<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0.1 Transitional//EN"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>Boost.Flyweight Documentation - Factories reference</title> <link rel="stylesheet" href="../style.css" type="text/css"> <link rel="start" href="../index.html"> <link rel="prev" href="tags.html"> <link rel="up" href="index.html"> <link rel="next" href="holders.html"> </head> <body> <h1><img src="../../../../boost.png" alt="Boost logo" align= "middle" width="277" height="86">Boost.Flyweight Factories reference</h1> <div class="prev_link"><a href="tags.html"><img src="../prev.gif" alt="tags" border="0"><br> Tags </a></div> <div class="up_link"><a href="index.html"><img src="../up.gif" alt="Boost.Flyweight reference" border="0"><br> Boost.Flyweight reference </a></div> <div class="next_link"><a href="holders.html"><img src="../next.gif" alt="holders" border="0"><br> Holders </a></div><br clear="all" style="clear: all;"> <hr> <h2>Contents</h2> <ul> <li><a href="#factory">Factories and factory specifiers</a></li> <li><a href="#factory_tag_synopsis">Header <code>"boost/flyweight/factory_tag.hpp"</code> synopsis</a> <ul> <li><a href="#is_factory">Class template <code>is_factory</code></a></li> <li><a href="#factory_construct">Class template <code>factory</code></a></li> </ul> </li> <li><a href="#hashed_factory_fwd_synopsis">Header <code>"boost/flyweight/hashed_factory_fwd.hpp"</code> synopsis</a> </li> <li><a href="#hashed_factory_synopsis">Header <code>"boost/flyweight/hashed_factory.hpp"</code> synopsis</a> <ul> <li><a href="#hashed_factory_class">Class template <code>hashed_factory_class</code></a></li> <li><a href="#hashed_factory">Class template <code>hashed_factory</code></a></li> </ul> </li> <li><a href="#set_factory_fwd_synopsis">Header <code>"boost/flyweight/set_factory_fwd.hpp"</code> synopsis</a> </li> <li><a href="#set_factory_synopsis">Header <code>"boost/flyweight/set_factory.hpp"</code> synopsis</a> <ul> <li><a href="#set_factory_class">Class template <code>set_factory_class</code></a></li> <li><a href="#set_factory">Class template <code>set_factory</code></a></li> </ul> </li> <li><a href="#assoc_container_factory_fwd_synopsis">Header <code>"boost/flyweight/assoc_container_factory_fwd.hpp"</code> synopsis</a> </li> <li><a href="#assoc_container_factory_synopsis">Header <code>"boost/flyweight/assoc_container_factory.hpp"</code> synopsis</a> <ul> <li><a href="#assoc_container_factory_class">Class template <code>assoc_container_factory_class</code></a></li> <li><a href="#assoc_container_factory">Class template <code>assoc_container_factory</code></a></li> </ul> </li> </ul> <h2><a name="factory">Factories and factory specifiers</a></h2> <p> Given a type <code>Key</code> and an <a href="http://www.sgi.com/tech/stl/Assignable.html"><code>Assignable</code></a> type <code>Entry</code> implicitly convertible to <code>const Key&</code>, a <i>factory of <code>Entry</code> elements</i> (implicitly associated to <code>Key</code>) is a <a href="http://www.sgi.com/tech/stl/DefaultConstructible.html"><code>Default Constructible</code></a> entity able to store and retrieve immutable elements of type <code>Entry</code>. A factory is governed by an associated equivalence relation defined on <code>Key</code> so that no two <code>Entry</code> objects convertible to equivalent <code>Key</code>s can be stored simultaneously in the factory. Different factory types can use different equivalence relations. </p> <p> In the following table, <code>Factory</code> is a factory of elements of type <code>Entry</code>, <code>f</code> denotes an object of type <code>Factory</code>, <code>x</code> is an object of type <code>Entry</code> and <code>h</code> is a value of <code>Factory::handle_type</code>. </p> <p align="center"> <table cellspacing="0"> <caption><b>Factory requirements.</b></caption> <tr> <th align="center">expression</th> <th align="center">return type</th> <th align="center">assertion/note<br>pre/post-condition</th> </tr> <tr> <td><code>Factory::handle_type</code></td> <td>handle to elements of type <code>T</code><br> stored in the factory </td> <td><code>handle_type</code> is <a href="http://www.sgi.com/tech/stl/Assignable.html"><code>Assignable</code></a> and its copy and<br> assignment operations never throw an exception. </td> </tr> <tr class="odd_tr"> <td><code>f.insert(x);</code></td> <td><code>handle_type</code></td> <td>Inserts a copy of <code>x</code> if there is no equivalent entry in <code>f</code>;<br> returns a handle to the inserted or equivalent element. </td> </tr> <tr> <td><code>f.erase(h);</code></td> <td><code>void</code></td> <td>Erases the element associated to <code>h</code>.