diff options
Diffstat (limited to 'boost/preprocessor/tuple/elem.hpp')
| -rw-r--r-- | boost/preprocessor/tuple/elem.hpp | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/boost/preprocessor/tuple/elem.hpp b/boost/preprocessor/tuple/elem.hpp index 3eba1c5073..0ee8a3f011 100644 --- a/boost/preprocessor/tuple/elem.hpp +++ b/boost/preprocessor/tuple/elem.hpp @@ -8,7 +8,7 @@ # */ # # /* Revised by Paul Mensonides (2002-2011) */ -# /* Revised by Edward Diener (2011) */ +# /* Revised by Edward Diener (2011,2014) */ # # /* See http://www.boost.org for most recent version. */ # @@ -17,19 +17,29 @@ # # include <boost/preprocessor/cat.hpp> # include <boost/preprocessor/config/config.hpp> +# include <boost/preprocessor/facilities/expand.hpp> # include <boost/preprocessor/facilities/overload.hpp> # include <boost/preprocessor/tuple/rem.hpp> # include <boost/preprocessor/variadic/elem.hpp> +# include <boost/preprocessor/tuple/detail/is_single_return.hpp> # # if BOOST_PP_VARIADICS # if BOOST_PP_VARIADICS_MSVC # define BOOST_PP_TUPLE_ELEM(...) BOOST_PP_TUPLE_ELEM_I(BOOST_PP_OVERLOAD(BOOST_PP_TUPLE_ELEM_O_, __VA_ARGS__), (__VA_ARGS__)) # define BOOST_PP_TUPLE_ELEM_I(m, args) BOOST_PP_TUPLE_ELEM_II(m, args) -# define BOOST_PP_TUPLE_ELEM_II(m, args) BOOST_PP_CAT(m ## args,) +# define BOOST_PP_TUPLE_ELEM_II(m, args) BOOST_PP_CAT(BOOST_PP_EXPAND(m ## args),) +/* + Use BOOST_PP_REM_CAT if it is a single element tuple ( which might be empty ) + else use BOOST_PP_REM. This fixes a VC++ problem with an empty tuple and BOOST_PP_TUPLE_ELEM + functionality. See tuple_elem_bug_test.cxx. +*/ +# define BOOST_PP_TUPLE_ELEM_O_2(n, tuple) \ + BOOST_PP_VARIADIC_ELEM(n, BOOST_PP_TUPLE_IS_SINGLE_RETURN(BOOST_PP_REM_CAT,BOOST_PP_REM,tuple) tuple) \ + /**/ # else # define BOOST_PP_TUPLE_ELEM(...) BOOST_PP_OVERLOAD(BOOST_PP_TUPLE_ELEM_O_, __VA_ARGS__)(__VA_ARGS__) +# define BOOST_PP_TUPLE_ELEM_O_2(n, tuple) BOOST_PP_VARIADIC_ELEM(n, BOOST_PP_REM tuple) # endif -# define BOOST_PP_TUPLE_ELEM_O_2(n, tuple) BOOST_PP_VARIADIC_ELEM(n, BOOST_PP_REM tuple) # define BOOST_PP_TUPLE_ELEM_O_3(size, n, tuple) BOOST_PP_TUPLE_ELEM_O_2(n, tuple) # else # if BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_MSVC() |