<p> + </p> +</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 © 2008-2010 Ion Gaztanaga<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> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="composition_inheritance.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="move_and_containers.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/move/move_algorithms.html b/doc/html/move/move_algorithms.html new file mode 100755 index 0000000000..68625956a8 --- /dev/null +++ b/doc/html/move/move_algorithms.html @@ -0,0 +1,95 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Move algorithms</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../move.html" title="Chapter 16. Boost.Move"> +<link rel="prev" href="move_inserters.html" title="Move inserters"> +<link rel="next" href="emulation_limitations.html" title="Emulation limitations"> +</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="move_inserters.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="emulation_limitations.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="move.move_algorithms"></a><a class="link" href="move_algorithms.html" title="Move algorithms">Move algorithms</a> +</h2></div></div></div> +<p> + The standard library offers several copy-based algorithms. Some of them, like + <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">copy</span></code> or <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">uninitialized_copy</span></code> + are basic building blocks for containers and other data structures. This library + offers move-based functions for those purposes: + </p> +<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <span class="identifier">I</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">O</span><span class="special">></span> <span class="identifier">O</span> <span class="identifier">move</span><span class="special">(</span><span class="identifier">I</span><span class="special">,</span> <span class="identifier">I</span><span class="special">,</span> <span class="identifier">O</span><span class="special">);</span> +<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <span class="identifier">I</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">O</span><span class="special">></span> <span class="identifier">O</span> <span class="identifier">move_backward</span><span class="special">(</span><span class="identifier">I</span><span class="special">,</span> <span class="identifier">I</span><span class="special">,</span> <span class="identifier">O</span><span class="special">);</span> +<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <span class="identifier">I</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">F</span><span class="special">></span> <span class="identifier">F</span> <span class="identifier">uninitialized_move</span><span class="special">(</span><span class="identifier">I</span><span class="special">,</span> <span class="identifier">I</span><span class="special">,</span> <span class="identifier">F</span><span class="special">);</span> +<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <span class="identifier">I</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">F</span><span class="special">></span> <span class="identifier">F</span> <span class="identifier">uninitialized_copy_or_move</span><span class="special">(</span><span class="identifier">I</span><span class="special">,</span> <span class="identifier">I</span><span class="special">,</span> <span class="identifier">F</span><span class="special">);</span> +</pre> +<p> + The first 3 are move variations of their equivalent copy algorithms, but copy + assignment and copy construction are replaced with move assignment and construction. + The last one has the same behaviour as <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">uninitialized_copy</span></code> + but since several standand library implementations don't play very well with + <code class="computeroutput"><span class="identifier">move_iterator</span></code>s, this version + is a portable version for those willing to use move iterators. + </p> +<p> +</p> +<pre class="programlisting"><span class="preprocessor">#include</span> <span class="string">"movable.hpp"</span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">cassert</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">aligned_storage</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> + +<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> +<span class="special">{</span> + <span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">ArraySize</span> <span class="special">=</span> <span class="number">10</span><span class="special">;</span> + <span class="identifier">movable</span> <span class="identifier">movable_array</span><span class="special">[</span><span class="identifier">ArraySize</span><span class="special">];</span> + <span class="identifier">movable</span> <span class="identifier">movable_array2</span><span class="special">[</span><span class="identifier">ArraySize</span><span class="special">];</span> + <span class="comment">//move</span> + <span class="identifier">boost</span><span class="special">::</span><span class="identifier">move</span><span class="special">(&</span><span class="identifier">movable_array2</span><span class="special">[</span><span class="number">0</span><span class="special">],</span> <span class="special">&</span><span class="identifier">movable_array2</span><span class="special">[</span><span class="identifier">ArraySize</span><span class="special">],</span> <span class="special">&</span><span class="identifier">movable_array</span><span class="special">[</span><span class="number">0</span><span class="special">]);</span> + <span class="identifier">assert</span><span class="special">(</span><span class="identifier">movable_array2</span><span class="special">[</span><span class="number">0</span><span class="special">].</span><span class="identifier">moved</span><span class="special">());</span> + <span class="identifier">assert</span><span class="special">(!</span><span class="identifier">movable_array</span><span class="special">[</span><span class="number">0</span><span class="special">].