[boost] Portable test_and_set, please...

Hi all, I see some atomic operations in atomic_count.hpp (usable only by the atomic_count class unfortunately, and not directly) for incrementing and decrementing, but the most important atomic operation seems to be missing: the test_and_set. Without that one it's not possible to create lockfree algorithms in MT. Also, atomic incrementing, decrementing etc. can be performed having the test_and_set but not vice versa. Would anybody please make a wrapper for that? On Windows it's the InterlockedCompareExchange, on Gcc and Linux I think they are called __test_and_set and atomic_test_and_set respectively. I don't know if they would better go in the Boost.Threads or in the atomic_something header files... Thanks