3 <meta http-equiv=
"Content-Type" content=
"text/html; charset=US-ASCII">
4 <title>Std transform
</title>
5 <link rel=
"stylesheet" href=
"../../../../../../doc/src/boostbook.css" type=
"text/css">
6 <meta name=
"generator" content=
"DocBook XSL Stylesheets V1.74.0">
7 <link rel=
"home" href=
"../../index.html" title=
"Chapter 1. Boost.Icl">
8 <link rel=
"up" href=
"../examples.html" title=
"Examples">
9 <link rel=
"prev" href=
"std_copy.html" title=
"Std copy">
10 <link rel=
"next" href=
"custom_interval.html" title=
"Custom interval">
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>
22 <div class=
"spirit-nav">
23 <a accesskey=
"p" href=
"std_copy.html"><img src=
"../../../../../../doc/src/images/prev.png" alt=
"Prev"></a><a accesskey=
"u" href=
"../examples.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=
"custom_interval.html"><img src=
"../../../../../../doc/src/images/next.png" alt=
"Next"></a>
25 <div class=
"section boost_icl_examples_std_transform" lang=
"en">
26 <div class=
"titlepage"><div><div><h3 class=
"title">
27 <a name=
"boost_icl.examples.std_transform"></a><a class=
"link" href=
"std_transform.html" title=
"Std transform">Std transform
</a>
28 </h3></div></div></div>
30 Instead of writing loops, the standard algorithm
<a href=
"http://www.cplusplus.com/reference/algorithm/transform/" target=
"_top"><code class=
"computeroutput"><span class=
"identifier">std
</span><span class=
"special">::
</span><span class=
"identifier">transform
</span></code></a>
31 can be used to fill interval containers from std containers of user defined
32 objects. We need a function, that maps the
<span class=
"emphasis"><em>user defined object
</em></span>
33 into the
<span class=
"emphasis"><em>segement type
</em></span> of an interval map or the
<span class=
"emphasis"><em>interval
34 type
</em></span> of an interval set. Based on that we can use
<code class=
"computeroutput"><span class=
"identifier">std
</span><span class=
"special">::
</span><span class=
"identifier">transform
</span></code>
35 with an
<code class=
"computeroutput"><span class=
"identifier">icl
</span><span class=
"special">::
</span><span class=
"identifier">inserter
</span></code> or
<code class=
"computeroutput"><span class=
"identifier">icl
</span><span class=
"special">::
</span><span class=
"identifier">adder
</span></code>
36 to transform the user objects into interval containers.
43 <pre class=
"programlisting"><span class=
"preprocessor">#include
</span> <span class=
"special"><</span><span class=
"identifier">iostream
</span><span class=
"special">></span>
44 <span class=
"preprocessor">#include
</span> <span class=
"special"><</span><span class=
"identifier">vector
</span><span class=
"special">></span>
45 <span class=
"preprocessor">#include
</span> <span class=
"special"><</span><span class=
"identifier">algorithm
</span><span class=
"special">></span>
46 <span class=
"preprocessor">#include
</span> <span class=
"special"><</span><span class=
"identifier">boost
</span><span class=
"special">/
</span><span class=
"identifier">icl
</span><span class=
"special">/
</span><span class=
"identifier">split_interval_map
</span><span class=
"special">.
</span><span class=
"identifier">hpp
</span><span class=
"special">></span>
47 <span class=
"preprocessor">#include
</span> <span class=
"special"><</span><span class=
"identifier">boost
</span><span class=
"special">/
</span><span class=
"identifier">icl
</span><span class=
"special">/
</span><span class=
"identifier">separate_interval_set
</span><span class=
"special">.
</span><span class=
"identifier">hpp
</span><span class=
"special">></span>
49 <span class=
"keyword">using
</span> <span class=
"keyword">namespace
</span> <span class=
"identifier">std
</span><span class=
"special">;
</span>
50 <span class=
"keyword">using
</span> <span class=
"keyword">namespace
</span> <span class=
"identifier">boost
</span><span class=
"special">;
</span>
51 <span class=
"keyword">using
</span> <span class=
"keyword">namespace
</span> <span class=
"identifier">boost
</span><span class=
"special">::
</span><span class=
"identifier">icl
</span><span class=
"special">;
</span>
53 <span class=
"comment">// Suppose we are working with a class called MyObject, containing some
54 </span><span class=
"comment">// information about interval bounds e.g. _from, _to and some data members
55 </span><span class=
"comment">// that carry associated information like e.g. _value.
