1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Implementation</title> 5<link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../index.html" title="Chapter 1. Boost.Icl"> 8<link rel="up" href="../index.html" title="Chapter 1. Boost.Icl"> 9<link rel="prev" href="customization.html" title="Customization"> 10<link rel="next" href="implementation/complexity.html" title="Complexity"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../boost.png"></td> 15<td align="center"><a href="../../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="customization.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="implementation/complexity.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h2 class="title" style="clear: both"> 27<a name="boost_icl.implementation"></a><a class="link" href="implementation.html" title="Implementation">Implementation</a> 28</h2></div></div></div> 29<div class="toc"><dl class="toc"> 30<dt><span class="section"><a href="implementation.html#boost_icl.implementation.iterative_size">Iterative size</a></span></dt> 31<dt><span class="section"><a href="implementation/complexity.html">Complexity</a></span></dt> 32<dt><span class="section"><a href="implementation/inplace_and_infix_operators.html">Inplace 33 and infix operators</a></span></dt> 34</dl></div> 35<p> 36 The <a class="link" href="interface.html" title="Interface">previous section</a> gave an overview 37 over the interface of the <span class="bold"><strong>icl</strong></span> outlining <a class="link" href="interface.html#boost_icl.interface.class_templates" title="Class templates">class templates</a>, <a class="link" href="interface/associated_types.html" title="Associated Types">associated types</a> and 38 polymorphic <a class="link" href="interface/function_synopsis.html" title="Function Synopsis">functions 39 and operators</a>. In preparation to the <a class="link" href="function_reference.html" title="Function Reference">next 40 section</a>, that describes the <span class="bold"><strong>icl's</strong></span> polymorphic 41 functions in more detail together with <span class="emphasis"><em><span class="bold"><strong>complexity 42 characteristics</strong></span></em></span>, this section summarizes some general 43 information on implementation and performance. 44 </p> 45<h6> 46<a name="boost_icl.implementation.h0"></a> 47 <span class="phrase"><a name="boost_icl.implementation.stl_based_implementation"></a></span><a class="link" href="implementation.html#boost_icl.implementation.stl_based_implementation">STL 48 based implementation</a> 49 </h6> 50<p> 51 The <span class="bold"><strong>implementation</strong></span> of the <span class="bold"><strong>icl's</strong></span> 52 containers is based on <span class="bold"><strong>std::set</strong></span> and <span class="bold"><strong>std::map</strong></span>. So the underlying data structure of interval 53 containers is a red black tree of intervals or interval value pairs. The element 54 containers <a href="http://www.cplusplus.com/reference/stl/set/" target="_top"><code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">set</span></code> 55 </a> and <code class="computeroutput"><a class="link" href="../boost/icl/map.html" title="Class template map">icl::map</a></code> are wrapper 56 classes of <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">set</span></code> and <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">map</span></code>. Interval 57 containers are then using <a href="http://www.cplusplus.com/reference/stl/set/" target="_top"><code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">sets</span></code></a> 58 of intervals or <code class="computeroutput"><a class="link" href="../boost/icl/map.html" title="Class template map">icl::maps</a></code> of interval 59 value pairs as implementing containers. So all the <span class="emphasis"><em><span class="bold"><strong>complexity 60 characteristics</strong></span></em></span> of icl containers are based on and limited 61 by the <span class="emphasis"><em><span class="bold"><strong>red-black tree implementation</strong></span></em></span> 62 of the underlying std::AssociativeContainers. 