</span><span class="identifier">moved</span><span class="special">());</span> + + <span class="comment">//move backward</span> + <span class="identifier">boost</span><span class="special">::</span><span class="identifier">move_backward</span><span class="special">(&</span><span class="identifier">movable_array</span><span class="special">[</span><span class="number">0</span><span class="special">],</span> <span class="special">&</span><span class="identifier">movable_array</span><span class="special">[</span><span class="identifier">ArraySize</span><span class="special">],</span> <span class="special">&</span><span class="identifier">movable_array2</span><span class="special">[</span><span class="identifier">ArraySize</span><span class="special">]);</span> + <span class="identifier">assert</span><span class="special">(</span><span class="identifier">movable_array</span><span class="special">[</span><span class="number">0</span><span class="special">].</span><span class="identifier">moved</span><span class="special">());</span> + <span class="identifier">assert</span><span class="special">(!</span><span class="identifier">movable_array2</span><span class="special">[</span><span class="number">0</span><span class="special">].</span><span class="identifier">moved</span><span class="special">());</span> + + <span class="comment">//uninitialized_move</span> + <span class="identifier">boost</span><span class="special">::</span><span class="identifier">aligned_storage</span><span class="special"><</span> <span class="keyword">sizeof</span><span class="special">(</span><span class="identifier">movable</span><span class="special">)*</span><span class="identifier">ArraySize</span> + <span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">alignment_of</span><span class="special"><</span><span class="identifier">movable</span><span class="special">>::</span><span class="identifier">value</span><span class="special">>::</span><span class="identifier">type</span> <span class="identifier">storage</span><span class="special">;</span> + <span class="identifier">movable</span> <span class="special">*</span><span class="identifier">raw_movable</span> <span class="special">=</span> <span class="keyword">static_cast</span><span class="special"><</span><span class="identifier">movable</span><span class="special">*>(</span><span class="keyword">static_cast</span><span class="special"><</span><span class="keyword">void</span><span class="special">*>(&</span><span class="identifier">storage</span><span class="special">));</span> + <span class="identifier">boost</span><span class="special">::</span><span class="identifier">uninitialized_move</span><span class="special">(&</span><span class="identifier">movable_array2</span><span class="special">[</span><span class="number">0</span><span class="special">],</span> <span class="special">&</span><span class="identifier">movable_array2</span><span class="special">[</span><span class="identifier">ArraySize</span><span class="special">],</span> <span class="identifier">raw_movable</span><span class="special">);</span> + <span class="identifier">assert</span><span class="special">(</span><span class="identifier">movable_array2</span><span class="special">[</span><span class="number">0</span><span class="special">].</span><span class="identifier">moved</span><span class="special">());</span> + <span class="identifier">assert</span><span class="special">(!</span><span class="identifier">raw_movable</span><span class="special">[</span><span class="number">0</span><span class="special">].</span><span class="identifier">moved</span><span class="special">());</span> + <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> +<span class="special">}</span> +</pre> +<p> + </p> +</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 © 2008-2010 Ion Gaztanaga<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> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="move_inserters.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="emulation_limitations.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/move/move_and_containers.html b/doc/html/move/move_and_containers.html new file mode 100755 index 0000000000..c32c9cebca --- /dev/null +++ b/doc/html/move/move_and_containers.html @@ -0,0 +1,84 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Containers and move semantics</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../move.html" title="Chapter 16. Boost.Move"> +<link rel="prev" href="movable_only_classes.html" title="Movable but Non-Copyable Types"> +<link rel="next" href="construct_forwarding.html" title="Constructor Forwarding"> +</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="movable_only_classes.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="construct_forwarding.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="move.move_and_containers"></a><a class="link" href="move_and_containers.html" title="Containers and move semantics">Containers and move semantics</a> +</h2></div></div></div> +<p> + Movable but non-copyable types can be safely inserted into containers and movable + and copyable types are more efficiently handled if those containers internally + use move semantics instead of copy semantics. If the container needs to "change + the location" of an element internally (e.g. vector reallocation) it will + move the element instead of copying it. <span class="bold"><strong>Boost.Container</strong></span> + containers are move-aware so you can write the following: + </p> +<p> +</p> +<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">container</span><span class="special">/</span><span class="identifier">vector</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">cassert</span><span class="special">></span> + +<span class="comment">//Remember: 'file_descriptor' is NOT copyable, but it</span> +<span class="comment">//can be returned from functions thanks to move semantics</span> +<span class="identifier">file_descriptor</span> <span class="identifier">create_file_descriptor</span><span class="special">(</span><span class="keyword">const</span> <span class="keyword">char</span> <span class="special">*</span><span class="identifier">filename</span><span class="special">)</span> +<span class="special">{</span> <span class="keyword">return</span> <span class="identifier">file_descriptor</span><span class="special">(</span><span class="identifier">filename</span><span class="special">);</span> <span class="special">}</span> + +<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> +<span class="special">{</span> + <span class="comment">//Open a file obtaining its descriptor, the temporary</span> + <span class="comment">//returned from 'create_file_descriptor' is moved to 'fd'.