John Maddock:
Done, John.
Thanks! The tests for sched_yield and nanosleep now fail as expected on g++/Sun. :-) clock_gettime also fails to link across the board. I think that we ought to fix this by adding -lrt even in <threading>single instead of #undef-ing the feature macros, since these calls aren't technically tied to threads. The pthread_mutex_setattr test also fails; this is, I believe, a symptom of missing pthread support that should be indicated by the absence of BOOST_HAS_PTHREADS. The has_pthreads test doesn't fail because it only checks for pthread_mutex_lock/unlock. It should probably attempt at least a pthread_create. (I also need pthread_mutex_trylock availability for the new shared_ptr tests, but it might be covered by the pthread_create test.)