Compilation problem sigc++/gtkmm in own namespaces

Having our own namespaces in a project, we would like to include a GUI using gtkmm.

// in a header file:
namespace project
{ 
    // namespace "gui" is declared elsewhere    
    class gui::Config : Gtk::Window
    {
        protected:
            Config();

        private:
            // various Gtk::Widget objects

            void connect_signals();

    };
} 

It all works until i try to implement this method:

void Config::connect_signals()
{
    m_notebook.signal_switch_page().connect(sigc::mem_fun(*this,&Config::on_notebook_switch_page));
    m_button_save.signal_clicked().connect(sigc::mem_fun(*this,&Config::on_button_clicked_save));
    m_button_close.signal_clicked().connect(sigc::mem_fun(*this,&Config::on_button_clicked_close));
}

We are then compiling Config.cpp using pkg-config --cflags gtkmm-2.4 开发者_如何学运维and pkg-config --libs gtkmm-2.4.

The compiler finally throws the following message:

In file included from /usr/include/sigc++-2.0/sigc++/signal_base.h:29:0,
         from /usr/include/sigc++-2.0/sigc++/signal.h:8,
         from /usr/include/sigc++-2.0/sigc++/sigc++.h:23,
         from /usr/include/glibmm-2.4/glibmm/signalproxy.h:13,
         from /usr/include/glibmm-2.4/glibmm/objectbase.h:23,
         from /usr/include/glibmm-2.4/glibmm/wrap.h:26,
         from /usr/include/glibmm-2.4/glibmm/containerhandle_shared.h:25,
         from /usr/include/glibmm-2.4/glibmm/arrayhandle.h:23,
         from /usr/include/glibmm-2.4/glibmm.h:83,
         from /usr/include/gtkmm-2.4/gtkmm.h:87,
         from include/libproject.h:12,
         from include/gui/Config.h:4,
         from src/gui/Config.cpp:1:
/usr/include/sigc++-2.0/sigc++/type_traits.h: In instantiation of ‘const bool sigc::is_base_and_derived<sigc::trackable, project::gui::Config>::value’:
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h:1922:26:   instantiated from ‘sigc::bound_mem_functor2<void, project::gui::Config, _GtkNotebookPage*, unsigned int>’
src/gui/Config.cpp:70:94:   instantiated from here
/usr/include/sigc++-2.0/sigc++/type_traits.h:132:16: error: ‘sigc::trackable’ is an inaccessible base of ‘project::gui::Config’
In file included from /usr/include/sigc++-2.0/sigc++/adaptors/adaptor_trait.h:9:0,
         from /usr/include/sigc++-2.0/sigc++/functors/slot.h:7,
         from /usr/include/sigc++-2.0/sigc++/signal_base.h:31,
         from /usr/include/sigc++-2.0/sigc++/signal.h:8,
         from /usr/include/sigc++-2.0/sigc++/sigc++.h:23,
         from /usr/include/glibmm-2.4/glibmm/signalproxy.h:13,
         from /usr/include/glibmm-2.4/glibmm/objectbase.h:23,
         from /usr/include/glibmm-2.4/glibmm/wrap.h:26,
         from /usr/include/glibmm-2.4/glibmm/containerhandle_shared.h:25,
         from /usr/include/glibmm-2.4/glibmm/arrayhandle.h:23,
         from /usr/include/glibmm-2.4/glibmm.h:83,
         from /usr/include/gtkmm-2.4/gtkmm.h:87,
         from include/libproject.h:12,
         from include/gui/Config.h:4,
         from src/gui/Config.cpp:1:
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h: In instantiation of ‘sigc::bound_mem_functor2<void, project::gui::Config, _GtkNotebookPage*, unsigned int>’:
src/gui/Config.cpp:70:94:   instantiated from here
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h:1922:26: error: ‘sigc::is_base_and_derived<sigc::trackable, project::gui::Config>::value’ is not a valid template argument for type ‘bool’ because it is a non-constant expression
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h: In instantiation of ‘sigc::bound_mem_functor0<void, project::gui::Config>’:
src/gui/Config.cpp:72:95:   instantiated from here
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h:1792:26: error: ‘sigc::is_base_and_derived<sigc::trackable, project::gui::Config>::value’ is not a valid template argument for type ‘bool’ because it is a non-constant expression
