tuple functionality will be divided into multiple headers

[SVN r12293]

include/boost/preprocessor/tuple/elem.hpp

@@ -0,0 +1,105 @@
+#ifndef BOOST_PREPROCESSOR_TUPLE_ELEM_HPP
+#define BOOST_PREPROCESSOR_TUPLE_ELEM_HPP
+
+// Copyright (C) 2001
+// Housemarque Oy
+// http://www.housemarque.com
+//
+// Permission to copy, use, modify, sell and distribute this software is
+// granted provided this copyright notice appears in all copies. This
+// software is provided "as is" without express or implied warranty, and
+// with no claim as to its suitability for any purpose.
+
+// See http://www.boost.org for most recent version.
+
+/*! \file
+
+<a href="../../../../boost/preprocessor/tuple/elem.hpp">Click here to see the header.</a>
+*/
+
+#include <boost/preprocessor/identity.hpp>
+
+//! Expands to the I:th element of an N-tuple.
+/*!
+Tuples can be used for representing structured data.
+
+Examples of tuples:
+
+<PRE>\verbatim
+  2-tuple: (A, B)
+  3-tuple: (1, 2, 3)
+  4-tuple: (A B C, D, EF, 34)
+\endverbatim</PRE>
+
+Example:
+
+<PRE>\verbatim
+  BOOST_PP_TUPLE_ELEM(2,1,(A,B))
+\endverbatim</PRE>
+
+The above expands to B.
+
+See also BOOST_PP_LIMIT_TUPLE.
+*/
+#define BOOST_PP_TUPLE_ELEM(N,I,T) BOOST_PP_TUPLE_ELEM_DELAY(N,I,T)
+
+#ifndef DOXYGEN_SHOULD_SKIP_THIS
+#if !defined(BOOST_NO_COMPILER_CONFIG) && defined(__MWERKS__) && __MWERKS__ <= 0x2406
+// This is a workaround for a CodeWarrior PP bug. Strictly speaking
+// this workaround invokes undefined behavior, but it works as desired.
+#  define BOOST_PP_TUPLE_ELEM_DELAY(N,I,T) BOOST_PP_TUPLE##N##_ELEM##I##T
+#else
+#  define BOOST_PP_TUPLE_ELEM_DELAY(N,I,T) BOOST_PP_IDENTITY(BOOST_PP_TUPLE##N##_ELEM##I T)()
+#endif
+
+// NOTE: TUPLE_ELEM can be implemented in O(N*N) space and O(N) time instead
+// of O(N*N*N) space and O(1) time. The current trade-off seems better.
+
+#define BOOST_PP_TUPLE1_ELEM0(A) A
+
+#define BOOST_PP_TUPLE2_ELEM0(A,B) A
+#define BOOST_PP_TUPLE2_ELEM1(A,B) B
+
+#define BOOST_PP_TUPLE3_ELEM0(A,B,C) A
+#define BOOST_PP_TUPLE3_ELEM1(A,B,C) B
+#define BOOST_PP_TUPLE3_ELEM2(A,B,C) C
+
+#define BOOST_PP_TUPLE4_ELEM0(A,B,C,D) A
+#define BOOST_PP_TUPLE4_ELEM1(A,B,C,D) B
+#define BOOST_PP_TUPLE4_ELEM2(A,B,C,D) C
+#define BOOST_PP_TUPLE4_ELEM3(A,B,C,D) D
+
+#define BOOST_PP_TUPLE5_ELEM0(A,B,C,D,E) A
+#define BOOST_PP_TUPLE5_ELEM1(A,B,C,D,E) B
+#define BOOST_PP_TUPLE5_ELEM2(A,B,C,D,E) C
+#define BOOST_PP_TUPLE5_ELEM3(A,B,C,D,E) D
+#define BOOST_PP_TUPLE5_ELEM4(A,B,C,D,E) E
+
+#define BOOST_PP_TUPLE6_ELEM0(A,B,C,D,E,F) A
+#define BOOST_PP_TUPLE6_ELEM1(A,B,C,D,E,F) B
+#define BOOST_PP_TUPLE6_ELEM2(A,B,C,D,E,F) C
+#define BOOST_PP_TUPLE6_ELEM3(A,B,C,D,E,F) D
+#define BOOST_PP_TUPLE6_ELEM4(A,B,C,D,E,F) E
+#define BOOST_PP_TUPLE6_ELEM5(A,B,C,D,E,F) F
+
+#define BOOST_PP_TUPLE7_ELEM0(A,B,C,D,E,F,G) A
+#define BOOST_PP_TUPLE7_ELEM1(A,B,C,D,E,F,G) B
+#define BOOST_PP_TUPLE7_ELEM2(A,B,C,D,E,F,G) C
+#define BOOST_PP_TUPLE7_ELEM3(A,B,C,D,E,F,G) D
+#define BOOST_PP_TUPLE7_ELEM4(A,B,C,D,E,F,G) E
+#define BOOST_PP_TUPLE7_ELEM5(A,B,C,D,E,F,G) F
+#define BOOST_PP_TUPLE7_ELEM6(A,B,C,D,E,F,G) G
+
+#define BOOST_PP_TUPLE8_ELEM0(A,B,C,D,E,F,G,H) A
+#define BOOST_PP_TUPLE8_ELEM1(A,B,C,D,E,F,G,H) B
+#define BOOST_PP_TUPLE8_ELEM2(A,B,C,D,E,F,G,H) C
+#define BOOST_PP_TUPLE8_ELEM3(A,B,C,D,E,F,G,H) D
+#define BOOST_PP_TUPLE8_ELEM4(A,B,C,D,E,F,G,H) E
+#define BOOST_PP_TUPLE8_ELEM5(A,B,C,D,E,F,G,H) F
+#define BOOST_PP_TUPLE8_ELEM6(A,B,C,D,E,F,G,H) G
+#define BOOST_PP_TUPLE8_ELEM7(A,B,C,D,E,F,G,H) H
+#endif
+
+//! Obsolete. Use BOOST_PP_TUPLE_ELEM().
+#define BOOST_PREPROCESSOR_TUPLE_ELEM(N,I,T) BOOST_PP_TUPLE_ELEM(N,I,T)
+#endif