namespace boost { namespace lambda { template struct placeholder; template class lambda_functor; namespace detail { } enum {FIRST = 0x01}; template<> struct placeholder {}; typedef const lambda_functor > placeholder1_type; template class lambda_functor : public T { public: typedef T inherited; lambda_functor() { } }; boost::lambda::placeholder1_type free1 = boost::lambda::placeholder1_type(); boost::lambda::placeholder1_type& _1 = free1; using boost::lambda::_1; }; };