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h: In constructor ‘sigc::bound_mem_functor2<T_return, T_obj, T_arg1, T_arg2>::bound_mem_functor2(T_obj&, sigc::bound_mem_functor2<T_return, T_obj, T_arg1, T_arg2>::function_type) [with T_return = void, T_obj = project::gui::Config, T_arg1 = _GtkNotebookPage*, T_arg2 = unsigned int, sigc::bound_mem_functor2<T_return, T_obj, T_arg1, T_arg2>::function_type = void (project::gui::Config::*)(_GtkNotebookPage*, unsigned int)]’:
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h:5501:77:   instantiated from ‘sigc::bound_mem_functor2<T_return, T_obj, T_arg1, T_arg2> sigc::mem_fun(T_obj&, T_return (T_obj2::*)(T_arg1, T_arg2)) [with T_arg1 = _GtkNotebookPage*, T_arg2 = unsigned int, T_return = void, T_obj = project::gui::Config, T_obj2 = project::gui::Config]’
src/gui/Config.cpp:70:94:   instantiated from here
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h:1908:18: error: using invalid field ‘sigc::bound_mem_functor2<T_return, T_obj, T_arg1, T_arg2>::obj_’
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h: In constructor ‘sigc::bound_mem_functor0<T_return, T_obj>::bound_mem_functor0(T_obj&, sigc::bound_mem_functor0<T_return, T_obj>::function_type) [with T_return = void, T_obj = project::gui::Config, sigc::bound_mem_functor0<T_return, T_obj>::function_type = void (project::gui::Config::*)()]’:
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h:5453:61:   instantiated from ‘sigc::bound_mem_functor0<T_return, T_obj> sigc::mem_fun(T_obj&, T_return (T_obj2::*)()) [with T_return = void, T_obj = project::gui::Config, T_obj2 = project::gui::Config]’
src/gui/Config.cpp:72:95:   instantiated from here
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h:1780:18: error: using invalid field ‘sigc::bound_mem_functor0<T_return, T_obj>::obj_’
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h: In function ‘void sigc::visit_each(const T_action&, const sigc::bound_mem_functor2<T_return, T_obj, T_arg1, T_arg2>&) [with T_action = sigc::internal::limit_derived_target<sigc::trackable*, sigc::internal::slot_do_bind>, T_return = void, T_obj = project::gui::Config, T_arg1 = _GtkNotebookPage*, T_arg2 = unsigned int]’:
/usr/include/sigc++-2.0/sigc++/adaptors/adaptor_trait.h:267:3:   instantiated from ‘void sigc::visit_each(const T_action&, const sigc::adaptor_functor<T_functor>&) [with T_action = sigc::internal::limit_derived_target<sigc::trackable*, sigc::internal::slot_do_bind>, T_functor = sigc::bound_mem_functor2<void, project::gui::Config, _GtkNotebookPage*, unsigned int>]’
/usr/include/sigc++-2.0/sigc++/visit_each.h:170:3:   instantiated from ‘void sigc::visit_each_type(const T_action&, const T_functor&) [with T_type = sigc::trackable*, T_action = sigc::internal::slot_do_bind, T_functor = sigc::adaptor_functor<sigc::bound_mem_functor2<void, project::gui::Config, _GtkNotebookPage*, unsigned int> >]’
/usr/include/sigc++-2.0/sigc++/functors/slot.h:39:7:   instantiated from ‘sigc::internal::typed_slot_rep<T_functor>::typed_slot_rep(const T_functor&) [with T_functor = sigc::bound_mem_functor2<void, project::gui::Config, _GtkNotebookPage*, unsigned int>]’
/usr/include/sigc++-2.0/sigc++/functors/slot.h:604:65:   instantiated from ‘sigc::slot2<T_return, T_arg1, T_arg2>::slot2(const T_functor&) [with T_functor = sigc::bound_mem_functor2<void, project::gui::Config, _GtkNotebookPage*, unsigned int>, T_return = void, T_arg1 = _GtkNotebookPage*, T_arg2 = unsigned int]’
/usr/include/sigc++-2.0/sigc++/functors/slot.h:1184:26:   instantiated from ‘sigc::slot<T_return, T_arg1, T_arg2, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil>::slot(const T_functor&) [with T_functor = sigc::bound_mem_functor2<void, project::gui::Config, _GtkNotebookPage*, unsigned int>, T_return = void, T_arg1 = _GtkNotebookPage*, T_arg2 = unsigned int]’
src/gui/Config.cpp:70:95:   instantiated from here
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h:1936:3: error: ‘const class sigc::bound_mem_functor2<void, project::gui::Config, _GtkNotebookPage*, unsigned int>’ has no member named ‘obj_’