<br> This operation does not throw. </td> </tr> <tr class="odd_tr"> <td><code>f.entry(h);</code></td> <td><code>const Entry&</code></td> <td>Returns a reference to the element associated to <code>h</code>.<br> This operation does not throw. </td> </tr> </table> </p> <p> Additionally to the basic thread safety guarantee which is implicitly assumed for most classes including the majority of components of the C++ standard library, it is required that the member function <code>entry</code> can be invoked simultaneously from different threads, even in the presence of concurrent accesses to <code>insert</code> and <code>erase</code> (as long as the entry returned by <code>entry</code> is not the one which is being erased). </p> <p> A type <code>S</code> is said to be a <i>factory specifier</i> if: <ol> <li>One of the following conditions is satisfied: <ol type="a"> <li><a href="#is_factory"><code>is_factory<S>::type</code></a> is <a href="../../../mpl/doc/refmanual/bool.html"><code>boost::mpl::true_</code></a>,</li> <li><code>S</code> is of the form <a href="#factory_construct"><code>factory<S'></code></a>.</li> </ol> </li> <li><code>S</code>, or <code>S'</code> if (b) applies, is an <a href="../../../mpl/doc/refmanual/lambda-expression.html"><code>MPL Lambda Expression</code></a> such that invoking it with types (<code>Entry</code>, <code>Key</code>) resolves to a factory type of <code>Entry</code> elements (implicitly associated to <code>Key</code>). </li> </ol> </p> <h2><a name="factory_tag_synopsis">Header <a href="../../../../boost/flyweight/factory_tag.hpp"><code>"boost/flyweight/factory_tag.hpp"</code></a> synopsis</a></h2> <blockquote><pre> <span class=keyword>namespace</span> <span class=identifier>boost</span><span class=special>{</span> <span class=keyword>namespace</span> <span class=identifier>flyweights</span><span class=special>{</span> <span class=keyword>struct</span> <span class=identifier>factory_marker</span><span class=special>;</span> <span class=keyword>template</span><span class=special><</span><span class=keyword>typename</span> <span class=identifier>T</span><span class=special>></span> <span class=keyword>struct</span> <span class=identifier>is_factory</span><span class=special>;</span> <span class=keyword>template</span><span class=special><</span><span class=keyword>typename</span> <span class=identifier>T</span><span class=special>></span> <span class=keyword>struct</span> <span class=identifier>factory</span><span class=special>;</span> <span class=special>}</span> <span class=comment>// namespace boost::flyweights</span> <span class=special>}</span> <span class=comment>// namespace boost</span> </pre></blockquote> <h3><a name="is_factory">Class template <code>is_factory</code></a></h3> <p> Unless specialized by the user, <code>is_factory<T>::type</code> is <a href="../../../mpl/doc/refmanual/bool.html"><code>boost::mpl::true_</code></a> if <code>T</code> is derived from <code>factory_marker</code>, and it is <a href="../../../mpl/doc/refmanual/bool.html"><code>boost::mpl::false_</code></a> otherwise. </p> <h3><a name="factory_construct">Class template <code>factory</code></a></h3> <p> <code>factory<T></code> is a syntactic construct meant to indicate that <code>T</code> is a factory specifier without resorting to the mechanisms provided by the <code>is_factory</code> class template. </p> <h2><a name="hashed_factory_fwd_synopsis">Header <a href="../../../../boost/flyweight/hashed_factory_fwd.hpp"><code>"boost/flyweight/hashed_factory_fwd.hpp"</code></a> synopsis</a></h2> <blockquote><pre> <span class=keyword>namespace</span> <span class=identifier>boost</span><span class=special>{</span> <span class=keyword>namespace</span> <span class=identifier>flyweights</span><span class=special>{</span> <span class=keyword>template</span><span class=special><</span> <span class=keyword>typename</span> <span class=identifier>Entry</span><span class=special>,</span><span class=keyword>typename</span> <span class=identifier>Key</span><span class=special>,</span> <span class=keyword>typename</span> <span class=identifier>Hash</span><span class=special>=</span><b>implementation defined</b><span class=special>,</span> <span class=keyword>typename</span> <span