> From the g++ man pages, -mthreads "Support thread-safe exception handling > on Mingw32" and only defines _MT for Mingw32. Therefore, after threading > support is disabled on line 53 of boost/config/compiler/gcc.hpp, nothing > actually enables it again for a non-Mingw32 cygwin build. Is this the > desired behaviour? (If I removed the check for __CYGWIN__ in gcc.hpp, > everything compiles and the tests seem to run correctly).
No it's not desired - boost/config/suffix.hpp checks for _MT and turns threading support on when it finds it, however, when I build the following program with the -mthreads option I see the #error triggered: #ifndef _MT #error oops #endif Looking further into the specs file it seems that _MT is only defined if you use both -mno-cygwin and -mthreads, cygwin itself appears to no longer set any define in multi-threading mode, so I guess we're back to setting BOOST_HAS_THREADS unconditionally for that compiler :-( John. _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
