/usr/include/sigc++-2.0/sigc++/signal.h: In static member function ‘static sigc::internal::signal_emit0<void, sigc::nil>::result_type sigc::internal::signal_emit0<void, sigc::nil>::emit(sigc::internal::signal_impl*)’:
/usr/include/sigc++-2.0/sigc++/signal.h:794:56: error: cast between incompatible function types from ‘sigc::internal::hook’ {aka ‘void* (*)(void*)’} to ‘sigc::internal::signal_emit0<void, sigc::nil>::call_type’ {aka ‘void (*)(sigc::internal::slot_rep*)’} [-Werror=cast-function-type]
           (reinterpret_cast<call_type>(slot.rep_->call_))(slot.rep_);
                                                        ^
/usr/include/sigc++-2.0/sigc++/signal.h: In static member function ‘static sigc::internal::signal_emit0<void, sigc::nil>::result_type sigc::internal::signal_emit0<void, sigc::nil>::emit_reverse(sigc::internal::signal_impl*)’:
/usr/include/sigc++-2.0/sigc++/signal.h:821:55: error: cast between incompatible function types from ‘sigc::internal::hook’ {aka ‘void* (*)(void*)’} to ‘sigc::internal::signal_emit0<void, sigc::nil>::call_type’ {aka ‘void (*)(sigc::internal::slot_rep*)’} [-Werror=cast-function-type]
           (reinterpret_cast<call_type>(it->rep_->call_))(it->rep_);
                                                       ^
cc1plus: all warnings being treated as errors