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[SVN r12606]
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Vesa Karvonen
2002-01-31 15:36:01 +00:00
parent 2261c57310
commit b9fc39ddd5
134 changed files with 2746 additions and 7072 deletions
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<HTML><HEAD><TITLE>Boost PREPROCESSOR library</TITLE><BODY bgcolor="#FFFFFF">
<a href="index.htm"><IMG height=86 alt="c++boost.gif (8819 bytes)" src="../../../../c++boost.gif" width=277 align=center></a>
<hr>
<H1>#include &lt;<a href="../../../../boost/preprocessor/cat.hpp">boost/preprocessor/cat.hpp</a>&gt;</H1>
<hr>
<H2><a name="BOOST_PP_CAT">#define BOOST_PP_CAT</a>(X,Y)</H2>
<P>Delays the catenation of X and Y.</P>
<P>For example,</P>
<PRE>
#define STATIC_ASSERT(EXPR)\
enum\
{ <a href="cat.htm#BOOST_PP_CAT">BOOST_PP_CAT</a>(static_check_,__LINE__) = (EXPR) ? 1 : -1\
};\
typedef char\
<a href="cat.htm#BOOST_PP_CAT">BOOST_PP_CAT</a>(static_assert_,__LINE__)\
[ <a href="cat.htm#BOOST_PP_CAT">BOOST_PP_CAT</a>(static_check_,__LINE__)\
]
// ...
STATIC_ASSERT(sizeof(int) <= sizeof(long));
</PRE>
<P>expands to:</P>
<PRE>
enum
{ static_check_152 = (sizeof(int) <= sizeof(long)) ? 1 : -1
};
typedef char
static_assert_152
[ static_check_152
];
</PRE>
<P>Using <a href="cat.htm#BOOST_PP_CAT">BOOST_PP_CAT</a>() above lets the PP expand the __LINE__. If the above
code would use the ## operator directly then __LINE__ would not be expanded and
the above would expand to:</P>
<PRE>
enum
{ static_check___LINE__ = (sizeof(int) <= sizeof(long)) ? 1 : -1
};
typedef char
static_assert___LINE__
[ static_check___LINE__
];
</PRE>
<hr>
<H2><a name="BOOST_PREPROCESSOR_CAT">#define BOOST_PREPROCESSOR_CAT</a>(X,Y)</H2>
<P>Obsolete. Use <a href="cat.htm#BOOST_PP_CAT">BOOST_PP_CAT</a>().</P>
<hr>
<p>(C) Copyright Housemarque Oy 2002</p>
<p>Permission to copy, use, modify, sell and distribute this document is granted
provided this copyright notice appears in all copies. This document is provided
"as is" without express or implied warranty, and with no claim as to its suitability
for any purpose.</p>
<p>Generated: <!--webbot bot="Timestamp" s-type="EDITED" s-format="%d %b %Y" startspan --><!--webbot bot="Timestamp" endspan i-checksum="15246" --></p>
</BODY></HTML>