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| <div class="section" lang="en"> |
| <div class="titlepage"><div><div><h2 class="title" style="clear: both"> |
| <a name="boost_icl.implementation"></a><a class="link" href="implementation.html" title="Implementation">Implementation</a> |
| </h2></div></div></div> |
| <div class="toc"><dl> |
| <dt><span class="section"><a href="implementation.html#boost_icl.implementation.iterative_size">Iterative size</a></span></dt> |
| <dt><span class="section"><a href="implementation/complexity.html">Complexity</a></span></dt> |
| <dt><span class="section"><a href="implementation/inplace_and_infix_operators.html">Inplace |
| and infix operators</a></span></dt> |
| </dl></div> |
| <p> |
| The <a class="link" href="interface.html" title="Interface">previous section</a> gave an overview |
| 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 |
| polymorphic <a class="link" href="interface/function_synopsis.html" title="Function Synopsis">functions |
| and operators</a>. In preparation to the <a class="link" href="function_reference.html" title="Function Reference">next |
| section</a>, that describes the <span class="bold"><strong>icl's</strong></span> polymorphic |
| functions in more detail together with <span class="emphasis"><em><span class="bold"><strong>complexity |
| characteristics</strong></span></em></span>, this section summarizes some general |
| information on implementation and performance. |
| </p> |
| <a name="boost_icl.implementation.stl_based_implementation"></a><h6> |
| <a name="id1124222"></a> |
| <a class="link" href="implementation.html#boost_icl.implementation.stl_based_implementation">STL based |
| implementation</a> |
| </h6> |
| <p> |
| The <span class="bold"><strong>implementation</strong></span> of the <span class="bold"><strong>icl's</strong></span> |
| 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 |
| containers is a red black tree of intervals or interval value pairs. The element |
| 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> |
| </a> and <code class="computeroutput"><a class="link" href="../boost/icl/map.html" title="Class template map">icl::map</a></code> are wrapper |
| 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 |
| 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> |
| of intervals or <code class="computeroutput"><a class="link" href="../boost/icl/map.html" title="Class template map">icl::maps</a></code> of interval |
| value pairs as implementing containers. So all the <span class="emphasis"><em><span class="bold"><strong>complexity |
| characteristics</strong></span></em></span> of icl containers are based on and limited |
| by the <span class="emphasis"><em><span class="bold"><strong>red-black tree implementation</strong></span></em></span> |
| of the underlying std::AssociativeContainers. |
| </p> |
| <div class="section" lang="en"> |
| <div class="titlepage"><div><div><h3 class="title"> |
| <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> |
| </h3></div></div></div> |
| <p> |
| Throughout the documentation on complexity, big <span class="emphasis"><em>O</em></span> expressions |
| like <span class="emphasis"><em>O(n)</em></span> or <span class="emphasis"><em>O(m log n)</em></span> refer to |
| container sizes <span class="emphasis"><em>n</em></span> and <span class="emphasis"><em>m</em></span>. In this |
| documentation these sizes <span class="emphasis"><em><span class="bold"><strong>do not</strong></span></em></span> |
| denote to the familiar <code class="computeroutput"><span class="identifier">size</span></code> |
| function that returns the <span class="emphasis"><em><span class="bold"><strong>number of elements</strong></span></em></span> |
| of a container. Because for an interval container |
| </p> |
| <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> |
| <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><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><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></pre> |
| <p> |
| </p> |
| <p> |
| it's size and the number of contained intervals is usually different. To |
| refer uniformly to a <span class="emphasis"><em>size</em></span> that matters for iteration, |
| which is the decisive kind of size concerning algorithmic behavior there |
| is a function |
| </p> |
| <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></pre> |
| <p> |
| for all element and interval containers of the icl. So for complexity statements |
| throughout the icl's documentation the sizes will be <code class="computeroutput"><span class="identifier">iterative_sizes</span></code> |
| and big <span class="emphasis"><em>O</em></span> expressions like <span class="emphasis"><em>O(m log n)</em></span> |
| will refer to sizes |
| </p> |
| <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> |
| <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> |
| </pre> |
| <p> |
| for containers <code class="computeroutput"><span class="identifier">y</span></code> and <code class="computeroutput"><span class="identifier">x</span></code>. Note that |
| </p> |
| <pre class="programlisting"><span class="identifier">iterative_size</span></pre> |
| <p> |
| refers to the primary entities, that we can iterate over. For interval containers |
| these are intervals or segments. |
| </p> |
| <pre class="programlisting"><span class="identifier">Itervative_size</span></pre> |
| <p> |
| never refers to element iteration for interval containers. |
| </p> |
| </div> |
| </div> |
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| <td align="right"><div class="copyright-footer">Copyright © 2007 -2010 Joachim Faulhaber<br>Copyright © 1999 -2006 Cortex Software GmbH<p> |
| Distributed under the Boost Software License, Version 1.0. (See accompanying |
| file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) |
| </p> |
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