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h: In member function ‘T_return sigc::bound_mem_functor2<T_return, T_obj, T_arg1, T_arg2>::operator()(typename sigc::type_trait<T_arg3>::take, typename sigc::type_trait<T_arg4>::take) const [with T_return = void, T_obj = project::gui::Config, T_arg1 = _GtkNotebookPage*, T_arg2 = unsigned int, typename sigc::type_trait<T_arg3>::take = _GtkNotebookPage* const&, typename sigc::type_trait<T_arg4>::take = const unsigned int&]’:
/usr/include/sigc++-2.0/sigc++/adaptors/adaptor_trait.h:103:39:   instantiated from ‘typename sigc::adaptor_functor<T_functor>::deduce_result_type<T_arg1, T_arg2>::type sigc::adaptor_functor<T_functor>::operator()(T_arg1, T_arg2) const [with T_arg1 = _GtkNotebookPage* const&, T_arg2 = const unsigned int&, T_functor = sigc::bound_mem_functor2<void, project::gui::Config, _GtkNotebookPage*, unsigned int>, typename sigc::adaptor_functor<T_functor>::deduce_result_type<T_arg1, T_arg2>::type = void]’
/usr/include/sigc++-2.0/sigc++/functors/slot.h:173:25:   instantiated from ‘static T_return sigc::internal::slot_call2<T_functor, T_return, T_arg1, T_arg2>::call_it(sigc::internal::slot_rep*, typename sigc::type_trait<T_arg3>::take, typename sigc::type_trait<T_arg4>::take) [with T_functor = sigc::bound_mem_functor2<void, project::gui::Config, _GtkNotebookPage*, unsigned int>, T_return = void, T_arg1 = _GtkNotebookPage*, T_arg2 = unsigned int, typename sigc::type_trait<T_arg3>::take = _GtkNotebookPage* const&, typename sigc::type_trait<T_arg4>::take = const unsigned int&]’
/usr/include/sigc++-2.0/sigc++/functors/slot.h:180:45:   instantiated from ‘static void* (* sigc::internal::slot_call2<T_functor, T_return, T_arg1, T_arg2>::address())(void*) [with T_functor = sigc::bound_mem_functor2<void, project::gui::Config, _GtkNotebookPage*, unsigned int>, T_return = void, T_arg1 = _GtkNotebookPage*, T_arg2 = unsigned int, void* (*)(void*) = void* (*)(void*)]’
/usr/include/sigc++-2.0/sigc++/functors/slot.h:607:7:   instantiated from ‘sigc::slot2<T_return, T_arg1, T_arg2>::slot2(const T_functor&) [with T_functor = sigc::bound_mem_functor2<void, project::gui::Config, _GtkNotebookPage*, unsigned int>, T_return = void, T_arg1 = _GtkNotebookPage*, T_arg2 = unsigned int]’
/usr/include/sigc++-2.0/sigc++/functors/slot.h:1184:26:   instantiated from ‘sigc::slot<T_return, T_arg1, T_arg2, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil>::slot(const T_functor&) [with T_functor = sigc::bound_mem_functor2<void, project::gui::Config, _GtkNotebookPage*, unsigned int>, T_return = void, T_arg1 = _GtkNotebookPage*, T_arg2 = unsigned int]’
src/gui/Config.cpp:70:95:   instantiated from here
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h:1917:61: error: using invalid field ‘sigc::bound_mem_functor2<T_return, T_obj, T_arg1, T_arg2>::obj_’
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h:1917:61: error: return-statement with a value, in function returning 'void'
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h: In function ‘void sigc::visit_each(const T_action&, const sigc::bound_mem_functor0<T_return, T_obj>&) [with T_action = sigc::internal::limit_derived_target<sigc::trackable*, sigc::internal::slot_do_bind>, T_return = void, T_obj = project::gui::Config]’:
/usr/include/sigc++-2.0/sigc++/adaptors/adaptor_trait.h:267:3:   instantiated from ‘void sigc::visit_each(const T_action&, const sigc::adaptor_functor<T_functor>&) [with T_action = sigc::internal::limit_derived_target<sigc::trackable*, sigc::internal::slot_do_bind>, T_functor = sigc::bound_mem_functor0<void, project::gui::Config>]’
/usr/include/sigc++-2.0/sigc++/visit_each.h:170:3:   instantiated from ‘void sigc::visit_each_type(const T_action&, const T_functor&) [with T_type = sigc::trackable*, T_action = sigc::internal::slot_do_bind, T_functor = sigc::adaptor_functor<sigc::bound_mem_functor0<void, project::gui::Config> >]’
/usr/include/sigc++-2.0/sigc++/functors/slot.h:39:7:   instantiated from ‘sigc::internal::typed_slot_rep<T_functor>::typed_slot_rep(const T_functor&) [with T_functor = sigc::bound_mem_functor0<void, project::gui::Config>]’
