Avoid evaluating BOOST_PP_SEQ_HEAD when it isn't needed. Fixes #4465.

[SVN r65120]
This commit is contained in:
Steven Watanabe
2010-08-30 02:26:02 +00:00
parent 568f641d8e
commit c776ac0002

View File

@ -26,7 +26,7 @@
BOOST_PP_IF( \
BOOST_PP_DEC(BOOST_PP_SEQ_SIZE(seq)), \
BOOST_PP_SEQ_CAT_I, \
BOOST_PP_SEQ_HEAD(seq) BOOST_PP_TUPLE_EAT_1 \
BOOST_PP_SEQ_HEAD \
)(seq) \
/**/
# define BOOST_PP_SEQ_CAT_I(seq) BOOST_PP_SEQ_FOLD_LEFT(BOOST_PP_SEQ_CAT_O, BOOST_PP_SEQ_HEAD(seq), BOOST_PP_SEQ_TAIL(seq))
@ -39,10 +39,11 @@
# define BOOST_PP_SEQ_CAT_S(s, seq) \
BOOST_PP_IF( \
BOOST_PP_DEC(BOOST_PP_SEQ_SIZE(seq)), \
BOOST_PP_SEQ_CAT_S_I, \
BOOST_PP_SEQ_HEAD(seq) BOOST_PP_TUPLE_EAT_2 \
BOOST_PP_SEQ_CAT_S_I_A, \
BOOST_PP_SEQ_CAT_S_I_B \
)(s, seq) \
/**/
# define BOOST_PP_SEQ_CAT_S_I(s, seq) BOOST_PP_SEQ_FOLD_LEFT_ ## s(BOOST_PP_SEQ_CAT_O, BOOST_PP_SEQ_HEAD(seq), BOOST_PP_SEQ_TAIL(seq))
# define BOOST_PP_SEQ_CAT_S_I_A(s, seq) BOOST_PP_SEQ_FOLD_LEFT_ ## s(BOOST_PP_SEQ_CAT_O, BOOST_PP_SEQ_HEAD(seq), BOOST_PP_SEQ_TAIL(seq))
# define BOOST_PP_SEQ_CAT_S_I_B(s, seq) BOOST_PP_SEQ_HEAD(seq)
#
# endif