Ticket #4421: seq_first_rest_n.patch

boost/preprocessor/seq/detail/split.hpp

@@ -22 +22 @@
 #    define BOOST_PP_SEQ_SPLIT_D(n, seq) (BOOST_PP_SEQ_SPLIT_ ## n seq)
 # else
 #    define BOOST_PP_SEQ_SPLIT_D(n, seq) (BOOST_PP_SEQ_SPLIT_ ## n ## seq)
+#    define BOOST_PP_SEQ_SPLIT_0_BOOST_PP_EMPTY BOOST_PP_EMPTY, BOOST_PP_EMPTY
 # endif
 #
-# define BOOST_PP_SEQ_SPLIT_1(x) (x),
+# define BOOST_PP_SEQ_SPLIT_0 BOOST_PP_EMPTY,
+# define BOOST_PP_SEQ_SPLIT_1(x) (x) BOOST_PP_EMPTY,
 # define BOOST_PP_SEQ_SPLIT_2(x) (x) BOOST_PP_SEQ_SPLIT_1
 # define BOOST_PP_SEQ_SPLIT_3(x) (x) BOOST_PP_SEQ_SPLIT_2
 # define BOOST_PP_SEQ_SPLIT_4(x) (x) BOOST_PP_SEQ_SPLIT_3

boost/preprocessor/seq/first_n.hpp

@@ -13 +13 @@
 # define BOOST_PREPROCESSOR_SEQ_FIRST_N_HPP
 #
 # include <boost/preprocessor/config/config.hpp>
-# include <boost/preprocessor/control/if.hpp>
+# include <boost/preprocessor/facilities/empty.hpp>
 # include <boost/preprocessor/seq/detail/split.hpp>
-# include <boost/preprocessor/tuple/eat.hpp>
 # include <boost/preprocessor/tuple/elem.hpp>
 #
 # /* BOOST_PP_SEQ_FIRST_N */
 #
 # if ~BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_EDG()
-#    define BOOST_PP_SEQ_FIRST_N(n, seq) BOOST_PP_IF(n, BOOST_PP_TUPLE_ELEM, BOOST_PP_TUPLE_EAT_3)(2, 0, BOOST_PP_SEQ_SPLIT(n, seq (nil)))
+#    define BOOST_PP_SEQ_FIRST_N(n, seq) BOOST_PP_TUPLE_ELEM(2, 0, BOOST_PP_SEQ_SPLIT(n, seq BOOST_PP_EMPTY))()
 # else
 #    define BOOST_PP_SEQ_FIRST_N(n, seq) BOOST_PP_SEQ_FIRST_N_I(n, seq)
-#    define BOOST_PP_SEQ_FIRST_N_I(n, seq) BOOST_PP_IF(n, BOOST_PP_TUPLE_ELEM, BOOST_PP_TUPLE_EAT_3)(2, 0, BOOST_PP_SEQ_SPLIT(n, seq (nil)))
+#    define BOOST_PP_SEQ_FIRST_N_I(n, seq) BOOST_PP_TUPLE_ELEM(2, 0, BOOST_PP_SEQ_SPLIT(n, seq BOOST_PP_EMPTY))()
 # endif
 #
 # endif

boost/preprocessor/seq/rest_n.hpp

@@ -12 +12 @@
 # ifndef BOOST_PREPROCESSOR_SEQ_REST_N_HPP
 # define BOOST_PREPROCESSOR_SEQ_REST_N_HPP
 #
-# include <boost/preprocessor/arithmetic/inc.hpp>
 # include <boost/preprocessor/config/config.hpp>
 # include <boost/preprocessor/facilities/empty.hpp>
 # include <boost/preprocessor/seq/detail/split.hpp>
@@ -21 +20 @@
 # /* BOOST_PP_SEQ_REST_N */
 #
 # if ~BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_EDG()
-#    define BOOST_PP_SEQ_REST_N(n, seq) BOOST_PP_TUPLE_ELEM(2, 1, BOOST_PP_SEQ_SPLIT(BOOST_PP_INC(n), (nil) seq BOOST_PP_EMPTY))()
+#    define BOOST_PP_SEQ_REST_N(n, seq) BOOST_PP_TUPLE_ELEM(2, 1, BOOST_PP_SEQ_SPLIT(n, seq BOOST_PP_EMPTY))()
 # else
 #    define BOOST_PP_SEQ_REST_N(n, seq) BOOST_PP_SEQ_REST_N_I(n, seq)
-#    define BOOST_PP_SEQ_REST_N_I(n, seq) BOOST_PP_TUPLE_ELEM(2, 1, BOOST_PP_SEQ_SPLIT(BOOST_PP_INC(n), (nil) seq BOOST_PP_EMPTY))()
+#    define BOOST_PP_SEQ_REST_N_I(n, seq) BOOST_PP_TUPLE_ELEM(2, 1, BOOST_PP_SEQ_SPLIT(n, seq BOOST_PP_EMPTY))()
 # endif
 #
 # endif