56 </span><span class=
"keyword">class
</span> <span class=
"identifier">MyObject
</span>
57 <span class=
"special">{
</span>
58 <span class=
"keyword">public
</span><span class=
"special">:
</span>
59 <span class=
"identifier">MyObject
</span><span class=
"special">(){}
</span>
60 <span class=
"identifier">MyObject
</span><span class=
"special">(
</span><span class=
"keyword">int
</span> <span class=
"identifier">from
</span><span class=
"special">,
</span> <span class=
"keyword">int
</span> <span class=
"identifier">to
</span><span class=
"special">,
</span> <span class=
"keyword">int
</span> <span class=
"identifier">value
</span><span class=
"special">):
</span> <span class=
"identifier">_from
</span><span class=
"special">(
</span><span class=
"identifier">from
</span><span class=
"special">),
</span> <span class=
"identifier">_to
</span><span class=
"special">(
</span><span class=
"identifier">to
</span><span class=
"special">),
</span> <span class=
"identifier">_value
</span><span class=
"special">(
</span><span class=
"identifier">value
</span><span class=
"special">){}
</span>
61 <span class=
"keyword">int
</span> <span class=
"identifier">from
</span><span class=
"special">()
</span><span class=
"keyword">const
</span> <span class=
"special">{
</span><span class=
"keyword">return
</span> <span class=
"identifier">_from
</span><span class=
"special">;}
</span>
62 <span class=
"keyword">int
</span> <span class=
"identifier">to
</span><span class=
"special">()
</span><span class=
"keyword">const
</span> <span class=
"special">{
</span><span class=
"keyword">return
</span> <span class=
"identifier">_to
</span><span class=
"special">;}
</span>
63 <span class=
"keyword">int
</span> <span class=
"identifier">value
</span><span class=
"special">()
</span><span class=
"keyword">const
</span><span class=
"special">{
</span><span class=
"keyword">return
</span> <span class=
"identifier">_value
</span><span class=
"special">;}
</span>
64 <span class=
"keyword">private
</span><span class=
"special">:
</span>
65 <span class=
"keyword">int
</span> <span class=
"identifier">_from
</span><span class=
"special">;
</span>
66 <span class=
"keyword">int
</span> <span class=
"identifier">_to
</span><span class=
"special">;
</span>
67 <span class=
"keyword">int
</span> <span class=
"identifier">_value
</span><span class=
"special">;
</span>
68 <span class=
"special">};
</span>
70 <span class=
"comment">// ... in order to use the std::transform algorithm to fill
71 </span><span class=
"comment">// interval maps with MyObject data we need a function
72 </span><span class=
"comment">// 'to_segment' that maps an object of type MyObject into
73 </span><span class=
"comment">// the value type to the interval map we want to tranform to ...
74 </span><span class=
"identifier">pair
</span><span class=
"special"><</span><span class=
"identifier">discrete_interval
</span><span class=
"special"><</span><span class=
"keyword">int
</span><span class=
"special">>,
</span> <span class=
"keyword">int
</span><span class=
"special">></span> <span class=
"identifier">to_segment
</span><span class=
"special">(
</span><span class=
"keyword">const
</span> <span class=
"identifier">MyObject
</span><span class=
"special">&</span> <span class=
"identifier">myObj
</span><span class=
"special">)
</span>
75 <span class=
"special">{
</span>
76 <span class=
"keyword">return
</span> <span class=
"identifier">std
</span><span class=
"special">::
</span><span class=
"identifier">pair
</span><span class=
"special"><</span> <span class=
"identifier">discrete_interval
</span><span class=
"special"><</span><span class=
"keyword">int
</span><span class=
"special">>,
</span> <span class=
"keyword">int
</span> <span class=
"special">></span>
77 <span class=
"special">(
</span><span class=
"identifier">discrete_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=
"identifier">myObj
</span><span class=
"special">.
</span><span class=
"identifier">from
</span><span class=
"special">(),
</span> <span class=
"identifier">myObj
</span><span class=
"special">.
</span><span class=
"identifier">to
</span><span class=
"special">()),
</span> <span class=
"identifier">myObj
</span><span class=
"special">.