/usr/include/sigc++-2.0/sigc++/functors/slot.h:451:65:   instantiated from ‘sigc::slot0<T_return>::slot0(const T_functor&) [with T_functor = sigc::bound_mem_functor0<void, project::gui::Config>, T_return = void]’
/usr/include/sigc++-2.0/sigc++/functors/slot.h:1130:26:   instantiated from ‘sigc::slot<T_return, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil>::slot(const T_functor&) [with T_functor = sigc::bound_mem_functor0<void, project::gui::Config>, T_return = void]’
src/gui/Config.cpp:72:96:   instantiated from here
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h:1806:3: error: ‘const class sigc::bound_mem_functor0<void, project::gui::Config>’ has no member named ‘obj_’
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h: In member function ‘T_return sigc::bound_mem_functor0<T_return, T_obj>::operator()() const [with T_return = void, T_obj = project::gui::Config]’:
/usr/include/sigc++-2.0/sigc++/adaptors/adaptor_trait.h:251:21:   instantiated from ‘sigc::adaptor_functor<T_functor>::result_type sigc::adaptor_functor<T_functor>::operator()() const [with T_functor = sigc::bound_mem_functor0<void, project::gui::Config>, sigc::adaptor_functor<T_functor>::result_type = void]’
/usr/include/sigc++-2.0/sigc++/functors/slot.h:103:36:   instantiated from ‘static T_return sigc::internal::slot_call0<T_functor, T_return>::call_it(sigc::internal::slot_rep*) [with T_functor = sigc::bound_mem_functor0<void, project::gui::Config>, T_return = void]’
/usr/include/sigc++-2.0/sigc++/functors/slot.h:110:45:   instantiated from ‘static void* (* sigc::internal::slot_call0<T_functor, T_return>::address())(void*) [with T_functor = sigc::bound_mem_functor0<void, project::gui::Config>, T_return = void, void* (*)(void*) = void* (*)(void*)]’
/usr/include/sigc++-2.0/sigc++/functors/slot.h:454:7:   instantiated from ‘sigc::slot0<T_return>::slot0(const T_functor&) [with T_functor = sigc::bound_mem_functor0<void, project::gui::Config>, T_return = void]’
/usr/include/sigc++-2.0/sigc++/functors/slot.h:1130:26:   instantiated from ‘sigc::slot<T_return, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil>::slot(const T_functor&) [with T_functor = sigc::bound_mem_functor0<void, project::gui::Config>, T_return = void]’
src/gui/Config.cpp:72:96:   instantiated from here
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h:1787:49: error: using invalid field ‘sigc::bound_mem_functor0<T_return, T_obj>::obj_’
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h:1787:49: error: return-statement with a value, in function returning 'void'
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h: In function ‘void sigc::visit_each(const T_action&, const sigc::bound_mem_functor2<T_return, T_obj, T_arg1, T_arg2>&) [with T_action = sigc::internal::limit_derived_target<sigc::trackable*, sigc::internal::slot_do_unbind>, T_return = void, T_obj = project::gui::Config, T_arg1 = _GtkNotebookPage*, T_arg2 = unsigned int]’:
/usr/include/sigc++-2.0/sigc++/adaptors/adaptor_trait.h:267:3:   instantiated from ‘void sigc::visit_each(const T_action&, const sigc::adaptor_functor<T_functor>&) [with T_action = sigc::internal::limit_derived_target<sigc::trackable*, sigc::internal::slot_do_unbind>, T_functor = sigc::bound_mem_functor2<void, project::gui::Config, _GtkNotebookPage*, unsigned int>]’
/usr/include/sigc++-2.0/sigc++/visit_each.h:170:3:   instantiated from ‘void sigc::visit_each_type(const T_action&, const T_functor&) [with T_type = sigc::trackable*, T_action = sigc::internal::slot_do_unbind, T_functor = sigc::adaptor_functor<sigc::bound_mem_functor2<void, project::gui::Config, _GtkNotebookPage*, unsigned int> >]’
/usr/include/sigc++-2.0/sigc++/functors/slot.h:60:7:   instantiated from ‘static void* sigc::internal::typed_slot_rep<T_functor>::destroy(void*) [with T_functor = sigc::bound_mem_functor2<void, project::gui::Config, _GtkNotebookPage*, unsigned int>]’
/usr/include/sigc++-2.0/sigc++/functors/slot.h:38:52:   instantiated from ‘sigc::internal::typed_slot_rep<T_functor>::typed_slot_rep(const T_functor&) [with T_functor = sigc::bound_mem_functor2<void, project::gui::Config, _GtkNotebookPage*, unsigned int>]’