</span> + <span class="identifier">file_descriptor</span> <span class="identifier">fd</span> <span class="special">=</span> <span class="identifier">create_file_descriptor</span><span class="special">(</span><span class="string">"filename"</span><span class="special">);</span> + <span class="identifier">assert</span><span class="special">(!</span><span class="identifier">fd</span><span class="special">.</span><span class="identifier">empty</span><span class="special">());</span> + + <span class="comment">//Now move fd into a vector</span> + <span class="identifier">boost</span><span class="special">::</span><span class="identifier">container</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span><span class="identifier">file_descriptor</span><span class="special">></span> <span class="identifier">v</span><span class="special">;</span> + <span class="identifier">v</span><span class="special">.</span><span class="identifier">push_back</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">fd</span><span class="special">));</span> + + <span class="comment">//Check ownership has been transferred</span> + <span class="identifier">assert</span><span class="special">(</span><span class="identifier">fd</span><span class="special">.</span><span class="identifier">empty</span><span class="special">());</span> + <span class="identifier">assert</span><span class="special">(!</span><span class="identifier">v</span><span class="special">[</span><span class="number">0</span><span class="special">].</span><span class="identifier">empty</span><span class="special">());</span> + + <span class="comment">//Compilation error if uncommented since file_descriptor is not copyable</span> + <span class="comment">//and vector copy construction requires value_type's copy constructor:</span> + <span class="comment">//boost::container::vector<file_descriptor> v2(v);</span> + <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> +<span class="special">}</span> +</pre> +<p> + </p> +</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 © 2008-2010 Ion Gaztanaga<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> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="movable_only_classes.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="construct_forwarding.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/move/move_inserters.html b/doc/html/move/move_inserters.html new file mode 100755 index 0000000000..e954db76ff --- /dev/null +++ b/doc/html/move/move_inserters.html @@ -0,0 +1,133 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Move inserters</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../move.html" title="Chapter 16. Boost.Move"> +<link rel="prev" href="move_iterator.html" title="Move iterators"> +<link rel="next" href="move_algorithms.html" title="Move algorithms"> +</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="move_iterator.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="move_algorithms.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="move.move_inserters"></a><a class="link" href="move_inserters.html" title="Move inserters">Move inserters</a> +</h2></div></div></div> +<p> + Similar to standard insert iterators, it's possible to deal with move insertion + in the same way as writing into an array. A special kind of iterator adaptors, + called move insert iterators, are provided with this library. With regular + iterator classes, + </p> +<pre class="programlisting"><span class="keyword">while</span> <span class="special">(</span><span class="identifier">first</span> <span class="special">!=</span> <span class="identifier">last</span><span class="special">)</span> <span class="special">*</span><span class="identifier">result</span><span class="special">++</span> <span class="special">=</span> <span class="special">*</span><span class="identifier">first</span><span class="special">++;</span> +</pre> +<p> + causes a range [first,last) to be copied into a range starting with result. + The same code with result being an move insert iterator will move insert corresponding + elements into the container. This device allows all of the copying algorithms + in the library to work in the move insert mode instead of the regular overwrite + mode. This library offers 3 move insert iterators and their helper functions: + </p> +<pre class="programlisting"><span class="comment">// Note: C models Container</span> +<span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">C</span><span class="special">></span> +<span class="keyword">class</span> <span class="identifier">back_move_insert_iterator</span><span class="special">;</span> + +<span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">C</span><span class="special">></span> +<span class="identifier">back_move_insert_iterator</span><span class="special"><</span><span class="identifier">C</span><span class="special">></span> <span class="identifier">back_move_inserter</span><span class="special">(</span><span class="identifier">C</span><span class="special">&</span> <span class="identifier">x</span><span class="special">);</span> + +<span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">C</span><span class="special">></span> +<span class="keyword">class</span> <span class="identifier">front_move_insert_iterator</span><span class="special">;</span> + +<span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">C</span><span class="special">></span> +<span class="identifier">front_move_insert_iterator</span><span class="special"><</span><span class="identifier">C</span><span class="special">></span> <span class="identifier">front_move_inserter</span><span class="special">(</span><span class="identifier">C</span><span class="special">&</span> <span class="identifier">x</span><span class="special">);</span> + +<span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">C</span><span class="special">></span> +<span class="keyword">class</span> <span class="identifier">move_insert_iterator</span><span class="special">;</span> + +<span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">C</span><span class="special">></span> +<span class="identifier">move_insert_iterator</span><span class="special"><</span><span class="identifier">C</span><span class="special">></span> <span