</span><span class=
"identifier">value
</span><span class=
"special">());
</span>
78 <span class=
"special">}
</span>
80 <span class=
"comment">// ... there may be another function that returns the interval
81 </span><span class=
"comment">// of an object only
82 </span><span class=
"identifier">discrete_interval
</span><span class=
"special"><</span><span class=
"keyword">int
</span><span class=
"special">></span> <span class=
"identifier">to_interval
</span><span class=
"special">(
</span><span class=
"keyword">const
</span> <span class=
"identifier">MyObject
</span><span class=
"special">&</span> <span class=
"identifier">myObj
</span><span class=
"special">)
</span>
83 <span class=
"special">{
</span>
84 <span class=
"keyword">return
</span> <span class=
"identifier">discrete_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=
"identifier">myObj
</span><span class=
"special">.
</span><span class=
"identifier">from
</span><span class=
"special">(),
</span> <span class=
"identifier">myObj
</span><span class=
"special">.
</span><span class=
"identifier">to
</span><span class=
"special">());
</span>
85 <span class=
"special">}
</span>
88 <span class=
"comment">// ... make_object computes a sequence of objects to test.
89 </span><span class=
"identifier">vector
</span><span class=
"special"><</span><span class=
"identifier">MyObject
</span><span class=
"special">></span> <span class=
"identifier">make_objects
</span><span class=
"special">()
</span>
90 <span class=
"special">{
</span>
91 <span class=
"identifier">vector
</span><span class=
"special"><</span><span class=
"identifier">MyObject
</span><span class=
"special">></span> <span class=
"identifier">object_vec
</span><span class=
"special">;
</span>
92 <span class=
"identifier">object_vec
</span><span class=
"special">.
</span><span class=
"identifier">push_back
</span><span class=
"special">(
</span><span class=
"identifier">MyObject
</span><span class=
"special">(
</span><span class=
"number">2</span><span class=
"special">,
</span><span class=
"number">3</span><span class=
"special">,
</span><span class=
"number">1</span><span class=
"special">));
</span>
93 <span class=
"identifier">object_vec
</span><span class=
"special">.
</span><span class=
"identifier">push_back
</span><span class=
"special">(
</span><span class=
"identifier">MyObject
</span><span class=
"special">(
</span><span class=
"number">4</span><span class=
"special">,
</span><span class=
"number">4</span><span class=
"special">,
</span><span class=
"number">1</span><span class=
"special">));
</span>
94 <span class=
"identifier">object_vec
</span><span class=
"special">.
</span><span class=
"identifier">push_back
</span><span class=
"special">(
</span><span class=
"identifier">MyObject
</span><span class=
"special">(
</span><span class=
"number">1</span><span class=
"special">,
</span><span class=
"number">2</span><span class=
"special">,
</span><span class=
"number">1</span><span class=
"special">));
</span>
95 <span class=
"keyword">return
</span> <span class=
"identifier">object_vec
</span><span class=
"special">;
</span>
96 <span class=
"special">}
</span>
98 <span class=
"comment">// ... show_objects displays the sequence of input objects.
99 </span><span class=
"keyword">void
</span> <span class=
"identifier">show_objects
</span><span class=
"special">(
</span><span class=
"keyword">const
</span> <span class=
"identifier">vector
</span><span class=
"special"><</span><span class=
"identifier">MyObject
</span><span class=
"special">>&</span> <span class=
"identifier">objects
</span><span class=
"special">)
</span>
100 <span class=
"special">{
</span>
101 <span class=
"identifier">vector
</span><span class=
"special"><</span><span class=
"identifier">MyObject
</span><span class=
"special">>::
</span><span class=
"identifier">const_iterator
</span> <span class=
"identifier">iter
</span> <span class=
"special">=
</span> <span class=
"identifier">objects
</span><span class=
"special">.
</span><span class=
"identifier">begin
</span><span class=
"special">();
</span>
102 <span class=
"keyword">while
</span><span class=
"special">(
</span><span class=
"identifier">iter
</span> <span class=
"special">!=
</span> <span class=
"identifier">objects
</span><span class=
"special">.