/usr/include/sigc++-2.0/sigc++/functors/slot.h:604:65:   instantiated from ‘sigc::slot2<T_return, T_arg1, T_arg2>::slot2(const T_functor&) [with T_functor = sigc::bound_mem_functor2<void, project::gui::Config, _GtkNotebookPage*, unsigned int>, T_return = void, T_arg1 = _GtkNotebookPage*, T_arg2 = unsigned int]’
/usr/include/sigc++-2.0/sigc++/functors/slot.h:1184:26:   instantiated from ‘sigc::slot<T_return, T_arg1, T_arg2, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil>::slot(const T_functor&) [with T_functor = sigc::bound_mem_functor2<void, project::gui::Config, _GtkNotebookPage*, unsigned int>, T_return = void, T_arg1 = _GtkNotebookPage*, T_arg2 = unsigned int]’
src/gui/Config.cpp:70:95:   instantiated from here
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h:1936:3: error: ‘const class sigc::bound_mem_functor2<void, project::gui::Config, _GtkNotebookPage*, unsigned int>’ has no member named ‘obj_’
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h: In function ‘void sigc::visit_each(const T_action&, const sigc::bound_mem_functor0<T_return, T_obj>&) [with T_action = sigc::internal::limit_derived_target<sigc::trackable*, sigc::internal::slot_do_unbind>, T_return = void, T_obj = project::gui::Config]’:
/usr/include/sigc++-2.0/sigc++/adaptors/adaptor_trait.h:267:3:   instantiated from ‘void sigc::visit_each(const T_action&, const sigc::adaptor_functor<T_functor>&) [with T_action = sigc::internal::limit_derived_target<sigc::trackable*, sigc::internal::slot_do_unbind>, T_functor = sigc::bound_mem_functor0<void, project::gui::Config>]’
/usr/include/sigc++-2.0/sigc++/visit_each.h:170:3:   instantiated from ‘void sigc::visit_each_type(const T_action&, const T_functor&) [with T_type = sigc::trackable*, T_action = sigc::internal::slot_do_unbind, T_functor = sigc::adaptor_functor<sigc::bound_mem_functor0<void, project::gui::Config> >]’
/usr/include/sigc++-2.0/sigc++/functors/slot.h:60:7:   instantiated from ‘static void* sigc::internal::typed_slot_rep<T_functor>::destroy(void*) [with T_functor = sigc::bound_mem_functor0<void, project::gui::Config>]’
/usr/include/sigc++-2.0/sigc++/functors/slot.h:38:52:   instantiated from ‘sigc::internal::typed_slot_rep<T_functor>::typed_slot_rep(const T_functor&) [with T_functor = sigc::bound_mem_functor0<void, project::gui::Config>]’
/usr/include/sigc++-2.0/sigc++/functors/slot.h:451:65:   instantiated from ‘sigc::slot0<T_return>::slot0(const T_functor&) [with T_functor = sigc::bound_mem_functor0<void, project::gui::Config>, T_return = void]’
/usr/include/sigc++-2.0/sigc++/functors/slot.h:1130:26:   instantiated from ‘sigc::slot<T_return, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil>::slot(const T_functor&) [with T_functor = sigc::bound_mem_functor0<void, project::gui::Config>, T_return = void]’
src/gui/Config.cpp:72:96:   instantiated from here
/usr/include/sigc++-2.0/sigc++/functors/mem_fun.h:1806:3: error: ‘const class sigc::bound_mem_functor0<void, project::gui::Config>’ has no member named ‘obj_’
make: *** [src/gui/Config.o] Error 1

We're not sure if the problem really is related to the library sigc++ or if it's just a namespace problem. When we compiled the same file without the namespaces in a separate file, it worked.

Any idea is appreciated, Regards

Your class is privately inheriting from Gtk::Window

class gui::Config : Gtk::Window

vs

class gui::Config : public Gtk::Window

It looks like signals are trying to connect to these interfaces, but they are inaccessible.

You need to import all the three namespaces to the file where definitions are being provided.

using namespace project;
using namespace gui;
using namespace gtk;

void Config::connect_signals()
{
   // ...
}

But I see project, gui namespaces are redundant. Already Config is in namespace project. I don't understand your comment saying gui namespace is declared else where. This would suffice -

namespace project
{ 
    class Config : Gtk::Window  // The class being inherited is from a different namespace
    {
         //...