class="identifier">move_inserter</span><span class="special">(</span><span class="identifier">C</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">C</span><span class="special">::</span><span class="identifier">iterator</span> <span class="identifier">it</span><span class="special">);</span> +</pre> +<p> + A move insert iterator is constructed from a container and possibly one of + its iterators pointing to where insertion takes place if it is neither at the + beginning nor at the end of the container. Insert iterators satisfy the requirements + of output iterators. <code class="computeroutput"><span class="keyword">operator</span><span class="special">*</span></code> returns the move insert iterator itself. The + assignment <code class="computeroutput"><span class="keyword">operator</span><span class="special">=(</span><span class="identifier">T</span><span class="special">&</span> <span class="identifier">x</span><span class="special">)</span></code> is defined on insert iterators to allow writing + into them, it inserts x right before where the insert iterator is pointing. + In other words, an <code class="computeroutput"><span class="identifier">insert</span> <span class="identifier">iterator</span></code> is like a cursor pointing into the + container where the insertion takes place. <code class="computeroutput"><span class="identifier">back_move_iterator</span></code> + move inserts elements at the end of a container, <code class="computeroutput"><span class="identifier">front_insert_iterator</span></code> + move inserts elements at the beginning of a container, and <code class="computeroutput"><span class="identifier">move_insert_iterator</span></code> + move inserts elements where the iterator points to in a container. <code class="computeroutput"><span class="identifier">back_move_inserter</span></code>, <code class="computeroutput"><span class="identifier">front_move_inserter</span></code>, + and <code class="computeroutput"><span class="identifier">move_inserter</span></code> are three + functions making the insert iterators out of a container. Here's an example + of how to use them: + </p> +<p> +</p> +<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">container</span><span class="special">/</span><span class="identifier">list</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="string">"movable.hpp"</span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">cassert</span><span class="special">></span> + +<span class="keyword">using</span> <span class="keyword">namespace</span> <span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">container</span><span class="special">;</span> + +<span class="keyword">typedef</span> <span class="identifier">list</span><span class="special"><</span><span class="identifier">movable</span><span class="special">></span> <span class="identifier">list_t</span><span class="special">;</span> +<span class="keyword">typedef</span> <span class="identifier">list_t</span><span class="special">::</span><span class="identifier">iterator</span> <span class="identifier">l_iterator</span><span class="special">;</span> + +<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">MoveInsertIterator</span><span class="special">></span> +<span class="keyword">void</span> <span class="identifier">test_move_inserter</span><span class="special">(</span><span class="identifier">list_t</span> <span class="special">&</span><span class="identifier">l2</span><span class="special">,</span> <span class="identifier">MoveInsertIterator</span> <span class="identifier">mit</span><span class="special">)</span> +<span class="special">{</span> + <span class="comment">//Create a list with 10 default constructed objects</span> + <span class="identifier">list</span><span class="special"><</span><span class="identifier">movable</span><span class="special">></span> <span class="identifier">l</span><span class="special">(</span><span class="number">10</span><span class="special">);</span> + <span class="identifier">assert</span><span class="special">(!</span><span class="identifier">l</span><span class="special">.</span><span class="identifier">begin</span><span class="special">()-></span><span class="identifier">moved</span><span class="special">());</span> + <span class="identifier">l2</span><span class="special">.</span><span class="identifier">clear</span><span class="special">();</span> + + <span class="comment">//Move construct</span> + <span class="keyword">for</span><span class="special">(</span><span class="identifier">l_iterator</span> <span class="identifier">itbeg</span> <span class="special">=</span> <span class="identifier">l</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(),</span> <span class="identifier">itend</span> <span class="special">=</span> <span class="identifier">l</span><span class="special">.</span><span class="identifier">end</span><span class="special">();</span> <span class="identifier">itbeg</span> <span class="special">!=</span> <span class="identifier">itend</span><span class="special">;</span> <span class="special">++</span><span class="identifier">itbeg</span><span class="special">){</span> + <span class="special">*</span><span class="identifier">mit</span> <span class="special">=</span> <span class="special">*</span><span class="identifier">itbeg</span><span class="special">;</span> + <span class="special">}</span> + <span class="comment">//Check size and status</span> + <span class="identifier">assert</span><span class="special">(</span><span class="identifier">l2</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span> <span class="special">==</span> <span class="identifier">l</span><span class="special">.</span><span class="identifier">size</span><span class="special">());</span> + <span class="identifier">assert</span><span class="special">(</span><span class="identifier">l</span><span class="special">.</span><span class="identifier">begin</span><span class="special">()-></span><span class="identifier">moved</span><span class="special">());</span> + <span class="identifier">assert</span><span class="special">(!</span><span class="identifier">l2</span><span class="special">.