On Aug 4, 2015, at 20:32, Alexander Monakov <amonakov@xxxxxxxxx> wrote: > On Tue, 4 Aug 2015, Jonathan Wakely wrote: >> The extern template tells the compiler it doesn't *need* to >> instantiate the template, because it will be explicitly instantiated >> in another translation unit. But that doesn't mean it *must not* >> instantiate it. The compiler can choose to inline the function and in >> that case it will implicitly instantiate it. That should be >> unobservable because the One Definition Rule means that the implicitly >> instantiated definition that gets inlined and the explicitly >> instantiation definition in the other translation unit must be >> identical. The Windows linkage model seems to break that assumption >> ... so I don't know what the right behaviour is. > > In light of that, perhaps it's best to structure code in a way that prevents > implementation of a singleton from being visible in translation units that can > be linked into different libraries. Thanks for pointing this out. I’ll use __attribute__ (noinline) for functions with static variables.