</span><span class=
"identifier">end
</span><span class=
"special">())
</span>
103 <span class=
"special">{
</span>
104 <span class=
"identifier">cout
</span> <span class=
"special"><<</span> <span class=
"string">"(["</span> <span class=
"special"><<</span> <span class=
"identifier">iter
</span><span class=
"special">-
></span><span class=
"identifier">from
</span><span class=
"special">()
</span> <span class=
"special"><<</span> <span class=
"string">","</span> <span class=
"special"><<</span> <span class=
"identifier">iter
</span><span class=
"special">-
></span><span class=
"identifier">to
</span><span class=
"special">()
</span> <span class=
"special"><<</span> <span class=
"string">"],"</span>
105 <span class=
"special"><<</span> <span class=
"identifier">iter
</span><span class=
"special">-
></span><span class=
"identifier">value
</span><span class=
"special">()
</span> <span class=
"special"><<</span> <span class=
"string">")"</span><span class=
"special">;
</span>
106 <span class=
"special">++
</span><span class=
"identifier">iter
</span><span class=
"special">;
</span>
107 <span class=
"special">}
</span>
108 <span class=
"special">}
</span>
111 <span class=
"keyword">void
</span> <span class=
"identifier">std_transform
</span><span class=
"special">()
</span>
112 <span class=
"special">{
</span>
113 <span class=
"comment">// This time we want to transform objects into a splitting interval map:
114 </span> <span class=
"identifier">split_interval_map
</span><span class=
"special"><</span><span class=
"keyword">int
</span><span class=
"special">,
</span><span class=
"keyword">int
</span><span class=
"special">></span> <span class=
"identifier">segmap
</span><span class=
"special">;
</span>
115 <span class=
"identifier">vector
</span><span class=
"special"><</span><span class=
"identifier">MyObject
</span><span class=
"special">></span> <span class=
"identifier">myObjects
</span> <span class=
"special">=
</span> <span class=
"identifier">make_objects
</span><span class=
"special">();
</span>
117 <span class=
"comment">// Display the input
118 </span> <span class=
"identifier">cout
</span> <span class=
"special"><<</span> <span class=
"string">"input sequence: "</span><span class=
"special">;
</span> <span class=
"identifier">show_objects
</span><span class=
"special">(
</span><span class=
"identifier">myObjects
</span><span class=
"special">);
</span> <span class=
"identifier">cout
</span> <span class=
"special"><<</span> <span class=
"string">"\n\n"</span><span class=
"special">;
</span>
120 <span class=
"comment">// Use an icl::inserter to fill the interval map via inserts
121 </span> <span class=
"identifier">std
</span><span class=
"special">::
</span><span class=
"identifier">transform
</span><span class=
"special">(
</span><span class=
"identifier">myObjects
</span><span class=
"special">.
</span><span class=
"identifier">begin
</span><span class=
"special">(),
</span> <span class=
"identifier">myObjects
</span><span class=
"special">.
</span><span class=
"identifier">end
</span><span class=
"special">(),
</span>
122 <span class=
"identifier">icl
</span><span class=
"special">::
</span><span class=
"identifier">inserter
</span><span class=
"special">(
</span><span class=
"identifier">segmap
</span><span class=
"special">,
</span> <span class=
"identifier">segmap
</span><span class=
"special">.
</span><span class=
"identifier">end
</span><span class=
"special">()),
</span>
123 <span class=
"identifier">to_segment
</span><span class=
"special">);
</span>
124 <span class=
"identifier">cout
</span> <span class=
"special"><<</span> <span class=
"string">"icl::inserting: "</span> <span class=
"special"><<</span> <span class=
"identifier">segmap
</span> <span class=
"special"><<</span> <span class=
"identifier">endl
</span><span class=
"special">;
</span>
125 <span class=
"identifier">segmap
</span><span class=
"special">.
</span><span class=
"identifier">clear
</span><span class=
"special">();
</span>
127 <span class=
"comment">// In order to compute aggregation results on associated values, we
128 </span> <span class=
"comment">// usually want to use an icl::adder instead of an std or icl::inserter
129 </span> <span class=
"identifier">std
</span><span class=
"special">::
</span><span class=
"identifier">transform
</span><span class=
"special">(
</span><span class=
"identifier">myObjects
</span><span class=
"special">.
</span><span class=
"identifier">begin
</span><span class=
"special">(),
</span> <span class=
"identifier">myObjects
</span><span class=
"special">.
</span><span class=
"identifier">end
</span><span class=
"special">(),
</span>
130 <span class=
"identifier">icl
</span><span class=
"special">::
</span><span class=
"identifier">adder
</span><span class=
"special">(
</span><span class=
"identifier">segmap
</span><span class=
"special">,
</span> <span class=
"identifier">segmap
</span><span class=
"special">.
</span><span class=
"identifier">end
</span><span class=
"special">()),
</span>
131 <span class=
"identifier">to_segment
</span><span class=
"special">);
</span>
132 <span class=
"identifier">cout
</span> <span class=
"special"><<</span> <span class=
"string">"icl::adding : "</span> <span class=
"special"><<</span> <span class=
"identifier">segmap
</span> <span class=
"special"><<</span> <span class=
"string">"\n\n"</span><span class=
"special">;
</span>
134 <span class=
"identifier">separate_interval_set
</span><span class=
"special"><</span><span class=
"keyword">int
</span><span class=
"special">></span> <span class=
"identifier">segset
</span><span class=
"special">;
</span>
135 <span class=
"identifier">std
</span><span class=
"special">::
</span><span class=
"identifier">transform
</span><span class=
"special">(
</span><span class=
"identifier">myObjects
</span><span class=
"special">.