</span><span class="identifier">begin</span><span class="special">()-></span><span class="identifier">moved</span><span class="special">());</span> +<span class="special">}</span> + +<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> +<span class="special">{</span> + <span class="identifier">list_t</span> <span class="identifier">l2</span><span class="special">;</span> + <span class="identifier">test_move_inserter</span><span class="special">(</span><span class="identifier">l2</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">back_move_inserter</span><span class="special">(</span><span class="identifier">l2</span><span class="special">));</span> + <span class="identifier">test_move_inserter</span><span class="special">(</span><span class="identifier">l2</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">front_move_inserter</span><span class="special">(</span><span class="identifier">l2</span><span class="special">));</span> + <span class="identifier">test_move_inserter</span><span class="special">(</span><span class="identifier">l2</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">move_inserter</span><span class="special">(</span><span class="identifier">l2</span><span class="special">,</span> <span class="identifier">l2</span><span class="special">.</span><span class="identifier">end</span><span class="special">()));</span> + <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> +<span class="special">}</span> +</pre> +<p> + </p> +</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 © 2008-2010 Ion Gaztanaga<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> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="move_iterator.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="move_algorithms.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/move/move_iterator.html b/doc/html/move/move_iterator.html new file mode 100755 index 0000000000..2802cb5053 --- /dev/null +++ b/doc/html/move/move_iterator.html @@ -0,0 +1,134 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Move iterators</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../move.html" title="Chapter 16. Boost.Move"> +<link rel="prev" href="construct_forwarding.html" title="Constructor Forwarding"> +<link rel="next" href="move_inserters.html" title="Move inserters"> +</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="construct_forwarding.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="move_inserters.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="move.move_iterator"></a><a class="link" href="move_iterator.html" title="Move iterators">Move iterators</a> +</h2></div></div></div> +<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">Iterator</span><span class="special">></span> +<span class="keyword">class</span> <span class="identifier">move_iterator</span><span class="special">;</span> + +<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">It</span><span class="special">></span> +<span class="identifier">move_iterator</span><span class="special"><</span><span class="identifier">It</span><span class="special">></span> <span class="identifier">make_move_iterator</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">It</span> <span class="special">&</span><span class="identifier">it</span><span class="special">);</span> +</pre> +<p> + <code class="computeroutput"><a class="link" href="../boost/move_iterator.html" title="Class template move_iterator">move_iterator</a></code> is an iterator + adaptor with the same behavior as the underlying iterator except that its dereference + operator implicitly converts the value returned by the underlying iterator's + dereference operator to an rvalue reference: <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">move</span><span class="special">(*</span><span class="identifier">underlying_iterator</span><span class="special">)</span></code> + It is a read-once iterator, but can have up to random access traversal characteristics. + </p> +<p> + <code class="computeroutput"><span class="identifier">move_iterator</span></code> is very useful + because some generic algorithms and container insertion functions can be called + with move iterators to replace copying with moving. For example: + </p> +<p> +</p> +<pre class="programlisting"><span class="comment">//header file "movable.hpp"</span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">move</span><span class="special">/</span><span class="identifier">move</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> + +<span class="comment">//A movable class</span> +<span class="keyword">class</span> <span class="identifier">movable</span> +<span class="special">{</span> + <span class="identifier">BOOST_MOVABLE_BUT_NOT_COPYABLE</span><span class="special">(</span><span class="identifier">movable</span><span class="special">)</span> + <span class="keyword">int</span> <span class="identifier">value_</span><span class="special">;</span> + + <span class="keyword">public</span><span class="special">:</span> + <span class="identifier">movable</span><span class="special">()</span> <span class="special">:</span> <span class="identifier">value_</span><span class="special">(</span><span class="number">1</span><span class="special">){}</span> + + <span class="comment">//Move constructor and assignment</span> + <span class="identifier">movable</span><span class="special">(</span><span class="identifier">BOOST_RV_REF</span><span class="special">(</span><span class="identifier">movable</span><span class="special">)</span> <span class="identifier">m</span><span class="special">)</span> + <span class="special">{</span> <span class="identifier">value_</span> <span class="special">=</span> <span class="identifier">m</span><span class="special">.</span><span class="identifier">value_</span><span class="special">;</span> <span class="identifier">m</span><span class="special">.</span><span class="identifier">value_</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> <span class="special">}</span> + + <span class="identifier">movable</span> <span class="special">&</span> <span class="keyword">operator</span><span class="special">=(</span><span class="identifier">BOOST_RV_REF</span><span class="special">(</span><span class="identifier">movable</span><span class="special">)</span> <span class="identifier">m</span><span class="special">)</span> + <span class="special">{</span> <span class="identifier">value_</span> <span class="special">=</span> <span class="identifier">m</span><span class="special">.</span><span class="identifier">value_</span><span class="special">;</span> <span class="identifier">m</span><span class="special">.