Hello all, Currently BOOST_MPL_ASSERT_MSG cannot be expanded multiple times on the same line because (on GCC and alike) it uses __LINE__ to generate unique IDs. I have to program a macro that makes a bunch of static assertions when it expands so all these assertions made using BOOST_MPL_ASSERT_MSG are on the same line. I used BOOST_MPL_ASSERT_MSG_IMPL to pass the unique ID directly (which is generated by concatenating __LINE__ with the assertion counter which my macro keeps). However, this is not an ideal solution because BOOST_MPL_ASSERT_MSG_IMPL is part of a private API and it could change in the future. Is there any interest in making BOOST_MPL_ASSERT_IMPL part of the public API? (So I can directly pass the unique ID to use. I'd be best if the unique ID is not required to be numeric but just a concatenable token.) I had a similar issue with Boost.Concet's REQUIRES. #define CONTRACT_AUX_MPL_ASSERT_MSG_(counter, condition, message, types) \ /* unfortunately, need to use Boost.MPL implementation detail */ \ /* to pass unique ID (not just __LINE__) so this macro can be expanded */ \ /* multiple times on the same line if with different IDs */ \ BOOST_MPL_ASSERT_MSG_IMPL( \ BOOST_PP_CAT(BOOST_PP_CAT(message, _id_), counter), \ condition, message, types) // PUBLIC // // Allow to expand multiple assert macros on same line (without name clashes). #define CONTRACT_AUX_MPL_ASSERT_MSG(condition, message, types) \ CONTRACT_AUX_MPL_ASSERT_MSG_( \ BOOST_MPL_AUX_PP_COUNTER(), /* uses Boost.MPL impl detail */ \ condition, message, types) Thanks. --Lorenzo -- View this message in context: http://boost.2283326.n4.nabble.com/boost-mpl-ASSERT-and-other-macros-using-u... Sent from the Boost - Dev mailing list archive at Nabble.com.