class=identifier>Pred</span><span class=special>=</span><b>implementation defined</b><span class=special>,</span> <span class=keyword>typename</span> <span class=identifier>Allocator</span><span class=special>=</span><b>implementation defined</b> <span class=special>></span> <span class=keyword>class</span> <span class=identifier>hashed_factory_class</span><span class=special>;</span> <span class=keyword>template</span><span class=special><</span> <span class=keyword>typename</span> <span class=identifier>Hash</span><span class=special>=</span><b>implementation defined</b><span class=special>,</span> <span class=keyword>typename</span> <span class=identifier>Pred</span><span class=special>=</span><b>implementation defined</b><span class=special>,</span> <span class=keyword>typename</span> <span class=identifier>Allocator</span><span class=special>=</span><b>implementation defined</b> <span class=special>></span> <span class=keyword>struct</span> <span class=identifier>hashed_factory</span><span class=special>;</span> <span class=special>}</span> <span class=comment>// namespace boost::flyweights</span> <span class=special>}</span> <span class=comment>// namespace boost</span> </pre></blockquote> <p> <code>hashed_factory_fwd.hpp</code> forward declares the class templates <a href="#hashed_factory_class"><code>hashed_factory_class</code></a> and <a href="#hashed_factory"><code>hashed_factory</code></a>. </p> <h2><a name="hashed_factory_synopsis">Header <a href="../../../../boost/flyweight/hashed_factory.hpp"><code>"boost/flyweight/hashed_factory.hpp"</code></a> synopsis</a></h2> <h3><a name="hashed_factory_class">Class template <code>hashed_factory_class</code></a></h3> <p> <code>hashed_factory_class</code> is a <a href="#factory"><code>Factory</code></a> implemented with a hashed container. </p> <blockquote><pre> <span class=keyword>template</span><span class=special><</span> <span class=keyword>typename</span> <span class=identifier>Entry</span><span class=special>,</span><span class=keyword>typename</span> <span class=identifier>Key</span><span class=special>,</span> <span class=keyword>typename</span> <span class=identifier>Hash</span><span class=special>,</span><span class=keyword>typename</span> <span class=identifier>Pred</span><span class=special>,</span><span class=keyword>typename</span> <span class=identifier>Allocator</span> <span class=special>></span> <span class=keyword>class</span> <span class=identifier>hashed_factory_class</span> <span class=special>{</span> <span class=keyword>public</span><span class=special>:</span> <span class=keyword>typedef</span> <b>implementation defined</b> <span class=identifier>handle_type</span><span class=special>;</span> <span class=identifier>handle_type</span> <span class=identifier>insert</span><span class=special>(</span><span class=keyword>const</span> <span class=identifier>Entry</span><span class=special>&</span> <span class=identifier>x</span><span class=special>);</span> <span class=keyword>void</span> <span class=identifier>erase</span><span class=special>(</span><span class=identifier>handle_type</span> <span class=identifier>h</span><span class=special>);</span> <span class=keyword>const</span> <span class=identifier>Entry</span><span class=special>&</span> <span class=identifier>entry</span><span class=special>(</span><span class=identifier>handle_type</span> <span class=identifier>h</span><span class=special>);</span> <span class=special>};</span> </pre></blockquote> <p> <code>Hash</code> is a <a href="http://www.sgi.com/tech/stl/DefaultConstructible.html"><code>Default Constructible</code></a> <a href="http://www.sgi.com/tech/stl/UnaryFunction.html"><code>Unary Function</code></a> taking a single argument of type <code>Key</code> and returning a value of type <code>std::size_t</code> in the range <code>[0, std::numeric_limits<std::size_t>::max())</code>. <code>Pred</code> is a <a href="http://www.sgi.com/tech/stl/DefaultConstructible.html"><code>Default Constructible</code></a> <a href="http://www.sgi.com/tech/stl/BinaryPredicate.html"> <code>Binary Predicate</code></a> inducing an equivalence relation on elements of <code>Key</code>. It is required that a <code>Hash</code> object return the same value for objects equivalent under <code>Pred</code>. The equivalence relation on <code>Key</code> associated to the factory is that induced by <code>Pred</code>. The default arguments for <code>Hash</code> and <code>Pred</code> are <a