</span><span class="identifier">value_</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> <span class="keyword">return</span> <span class="special">*</span><span class="keyword">this</span><span class="special">;</span> <span class="special">}</span> + + <span class="keyword">bool</span> <span class="identifier">moved</span><span class="special">()</span> <span class="keyword">const</span> <span class="comment">//Observer</span> + <span class="special">{</span> <span class="keyword">return</span> <span class="identifier">value_</span> <span class="special">==</span> <span class="number">0</span><span class="special">;</span> <span class="special">}</span> +<span class="special">};</span> + +<span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">{</span> + +<span class="keyword">template</span><span class="special"><></span> +<span class="keyword">struct</span> <span class="identifier">has_nothrow_move</span><span class="special"><</span><span class="identifier">movable</span><span class="special">></span> +<span class="special">{</span> + <span class="keyword">static</span> <span class="keyword">const</span> <span class="keyword">bool</span> <span class="identifier">value</span> <span class="special">=</span> <span class="keyword">true</span><span class="special">;</span> +<span class="special">};</span> + +<span class="special">}</span> <span class="comment">//namespace boost{</span> +</pre> +<p> + </p> +<p> + <code class="computeroutput"><span class="identifier">movable</span></code> objects can be moved + from one container to another using move iterators and insertion and assignment + operations.w + </p> +<p> +</p> +<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">container</span><span class="special">/</span><span class="identifier">vector</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> +<span class="preprocessor">#include</span> <span class="string">"movable.hpp"</span> +<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">cassert</span><span class="special">></span> + +<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> +<span class="special">{</span> + <span class="keyword">using</span> <span class="keyword">namespace</span> <span class="special">::</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">container</span><span class="special">;</span> + + <span class="comment">//Create a vector with 10 default constructed objects</span> + <span class="identifier">vector</span><span class="special"><</span><span class="identifier">movable</span><span class="special">></span> <span class="identifier">v</span><span class="special">(</span><span class="number">10</span><span class="special">);</span> + <span class="identifier">assert</span><span class="special">(!</span><span class="identifier">v</span><span class="special">[</span><span class="number">0</span><span class="special">].</span><span class="identifier">moved</span><span class="special">());</span> + + <span class="comment">//Move construct all elements in v into v2</span> + <span class="identifier">vector</span><span class="special"><</span><span class="identifier">movable</span><span class="special">></span> <span class="identifier">v2</span><span class="special">(</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">make_move_iterator</span><span class="special">(</span><span class="identifier">v</span><span class="special">.</span><span class="identifier">begin</span><span class="special">())</span> + <span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">make_move_iterator</span><span class="special">(</span><span class="identifier">v</span><span class="special">.</span><span class="identifier">end</span><span class="special">()));</span> + <span class="identifier">assert</span><span class="special">(</span><span class="identifier">v</span><span class="special">[</span><span class="number">0</span><span class="special">].</span><span class="identifier">moved</span><span class="special">());</span> + <span class="identifier">assert</span><span class="special">(!</span><span class="identifier">v2</span><span class="special">[</span><span class="number">0</span><span class="special">].</span><span class="identifier">moved</span><span class="special">());</span> + + <span class="comment">//Now move assign all elements from in v2 back into v</span> + <span class="identifier">v</span><span class="special">.</span><span class="identifier">assign</span><span class="special">(</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">make_move_iterator</span><span class="special">(</span><span class="identifier">v2</span><span class="special">.</span><span class="identifier">begin</span><span class="special">())</span> + <span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">make_move_iterator</span><span class="special">(</span><span class="identifier">v2</span><span class="special">.</span><span class="identifier">end</span><span class="special">()));</span> + <span class="identifier">assert</span><span class="special">(</span><span class="identifier">v2</span><span class="special">[</span><span class="number">0</span><span class="special">].</span><span class="identifier">moved</span><span class="special">());</span> + <span class="identifier">assert</span><span class="special">(!</span><span class="identifier">v</span><span class="special">[</span><span class="number">0</span><span class="special">].</span><span class="identifier">moved</span><span class="special">());</span> + + <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> +<span class="special">}</span> +</pre> +<p> + </p> +</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 © 2008-2010 Ion Gaztanaga<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> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="construct_forwarding.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="move_inserters.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/move/reference.html b/doc/html/move/reference.html new file mode 100755 index 0000000000..1a5155fe16 --- /dev/null +++ b/doc/html/move/reference.html @@ -0,0 +1,78 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Reference</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../move.html" title="Chapter 16. Boost.Move"> +<link rel="prev" href="release_notes.html" title="Release Notes"> +<link rel="next" href="../boost/has_nothrow_move.html" title="Struct template has_nothrow_move"> +</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="release_notes.