63 </p> 64<div class="section"> 65<div class="titlepage"><div><div><h3 class="title"> 66<a name="boost_icl.implementation.iterative_size"></a><a class="link" href="implementation.html#boost_icl.implementation.iterative_size" title="Iterative size">Iterative size</a> 67</h3></div></div></div> 68<p> 69 Throughout the documentation on complexity, big <span class="emphasis"><em>O</em></span> expressions 70 like <span class="emphasis"><em>O(n)</em></span> or <span class="emphasis"><em>O(m log n)</em></span> refer to 71 container sizes <span class="emphasis"><em>n</em></span> and <span class="emphasis"><em>m</em></span>. In this 72 documentation these sizes <span class="emphasis"><em><span class="bold"><strong>do not</strong></span></em></span> 73 denote to the familiar <code class="computeroutput"><span class="identifier">size</span></code> 74 function that returns the <span class="emphasis"><em><span class="bold"><strong>number of elements</strong></span></em></span> 75 of a container. Because for an interval container 76</p> 77<pre class="programlisting"><span class="identifier">interval_set</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">mono</span><span class="special">;</span> 78<span class="identifier">mono</span> <span class="special">+=</span> <span class="identifier">interval</span><span class="special"><</span><span class="keyword">int</span><span class="special">>::</span><span class="identifier">closed</span><span class="special">(</span><span class="number">1</span><span class="special">,</span><span class="number">5</span><span class="special">);</span> <span class="comment">// {[1 ... 5]}</span> 79<span class="identifier">mono</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span> <span class="special">==</span> <span class="number">5</span><span class="special">;</span> <span class="comment">// true, 5 elements</span> 80<span class="identifier">mono</span><span class="special">.</span><span class="identifier">interval_count</span><span class="special">()</span> <span class="special">==</span> <span class="number">1</span><span class="special">;</span> <span class="comment">// true, only one interval</span> 81</pre> 82<p> 83 </p> 84<p> 85 it's size and the number of contained intervals is usually different. To 86 refer uniformly to a <span class="emphasis"><em>size</em></span> that matters for iteration, 87 which is the decisive kind of size concerning algorithmic behavior there 88 is a function 89</p> 90<pre class="programlisting"><span class="keyword">bool</span> <span class="identifier">T</span><span class="special">::</span><span class="identifier">iterative_size</span><span class="special">()</span><span class="keyword">const</span><span class="special">;</span> <span class="comment">// Number of entities that can be iterated over.</span> 91</pre> 92<p> 93 for all element and interval containers of the icl. So for complexity statements 94 throughout the icl's documentation the sizes will be <code class="computeroutput"><span class="identifier">iterative_sizes</span></code> 95 and big <span class="emphasis"><em>O</em></span> expressions like <span class="emphasis"><em>O(m log n)</em></span> 96 will refer to sizes 97</p> 98<pre class="programlisting"><span class="identifier">n</span> <span class="special">=</span> <span class="identifier">y</span><span class="special">.</span><span class="identifier">iterative_size</span><span class="special">();</span> 99<span class="identifier">m</span> <span class="special">=</span> <span class="identifier">x</span><span class="special">.</span><span class="identifier">iterative_size</span><span class="special">();</span> 100</pre> 101<p> 102 for containers <code class="computeroutput"><span class="identifier">y</span></code> and <code class="computeroutput"><span class="identifier">x</span></code>. Note that 103</p> 104<pre class="programlisting"><span class="identifier">iterative_size</span></pre> 105<p> 106 refers to the primary entities, that we can iterate over. For interval containers 107 these are intervals or segments. 108</p> 109<pre class="programlisting"><span class="identifier">Itervative_size</span></pre> 110<p> 111 never refers to element iteration for interval containers. 112 </p> 113</div> 114</div> 115<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 116<td align="left"></td> 117<td align="right"><div class="copyright-footer">Copyright © 2007-2010 Joachim 118 Faulhaber<br>Copyright © 1999-2006 Cortex Software 119 GmbH<p> 120 Distributed under the Boost Software License, Version 1.0. (See accompanying 121 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>) 122 </p> 123</div></td> 124</tr></table> 125<hr> 126<div class="spirit-nav"> 127<a accesskey="p" href="customization.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="implementation/complexity.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 128</div> 129</body> 130</html> 131