href="../../../functional/hash/index.html"><code>boost::hash<Key></code></a> and <code>std::equal_to<Key></code>, respectively. <code>Allocator</code> must be an allocator of <code>Entry</code> objects satisfying the associated C++ requirements at <b>[lib.allocator.requirements]</b>. The default argument is <code>std::allocator<Entry></code>. The internal hashed container upon which <code>hashed_factory_class</code> is based is constructed with default initialized objects of type <code>Hash</code>, <code>Pred</code> and <code>Allocator</code>. </p> <h3><a name="hashed_factory">Class template <code>hashed_factory</code></a></h3> <p> <a href="#factory"><code>Factory Specifier</code></a> for <a href="#hashed_factory_class"><code>hashed_factory_class</code></a>. </p> <blockquote><pre> <span class=keyword>template</span><span class=special><</span><span class=keyword>typename</span> <span class=identifier>Hash</span><span class=special>,</span><span class=keyword>typename</span> <span class=identifier>Pred</span><span class=special>,</span><span class=keyword>typename</span> <span class=identifier>Allocator</span><span class=special>></span> <span class=keyword>struct</span> <span class=identifier>hashed_factory</span><span class=special>;</span> </pre></blockquote> <p> <code>hashed_factory<Hash,Pred,Allocator></code> is an <a href="../../../mpl/doc/refmanual/metafunction-class.html"><code>MPL Metafunction Class</code></a> such that the type </p> <blockquote><pre> <span class=identifier>boost</span><span class=special>::</span><span class=identifier>mpl</span><span class=special>::</span><span class=identifier>apply</span><span class=special><</span> <span class=identifier>hashed_factory</span><span class=special><</span><span class=identifier>Hash</span><span class=special>,</span><span class=identifier>Pred</span><span class=special>,</span><span class=identifier>Allocator</span><span class=special>>,</span> <span class=identifier>Entry</span><span class=special>,</span><span class=identifier>Key</span> <span class=special>>::</span><span class=identifier>type</span> </pre></blockquote> <p> is the same as </p> <blockquote><pre> <span class=identifier>boost</span><span class=special>::</span><span class=identifier>mpl</span><span class=special>::</span><span class=identifier>apply</span><span class=special><</span> <span class=identifier>hashed_factory_class</span><span class=special><</span><span class=identifier>boost</span><span class=special>::</span><span class=identifier>mpl</span><span class=special>::</span><span class=identifier>_1</span><span class=special>,</span><span class=identifier>boost</span><span class=special>::</span><span class=identifier>mpl</span><span class=special>::</span><span class=identifier>_2</span><span class=special>,</span><span class=identifier>Hash</span><span class=special>,</span><span class=identifier>Pred</span><span class=special>,</span><span class=identifier>Allocator</span><span class=special>>,</span> <span class=identifier>Entry</span><span class=special>,</span><span class=identifier>Key</span> <span class=special>>::</span><span class=identifier>type</span> </pre></blockquote> <p> This implies that <code>Hash</code>, <code>Pred</code> and <code>Allocator</code> can be <a href="../../../mpl/doc/refmanual/placeholder-expression.html"><code>MPL Placeholder Expressions</code></a> resolving to the actual types used by <code>hashed_factory_class</code>. </p> <h2><a name="set_factory_fwd_synopsis">Header <a href="../../../../boost/flyweight/set_factory_fwd.hpp"><code>"boost/flyweight/set_factory_fwd.hpp"</code></a> synopsis</a></h2> <blockquote><pre> <span class=keyword>namespace</span> <span class=identifier>boost</span><span class=special>{</span> <span class=keyword>namespace</span> <span class=identifier>flyweights</span><span class=special>{</span> <span class=keyword>template</span><span class=special><</span> <span class=keyword>typename</span> <span class=identifier>Entry</span><span class=special>,</span><span class=keyword>typename</span> <span class=identifier>Key</span><span class=special>,</span> <span class=keyword>typename</span> <span class=identifier>Compare</span><span class=special>=</span><b>implementation defined</b><span class=special>,</span> <span class=keyword>typename</span> <span class=identifier>Allocator</span><span class=special>=</span><b>implementation defined</b> <span class=special>></span> <span class=keyword>class</span> <span