summaryrefslogtreecommitdiff
path: root/libs/preprocessor/doc/ref/include_self.html
blob: ce13c3317e8f1b281220e4704fc4ec278b141f82 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
<html>
<head>
	<title>BOOST_PP_INCLUDE_SELF</title>
	<link rel="stylesheet" type="text/css" href="../styles.css">
</head>
<body>
	<div style="margin-left:  0px;">
		The <b>BOOST_PP_INCLUDE_SELF</b> macro includes a file indirectly.
	</div>
	<h4>Usage</h4>
		<div class="code">
			#include <b>BOOST_PP_INCLUDE_SELF</b>()
		</div>
	<h4>Arguments</h4>
		<dl>
			<dt>filename</dt>
			<dd>
				A quoted or angle-bracketed filename to be included by <b>BOOST_PP_INCLUDE_SELF</b>.
			</dd>
		</dl>
	<h4>Remarks</h4>
		<div>
			<b>BOOST_PP_INDIRECT_SELF</b> must be defined prior to using this macro.
		</div>
		<div>
			Most preprocessors will not allow a file to directly include itself--even when the file protects itself from such a scenario.&nbsp;
			This macro, in combination with <b>BOOST_PP_INDIRECT_SELF</b> allows a file to include itself indirectly.
		</div>
		<div>
			While <b>BOOST_PP_INDIRECT_SELF</b> is being included, <b>BOOST_PP_INCLUDE_SELF</b> defines the macro <b>BOOST_PP_IS_SELFISH</b> to <i>1</i>.&nbsp;
			When it returns from the inclusion, <b>BOOST_PP_IS_SELFISH</b> is undefined.
		</div>
	<h4>See Also</h4>
		<ul>
			<li><a href="indirect_self.html">BOOST_PP_INDIRECT_SELF</a></li>
			<li><a href="is_selfish.html">BOOST_PP_IS_SELFISH</a></li>
		</ul>
	<h4>Requirements</h4>
		<div>
			<b>Header:</b> &nbsp;<a href="../headers/iteration/self.html">&lt;boost/preprocessor/iteration/self.hpp&gt;</a>
		</div>
	<h4>Sample Code</h4>
<div><pre>
// file.h
#if !<a href="is_selfish.html">BOOST_PP_IS_SELFISH</a>

   #ifndef FILE_H_
   #define FILE_H_

   #include &lt;<a href="../headers/iteration/self.html">boost/preprocessor/iteration/self.hpp</a>&gt;

   #define NAME X
   struct NAME {
      // ...
      #define <a href="indirect_self.html">BOOST_PP_INDIRECT_SELF</a> "file.h"
      #include <a href="include_self.html">BOOST_PP_INCLUDE_SELF</a>()
   };

   #define NAME Y
   struct NAME {
      // ...
      #define <a href="indirect_self.html">BOOST_PP_INDIRECT_SELF</a> "file.h"
      #include <a href="include_self.html">BOOST_PP_INCLUDE_SELF</a>()
   };

   #define NAME Z
   struct NAME {
      // ...
      #define <a href="indirect_self.html">BOOST_PP_INDIRECT_SELF</a> "file.h"
      #include <a href="include_self.html">BOOST_PP_INCLUDE_SELF</a>()
   };

   #endif

#else

      inline bool validate(NAME* p) {
         return true;
      }

      template&lt;class T&gt; bool validate(T* p) {
         return dynamic_cast&lt;NAME*&gt;(p);
      }

   #undef NAME

#endif
</pre></div>
	<hr size="1">
	<div style="margin-left: 0px;">
		<i>© Copyright <a href="http://www.housemarque.com" target="_top">Housemarque Oy</a> 2002</i>
		</br><i>© Copyright Paul Mensonides 2002</i>
	</div>
	<div style="margin-left: 0px;">
		<p><small>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">www.boost.org/LICENSE_1_0.txt</a>)</small></p>
	</div>
</body>
</html>