To mirror another message I sent regarding aligned_storage, I like the idea of making this library a part of boost, but I don't like the idea of having countless dependencies upon boost.
Just going to jump out from lurk mode for a second here, hope you don't mind me butting in;) I really don't get what the problem with dependencies on boost is. The whole point of boost as I see it is a big repository of well developed and proven portable code, subverting this just brings all the associated maintenence problems of having effectively duplicated code. If someone installs the boost libraries they have no problems with dependencies as they have all the applicable code. If you want fine grained control for people who really do not want / have space for additional boost libraries being linked in then specifying a preprocessor directive at build time would seem appropriate. I would expect a boost library to support the other boost libraries as well out of the box if natural to do so, I would not like at all having to write extra code to get a multi-thread safe singleton. I don't know about gcc but I do know the vc dead code optimiser is very good and aggressive (far too much so under certain circumstances, just to check at the end is a small test) so linking to a library where most code is unused just doesn't bother me, maybe someone else can say how good gcc and metrowerks are in this respect. And anyway whats few k between friends these days for good solid and reliable code;) Maybe I'm missing some other reason to avoid the dependancy? Anyhow just my 2 aussie cents, thanks for the work your putting in, I would love to see this enter boost. cheers martin ------------------------------------------------------------------ Code is at bottom, the difference with vc is only 12k from a 923k library on disk using the boost policy and nothing at all if the policy isn't used but the library is still linked. It just doesn't seem worth putting any effort into avoiding boost (threads at least) if executable size is a problem. Results -------- (vc7.1) thread lib size : 923kb no boost at all : 76kb boost policy defined but not used : 76kb boost policy defined and used : 88kb (mingw-1.32.0rc1 - gcc 3.4.2) thread lib size : 335kb no boost at all : 474,875kb boost policy defined but not used : 474,875kb boost policy defined and used : 527,569kb ------------------------------------------------------------------- #define BOOST_LIB_DIAGNOSTIC #define USE_BOOST #define DEFINE_BOOST_BUT_DONT_USE #include <iostream> #ifdef USE_BOOST #include <boost/thread/mutex.hpp> #endif template<class LockType, class LockerType> struct LockerTraits { typedef LockType Lock; typedef LockerType Locker; }; struct NullLocker { NullLocker(int) {} }; typedef LockerTraits<int, NullLocker> NullLockPolicy; #if defined(USE_BOOST) && !defined(DEFINE_BOOST_BUT_DONT_USE) typedef LockerTraits<boost::mutex, boost::mutex::scoped_lock> BoostLockPolicy; #endif template<class Locker> struct Fish { void print() { typename Locker::Locker lock(m_lock); std::cout << "hello" << std::endl; } typename Locker::Lock m_lock; }; int main(int argc, char* argv[]) { #if defined(USE_BOOST) && !defined(DEFINE_BOOST_BUT_DONT_USE) Fish<BoostLockPolicy> fishy; #else Fish<NullLockPolicy> fishy; #endif fishy.print(); return 0; }