class=identifier>set_factory_class</span><span class=special>;</span> <span class=keyword>template</span><span class=special><</span> <span class=keyword>typename</span> <span class=identifier>Compare</span><span class=special>=</span><b>implementation defined</b><span class=special>,</span> <span class=keyword>typename</span> <span class=identifier>Allocator</span><span class=special>=</span><b>implementation defined</b> <span class=special>></span> <span class=keyword>struct</span> <span class=identifier>set_factory</span><span class=special>;</span> <span class=special>}</span> <span class=comment>// namespace boost::flyweights</span> <span class=special>}</span> <span class=comment>// namespace boost</span> </pre></blockquote> <p> <code>set_factory_fwd.hpp</code> forward declares the class templates <a href="#set_factory_class"><code>set_factory_class</code></a> and <a href="#set_factory"><code>set_factory</code></a>. </p> <h2><a name="set_factory_synopsis">Header <a href="../../../../boost/flyweight/set_factory.hpp"><code>"boost/flyweight/set_factory.hpp"</code></a> synopsis</a></h2> <h3><a name="set_factory_class">Class template <code>set_factory_class</code></a></h3> <p> <code>set_factory_class</code> is a <a href="#factory"><code>Factory</code></a> implemented on top of an orderded associative container. </p> <blockquote><pre> <span class=keyword>template</span><span class=special><</span> <span class=keyword>typename</span> <span class=identifier>Entry</span><span class=special>,</span><span class=keyword>typename</span> <span class=identifier>Key</span><span class=special>,</span> <span class=keyword>typename</span> <span class=identifier>Compare</span><span class=special>,</span><span class=keyword>typename</span> <span class=identifier>Allocator</span> <span class=special>></span> <span class=keyword>class</span> <span class=identifier>set_factory_class</span> <span class=special>{</span> <span class=keyword>public</span><span class=special>:</span> <span class=keyword>typedef</span> <b>implementation defined</b> <span class=identifier>handle_type</span><span class=special>;</span> <span class=identifier>handle_type</span> <span class=identifier>insert</span><span class=special>(</span><span class=keyword>const</span> <span class=identifier>Entry</span><span class=special>&</span> <span class=identifier>x</span><span class=special>);</span> <span class=keyword>void</span> <span class=identifier>erase</span><span class=special>(</span><span class=identifier>handle_type</span> <span class=identifier>h</span><span class=special>);</span> <span class=keyword>const</span> <span class=identifier>Entry</span><span class=special>&</span> <span class=identifier>entry</span><span class=special>(</span><span class=identifier>handle_type</span> <span class=identifier>h</span><span class=special>);</span> <span class=special>};</span> </pre></blockquote> <p> <code>Compare</code> is a <a href="http://www.sgi.com/tech/stl/DefaultConstructible.html"><code>Default Constructible</code></a> <a href="http://www.sgi.com/tech/stl/StrictWeakOrdering.html"> <code>Strict Weak Ordering</code></a> on <code>Key</code>. Two <code>Key</code>s <code>x</code> and <code>y</code> are considered equivalent if <code>!c(x,y)&&!c(y,x)</code> for <code>c</code> of type <code>Compare</code>. The default argument of <code>Compare</code> is <code>std::less<Key></code> <code>Allocator</code> must be an allocator of <code>Entry</code> objects satisfying the associated C++ requirements at <b>[lib.allocator.requirements]</b>. The default argument is <code>std::allocator<Entry></code>. The internal container upon which <code>set_factory_class</code> is based is constructed with default initialized objects of type <code>Compare</code> and <code>Allocator</code>. </p> <h3><a name="set_factory">Class template <code>set_factory</code></a></h3> <p> <a href="#factory"><code>Factory Specifier</code></a> for <a href="#set_factory_class"><code>set_factory_class</code></a>. </p> <blockquote><pre> <span class=keyword>template</span><span class=special><</span><span class=keyword>typename</span> <span class=identifier>Compare</span><span class=special>,</span><span class=keyword>typename</span> <span class=identifier>Allocator</span><span class=special>></span> <span class=keyword>struct</span> <span class=identifier>set_factory</span><span class=special>;</span> </pre></blockquote> <p> <code>set_factory<Compare,Allocator></code> is