1 #ifndef BOOST_PREPROCESSOR_ARITHMETIC_SUB_HPP
2 #define BOOST_PREPROCESSOR_ARITHMETIC_SUB_HPP
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16 #include <boost/preprocessor/dec.hpp>
17 #include <boost/preprocessor/tuple/elem.hpp>
18 #include <boost/preprocessor/while.hpp>
20 /** <p>Expands to the difference of <code>X</code> and <code>Y</code>.</p>
22 <p>Both <code>X</code> and <code>Y</code> must expand to integer literals
23 in the range [0, BOOST_PP_LIMIT_MAG].</p>
25 <p>For example, <code>BOOST_PP_SUB(4,3)</code> expands to <code>1</code> (a
30 <li><a href="../../test/arithmetic_test.cpp">arithmetic_test.cpp</a></li>
33 #define BOOST_PP_SUB(X,Y) BOOST_PP_SUB_D(0,X,Y)
35 /** <p>Can be used inside BOOST_PP_WHILE() (see for an explanation of the D parameter).</p> */
36 #define BOOST_PP_SUB_D(D,X,Y) BOOST_PP_TUPLE_ELEM(2,0,BOOST_PP_WHILE##D(BOOST_PP_SUB_C,BOOST_PP_SUB_F,(X,Y)))
38 #define BOOST_PP_SUB_C(D,RC) BOOST_PP_TUPLE_ELEM(2,1,RC)
39 #define BOOST_PP_SUB_F(D,RC) (BOOST_PP_DEC(BOOST_PP_TUPLE_ELEM(2,0,RC)),BOOST_PP_DEC(BOOST_PP_TUPLE_ELEM(2,1,RC)))