Disabling try/catch through preprocessor when compiling without exception support was suggested e.g by Robert Ramey in: http://aspn.activestate.com/ASPN/Mail/Message/boost/1799735 Right now there are 3 libraries near review, each using their own set of similar macros: - circular_buffer - indexed_set - serialization The reasons to use macros instead of RAII is convenience and performance. Some compilers (BCB) do not allow try/catch with exceptions disabled so some solution is needed. It would be better to have and use standardized macros in Boost. Example: macros used in indexed_set: #if !defined(BOOST_NO_EXCEPTIONS) # define BOOST_INDEXED_SET_TRY try # define BOOST_INDEXED_SET_CATCH(x) catch(x) # define BOOST_INDEXED_SET_RETHROW throw #else # define BOOST_INDEXED_SET_TRY # define BOOST_INDEXED_SET_CATCH(x) if(0) # define BOOST_INDEXED_SET_RETHROW #endif Compiles w/o warnings on VC6+, BCB gives unreachable code warning (but I'll try to find workaround). /Pavel