an <a href="../../../mpl/doc/refmanual/metafunction-class.html"><code>MPL Metafunction Class</code></a> such that the type </p> <blockquote><pre> <span class=identifier>boost</span><span class=special>::</span><span class=identifier>mpl</span><span class=special>::</span><span class=identifier>apply</span><span class=special><</span> <span class=identifier>set_factory</span><span class=special><</span><span class=identifier>Compare</span><span class=special>,</span><span class=identifier>Allocator</span><span class=special>>,</span> <span class=identifier>Entry</span><span class=special>,</span><span class=identifier>Key</span> <span class=special>>::</span><span class=identifier>type</span> </pre></blockquote> <p> is the same as </p> <blockquote><pre> <span class=identifier>boost</span><span class=special>::</span><span class=identifier>mpl</span><span class=special>::</span><span class=identifier>apply</span><span class=special><</span> <span class=identifier>set_factory_class</span><span class=special><</span><span class=identifier>boost</span><span class=special>::</span><span class=identifier>mpl</span><span class=special>::</span><span class=identifier>_1</span><span class=special>,</span><span class=identifier>boost</span><span class=special>::</span><span class=identifier>mpl</span><span class=special>::</span><span class=identifier>_2</span><span class=special>,</span><span class=identifier>Compare</span><span class=special>,</span><span class=identifier>Allocator</span><span class=special>>,</span> <span class=identifier>Entry</span><span class=special>,</span><span class=identifier>Key</span> <span class=special>>::</span><span class=identifier>type</span> </pre></blockquote> <p> This implies that <code>Compare</code> and <code>Allocator</code> can be <a href="../../../mpl/doc/refmanual/placeholder-expression.html"><code>MPL Placeholder Expressions</code></a> resolving to the actual types used by <code>set_factory_class</code>. </p> <h2><a name="assoc_container_factory_fwd_synopsis">Header <a href="../../../../boost/flyweight/assoc_container_factory_fwd.hpp"><code>"boost/flyweight/assoc_container_factory_fwd.hpp"</code></a> synopsis</a></h2> <blockquote><pre> <span class=keyword>namespace</span> <span class=identifier>boost</span><span class=special>{</span> <span class=keyword>namespace</span> <span class=identifier>flyweights</span><span class=special>{</span> <span class=keyword>template</span><span class=special><</span><span class=keyword>typename</span> <span class=identifier>Container</span><span class=special>></span> <span class=keyword>class</span> <span class=identifier>assoc_container_factory_class</span><span class=special>;</span> <span class=keyword>template</span><span class=special><</span><span class=keyword>typename</span> <span class=identifier>ContainerSpecifier</span><span class=special>></span> <span class=keyword>struct</span> <span class=identifier>assoc_container_factory</span><span class=special>;</span> <span class=special>}</span> <span class=comment>// namespace boost::flyweights</span> <span class=special>}</span> <span class=comment>// namespace boost</span> </pre></blockquote> <p> <code>assoc_container_factory_fwd.hpp</code> forward declares the class templates <a href="#assoc_container_factory_class"><code>assoc_container_factory_class</code></a> and <a href="#assoc_container_factory"><code>assoc_container_factory</code></a>. </p> <h2><a name="assoc_container_factory_synopsis">Header <a href="../../../../boost/flyweight/assoc_container_factory.hpp"><code>"boost/flyweight/assoc_container_factory.hpp"</code></a> synopsis</a></h2> <h3><a name="assoc_container_factory_class">Class template <code>assoc_container_factory_class</code></a></h3> <p> <code>assoc_container_factory_class</code> wraps a suitable associative container to provide a <a href="#factory"><code>Factory</code></a> interface. </p> <blockquote><pre> <span class=keyword>template</span><span class=special><</span><span class=keyword>typename</span> <span class=identifier>Container</span><span class=special>></span> <span class=keyword>class</span> <span class=identifier>assoc_container_factory_class</span> <span class=special>{</span> <span class=keyword>public</span><span class=special>:</span> <span class=keyword>typedef</span> <span class=keyword>typename</span> <span class=identifier>Container</span><span class=special>::</span><span class=identifier>iterator</span> <span