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="../boost/has_nothrow_move.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="move.reference"></a>Reference</h2></div></div></div> +<div class="toc"><dl><dt><span class="section"><a href="reference.html#header.boost.move.move_hpp">Header <boost/move/move.hpp></a></span></dt></dl></div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="header.boost.move.move_hpp"></a>Header <<a href="../../../boost/move/move.hpp" target="_top">boost/move/move.hpp</a>></h3></div></div></div> +<pre class="synopsis"> + +<a class="link" href="../BOOST_MOVABLE_BUT_NOT_COPYABLE.html" title="Macro BOOST_MOVABLE_BUT_NOT_COPYABLE">BOOST_MOVABLE_BUT_NOT_COPYABLE</a>(TYPE) +<a class="link" href="../BOOST_COPYABLE_AND_MOVABLE.html" title="Macro BOOST_COPYABLE_AND_MOVABLE">BOOST_COPYABLE_AND_MOVABLE</a>(TYPE) +<a class="link" href="../BOOST_COPYABLE_AND_MOVABLE_ALT.html" title="Macro BOOST_COPYABLE_AND_MOVABLE_ALT">BOOST_COPYABLE_AND_MOVABLE_ALT</a>(TYPE) +<a class="link" href="../BOOST_RV_REF.html" title="Macro BOOST_RV_REF">BOOST_RV_REF</a>(TYPE) +<a class="link" href="../BOOST_COPY_ASSIGN_REF.html" title="Macro BOOST_COPY_ASSIGN_REF">BOOST_COPY_ASSIGN_REF</a>(TYPE) +<a class="link" href="../BOOST_FWD_REF.html" title="Macro BOOST_FWD_REF">BOOST_FWD_REF</a>(TYPE)</pre> +<pre class="synopsis"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/has_nothrow_move.html" title="Struct template has_nothrow_move">has_nothrow_move</a><span class="special">;</span> + + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> It<span class="special">></span> <span class="keyword">class</span> <a class="link" href="../boost/move_iterator.html" title="Class template move_iterator">move_iterator</a><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> C<span class="special">></span> <span class="keyword">class</span> <a class="link" href="../boost/back_move_insert_iterator.html" title="Class template back_move_insert_iterator">back_move_insert_iterator</a><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> C<span class="special">></span> <span class="keyword">class</span> <a class="link" href="../boost/front_move_insert_iterator.html" title="Class template front_move_insert_iterator">front_move_insert_iterator</a><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> C<span class="special">></span> <span class="keyword">class</span> <a class="link" href="../boost/move_insert_iterator.html" title="Class template move_insert_iterator">move_insert_iterator</a><span class="special">;</span> + + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="keyword">struct</span> <a class="link" href="../boost/has_trivial_destructor__id1117925.html" title="Struct template has_trivial_destructor_after_move">has_trivial_destructor_after_move</a><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="identifier">rvalue_reference</span> <a class="link" href="../boost/move_id1117957.html" title="Function template move"><span class="identifier">move</span></a><span class="special">(</span><span class="identifier">input_reference</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> <span class="identifier">output_reference</span> <a class="link" href="../boost/forward.html" title="Function template forward"><span class="identifier">forward</span></a><span class="special">(</span><span class="identifier">input_reference</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> It<span class="special">></span> <a class="link" href="../boost/move_iterator.html" title="Class template move_iterator">move_iterator</a><span class="special"><</span> <span class="identifier">It</span> <span class="special">></span> <a class="link" href="../boost/make_move_iterator.html" title="Function template make_move_iterator"><span class="identifier">make_move_iterator</span></a><span class="special">(</span><span class="keyword">const</span> <span class="identifier">It</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> C<span class="special">></span> <a class="link" href="../boost/back_move_insert_iterator.html" title="Class template back_move_insert_iterator">back_move_insert_iterator</a><span class="special"><</span> <span class="identifier">C</span> <span class="special">></span> <a class="link" href="../boost/back_move_inserter.html" title="Function template back_move_inserter"><span class="identifier">back_move_inserter</span></a><span class="special">(</span><span class="identifier">C</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> C<span class="special">></span> + <a class="link" href="../boost/front_move_insert_iterator.html" title="Class template front_move_insert_iterator">front_move_insert_iterator</a><span class="special"><</span> <span class="identifier">C</span> <span class="special">></span> <a class="link" href="../boost/front_move_inserter.html" title="Function template front_move_inserter"><span class="identifier">front_move_inserter</span></a><span class="special">(</span><span class="identifier">C</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> C<span class="special">></span> + <span class="identifier">move_insert_iterator</span><span class="special"><</span> <span class="identifier">C</span> <span class="special">></span> <a class="link" href="../boost/move_inserter.html" title="Function template move_inserter"><span class="identifier">move_inserter</span></a><span class="special">(</span><span class="identifier">C</span> <span class="special">&</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">C</span><span class="special">::</span><span class="identifier">iterator</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> I<span class="special">,</span> <span class="keyword">typename</span> O<span class="special">></span> <span class="identifier">O</span> <a class="link" href="../boost/move_id1118143.html" title="Function template move"><span class="identifier">move</span></a><span class="special">(</span><span class="identifier">I</span><span class="special">,</span> <span class="identifier">I</span><span class="special">,</span> <span class="identifier">O</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> I<span class="special">,</span> <span class="keyword">typename</span> O<span class="special">></span> <span class="identifier">O</span> <a