Module CXX11Traits: vsmc::cxx11::is_union is not correctly implemented. This type traits need compiler support to be implemented. The current behavior is that is_union<T> derives from vsmc::cxx11::false_type for any T. In addition, is_class<T> derives vsmc::cxx11::true_type if the template parameter type is a union, while it should derive from vsmc::cxx11::false_type
Class vsmc::DispatchSourceBase< Type >: A DispachSource object is manually retained when created. It is supposed to be retained by dispatch_source_create according to the documents. But this seems not to be the case in the current implementation (Mac OS X 10.9). The worst case is that a source object is retained one more time than it is released. A simple test example is,
::dispatch_source_t source = ::dispatch_source_create( /* arguments */ );

::dispatch_release(source); // generate error