</span><span class=
"identifier">begin
</span><span class=
"special">(),
</span> <span class=
"identifier">myObjects
</span><span class=
"special">.
</span><span class=
"identifier">end
</span><span class=
"special">(),
</span>
136 <span class=
"identifier">icl
</span><span class=
"special">::
</span><span class=
"identifier">adder
</span> <span class=
"special">(
</span><span class=
"identifier">segset
</span><span class=
"special">,
</span> <span class=
"identifier">segset
</span><span class=
"special">.
</span><span class=
"identifier">end
</span><span class=
"special">()),
</span>
137 <span class=
"comment">// could be a icl::inserter(segset, segset.end()), here: same effect
138 </span> <span class=
"identifier">to_interval
</span><span class=
"special">);
</span>
140 <span class=
"identifier">cout
</span> <span class=
"special"><<</span> <span class=
"string">"Using std::transform to fill a separate_interval_set:\n\n"</span><span class=
"special">;
</span>
141 <span class=
"identifier">cout
</span> <span class=
"special"><<</span> <span class=
"string">"icl::adding : "</span> <span class=
"special"><<</span> <span class=
"identifier">segset
</span> <span class=
"special"><<</span> <span class=
"string">"\n\n"</span><span class=
"special">;
</span>
142 <span class=
"special">}
</span>
145 <span class=
"keyword">int
</span> <span class=
"identifier">main
</span><span class=
"special">()
</span>
146 <span class=
"special">{
</span>
147 <span class=
"identifier">cout
</span> <span class=
"special"><<</span> <span class=
"string">">> Interval Container Library: Example std_transform.cpp <<\n"</span><span class=
"special">;
</span>
148 <span class=
"identifier">cout
</span> <span class=
"special"><<</span> <span class=
"string">"------------------------------------------------------------\n"</span><span class=
"special">;
</span>
149 <span class=
"identifier">cout
</span> <span class=
"special"><<</span> <span class=
"string">"Using std::transform to fill a split_interval_map:\n\n"</span><span class=
"special">;
</span>
151 <span class=
"identifier">std_transform
</span><span class=
"special">();
</span>
152 <span class=
"keyword">return
</span> <span class=
"number">0</span><span class=
"special">;
</span>
153 <span class=
"special">}
</span>
155 <span class=
"comment">// Program output:
156 </span><span class=
"comment">/*----------------------------------------------------------
157 >> Interval Container Library: Example std_transform.cpp
<<
158 ------------------------------------------------------------
159 Using std::transform to fill a split_interval_map:
161 input sequence: ([
2,
3],
1)([
4,
4],
1)([
1,
2],
1)
163 icl::inserting: {([
1,
2)-
>1)([
2,
3]-
>1)([
4,
4]-
>1)}
164 icl::adding : {([
1,
2)-
>1)([
2,
2]-
>2)((
2,
3]-
>1)([
4,
4]-
>1)}
166 Using std::transform to fill a separate_interval_set:
168 icl::adding : {[
1,
3][
4,
4]}
169 ----------------------------------------------------------*/
</span>
176 To get clear about the different behaviors of interval containers in the
177 example, you may want to refer to the section about
<a class=
"link" href=
"../../index.html#boost_icl.introduction.interval_combining_styles" title=
"Interval Combining Styles">interval
178 combining styles
</a> that uses the same data.
181 <table xmlns:
rev=
"http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width=
"100%"><tr>
182 <td align=
"left"></td>
183 <td align=
"right"><div class=
"copyright-footer">Copyright
© 2007 -
2010 Joachim Faulhaber
<br>Copyright
© 1999 -
2006 Cortex Software GmbH
<p>
184 Distributed under the Boost Software License, Version
1.0. (See accompanying
185 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>)
190 <div class=
"spirit-nav">
191 <a accesskey=
"p" href=
"std_copy.html"><img src=
"../../../../../../doc/src/images/prev.png" alt=
"Prev"></a><a accesskey=
"u" href=
"../examples.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=
"custom_interval.html"><img src=
"../../../../../../doc/src/images/next.png" alt=
"Next"></a>