class="link" href="../boost/move_backward.html" title="Function template move_backward"><span class="identifier">move_backward</span></a><span class="special">(</span><span class="identifier">I</span><span class="special">,</span> <span class="identifier">I</span><span class="special">,</span> <span class="identifier">O</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> I<span class="special">,</span> <span class="keyword">typename</span> F<span class="special">></span> <span class="identifier">F</span> <a class="link" href="../boost/uninitialized_move.html" title="Function template uninitialized_move"><span class="identifier">uninitialized_move</span></a><span class="special">(</span><span class="identifier">I</span><span class="special">,</span> <span class="identifier">I</span><span class="special">,</span> <span class="identifier">F</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> I<span class="special">,</span> <span class="keyword">typename</span> F<span class="special">></span> <span class="identifier">F</span> <a class="link" href="../boost/uninitialized_copy_or_move.html" title="Function template uninitialized_copy_or_move"><span class="identifier">uninitialized_copy_or_move</span></a><span class="special">(</span><span class="identifier">I</span><span class="special">,</span> <span class="identifier">I</span><span class="special">,</span> <span class="identifier">F</span><span class="special">)</span><span class="special">;</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> I<span class="special">,</span> <span class="keyword">typename</span> F<span class="special">></span> <span class="identifier">F</span> <a class="link" href="../boost/copy_or_move.html" title="Function template copy_or_move"><span class="identifier">copy_or_move</span></a><span class="special">(</span><span class="identifier">I</span><span class="special">,</span> <span class="identifier">I</span><span class="special">,</span> <span class="identifier">F</span><span class="special">)</span><span class="special">;</span> +<span class="special">}</span></pre> +</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 © 2008-2010 Ion Gaztanaga<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> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="release_notes.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="../boost/has_nothrow_move.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/move/release_notes.html b/doc/html/move/release_notes.html new file mode 100755 index 0000000000..07987e9f29 --- /dev/null +++ b/doc/html/move/release_notes.html @@ -0,0 +1,58 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Release Notes</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../move.html" title="Chapter 16. Boost.Move"> +<link rel="prev" href="thanks_to.html" title="Thanks and credits"> +<link rel="next" href="reference.html" title="Reference"> +</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="thanks_to.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="reference.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="move.release_notes"></a><a class="link" href="release_notes.html" title="Release Notes">Release Notes</a> +</h2></div></div></div> +<div class="toc"><dl><dt><span class="section"><a href="release_notes.html#move.release_notes.release_notes_boost_1_49_00">Boost + 1.49 Release</a></span></dt></dl></div> +<div class="section"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="move.release_notes.release_notes_boost_1_49_00"></a><a class="link" href="release_notes.html#move.release_notes.release_notes_boost_1_49_00" title="Boost 1.49 Release">Boost + 1.49 Release</a> +</h3></div></div></div> +<div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> + Fixed bugs <a href="https://svn.boost.org/trac/boost/ticket/6417" target="_top">#6417</a>, + <a href="https://svn.boost.org/trac/boost/ticket/6183" target="_top">#6183</a>, + <a href="https://svn.boost.org/trac/boost/ticket/6185" target="_top">#6185</a>, + <a href="https://svn.boost.org/trac/boost/ticket/6395" target="_top">#6395</a>, + <a href="https://svn.boost.org/trac/boost/ticket/6396" target="_top">#6396</a>, + </li></ul></div> +</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 © 2008-2010 Ion Gaztanaga<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> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="thanks_to.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="reference.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> diff --git a/doc/html/move/thanks_to.html b/doc/html/move/thanks_to.html new file mode 100755 index 0000000000..76a6f45955 --- /dev/null +++ b/doc/html/move/thanks_to.html @@ -0,0 +1,54 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Thanks and credits</title> +<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../move.html" title="Chapter 16. Boost.Move"> +<link rel="prev" href="how_the_library_works.html" title="How the library works"> +<link rel="next" href="release_notes.html" title="Release Notes"> +</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="how_the_library_works.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="release_notes.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="move.thanks_to"></a><a class="link" href="thanks_to.html" title="Thanks and credits">Thanks and credits</a> +</h2></div></div></div> +<p> + Thanks to all that developed ideas for move emulation: the first emulation + was based on Howard Hinnant emulation code for <code class="computeroutput"><span class="identifier">unique_ptr</span></code>, + David Abrahams suggested the use of <code class="computeroutput"><span class="keyword">class</span> + <span class="identifier">rv</span></code> class, and Klaus Triendl discovered + how to bind const rlvalues using <code class="computeroutput"><span class="keyword">class</span> + <span class="identifier">rv</span></code>. + </p> +<p> + Many thanks to all boosters that have tested, reviewed and improved the library. + </p> +</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 © 2008-2010 Ion Gaztanaga<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> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="how_the_library_works.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../move.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="release_notes.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> |