forked from boostorg/preprocessor
71 lines
1.6 KiB
C++
71 lines
1.6 KiB
C++
#ifndef BOOST_PREPROCESSOR_CAT_HPP
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#define BOOST_PREPROCESSOR_CAT_HPP
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/* Copyright (C) 2001
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* Housemarque Oy
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* http://www.housemarque.com
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*
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* Permission to copy, use, modify, sell and distribute this software is
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* granted provided this copyright notice appears in all copies. This
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* software is provided "as is" without express or implied warranty, and
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* with no claim as to its suitability for any purpose.
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*
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* See http://www.boost.org for most recent version.
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*/
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/** <P>Delays the catenation of X and Y.</P>
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<P>For example,</P>
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<PRE>
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#define STATIC_ASSERT(EXPR)\
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enum\
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{ BOOST_PP_CAT(static_check_,__LINE__) = (EXPR) ? 1 : -1\
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};\
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typedef char\
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BOOST_PP_CAT(static_assert_,__LINE__)\
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[ BOOST_PP_CAT(static_check_,__LINE__)\
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]
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// ...
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STATIC_ASSERT(sizeof(int) <= sizeof(long));
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</PRE>
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<P>expands to:</P>
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<PRE>
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enum
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{ static_check_152 = (sizeof(int) <= sizeof(long)) ? 1 : -1
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};
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typedef char
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static_assert_152
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[ static_check_152
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];
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</PRE>
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<P>Using BOOST_PP_CAT() above lets the PP expand the __LINE__. If the above
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code would use the ## operator directly then __LINE__ would not be expanded and
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the above would expand to:</P>
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<PRE>
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enum
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{ static_check___LINE__ = (sizeof(int) <= sizeof(long)) ? 1 : -1
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};
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typedef char
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static_assert___LINE__
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[ static_check___LINE__
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];
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</PRE>
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*/
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#define BOOST_PP_CAT(X,Y) BOOST_PP_CAT_DELAY(X,Y)
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#ifndef DOXYGEN_SHOULD_SKIP_THIS
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#define BOOST_PP_CAT_DELAY(X,Y) BOOST_PP_DO_CAT(X,Y)
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#define BOOST_PP_DO_CAT(X,Y) X##Y
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#endif
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/** <P>Obsolete. Use BOOST_PP_CAT().</P> */
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#define BOOST_PREPROCESSOR_CAT(X,Y) BOOST_PP_CAT(X,Y)
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#endif
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