class=identifier>handle_type</span><span class=special>;</span> <span class=identifier>handle_type</span> <span class=identifier>insert</span><span class=special>(</span><span class=keyword>const</span> <span class=keyword>typename</span> <span class=identifier>Container</span><span class=special>::</span><span class=identifier>value_type</span><span class=special>&</span> <span class=identifier>x</span><span class=special>);</span> <span class=keyword>void</span> <span class=identifier>erase</span><span class=special>(</span><span class=identifier>handle_type</span> <span class=identifier>h</span><span class=special>);</span> <span class=keyword>const</span> <span class=keyword>typename</span> <span class=identifier>Container</span><span class=special>::</span><span class=identifier>value_type</span><span class=special>&</span> <span class=identifier>entry</span><span class=special>(</span><span class=identifier>handle_type</span> <span class=identifier>h</span><span class=special>);</span> <span class=special>};</span> </pre></blockquote> <p> <code>Container</code> must be an (ordered or unordered) associative container such that <ol> <li><code>Container::key_type</code> is the same as <code>Container::value_type</code> (which is the entry type associated to the factory). </li> <li>Unique keys (rather than equivalent keys) are supported.</li> <li><code>Container</code> is <i>stable</i>, i.e. its iterators are not invalidated upon insert or erase operations.</li> </ol> The equivalence relation associated to <code>assoc_container_factory_class</code> is the one induced by <code>Container</code>. If equivalence of elements of <code>Container::value_type</code> is determined solely on the basis of a type <code>value_type'</code> to which <code>value_type</code> is implicitly convertible, then <code>assoc_container_factory_class</code> is a factory of entries of type <code>value_type</code> implicitly associated to <code>value_type'</code>. For example, the instantiation </p> <blockquote><pre> <span class=identifier>assoc_container_factory_class</span><span class=special><</span> <span class=identifier>std</span><span class=special>::</span><span class=identifier>set</span><span class=special><</span><span class=identifier>derived</span><span class=special>,</span><span class=identifier>std</span><span class=special>::</span><span class=identifier>less</span><span class=special><</span><span class=identifier>base</span><span class=special>></span> <span class=special>></span> <span class=comment>// derived inherits from base</span> <span class=special>></span> </pre></blockquote> <p> is a factory of <code>derived</code> elements implicitly associated to <code>base</code>. </p> <h3><a name="assoc_container_factory">Class template <code>assoc_container_factory</code></a></h3> <p> <a href="#factory"><code>Factory Specifier</code></a> for <a href="#assoc_container_factory_class"><code>assoc_container_factory_class</code></a>. </p> <blockquote><pre> <span class=keyword>template</span><span class=special><</span><span class=keyword>typename</span> <span class=identifier>ContainerSpecifier</span><span class=special>></span> <span class=keyword>struct</span> <span class=identifier>assoc_container_factory</span><span class=special>;</span> </pre></blockquote> <p> <code>ContainerSpecifier</code> must be an <a href="../../../mpl/doc/refmanual/lambda-expression.html"><code>MPL Lambda Expression</code></a> resolving, when invoked with (<code>Entry</code>, <code>Key</code>), to a type <code>Container</code> such that <code>assoc_container_factory_class<Container></code> is a factory of <code>Entry</code> elements implicitly associated to <code>Key</code>. </p> <hr> <div class="prev_link"><a href="tags.html"><img src="../prev.gif" alt="tags" border="0"><br> Tags </a></div> <div class="up_link"><a href="index.html"><img src="../up.gif" alt="Boost.Flyweight reference" border="0"><br> Boost.Flyweight reference </a></div> <div class="next_link"><a href="holders.html"><img src="../next.gif" alt="holders" border="0"><br> Holders </a></div><br clear="all" style="clear: all;"> <br> <p>Revised August 13th 2008</p> <p>© Copyright 2006-2008 Joaquín M López Muñoz. Distributed under the Boost Software License, Version 1.0. (See accompanying file <a href="../../../../LICENSE_1_0.txt"> LICENSE_1_0.txt</a> or copy at <a href="http://www.boost.org/LICENSE_1_0.txt"> http://www.boost.org/LICENSE_1_0.txt</a>) </p> </body> </html>