Hello. Is there a way to use value returning C++0x lambdas with libsigc++?
Functions not returning values work fine:
sigc::slot <void> slot1 = [] () { };
sigc::slot <void, int> slot2 = [] (int) { };
no compilation problems. However when a return value is added:
sigc::slot <bool> slot3 = [] () -> bool { return true; };
sigc::slot <bool, int> slot4 = [] (int) -> bool { return true; };
I end up getting two compilation errors:
/usr/include/sigc++-2.0/sigc++/functors/slot.h:103:36: error: void
value not ignored as it ought to be
/usr/include/sigc++-2.0/sigc++/adaptors/adaptor_trait.h:251:21: error:
return-statement with a value, in function returning 'void'
Is that possible to achieve in some other way, or are lambdas with a return
value not supported by libsigc++ yet?
best regards
Jakub Łukomski
full output:
In file included from test.cc:1:0:
/usr/include/sigc++-2.0/sigc++/functors/slot.h: In static member function
‘static T_return sigc::internal::slot_call0<T_functor,
T_return>::call_it(sigc::internal::slot_rep*) [with T_functor = main(int,
char**)::<lambda()>, T_return = bool]’:
/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 = main(int, char**)::<lambda()>,
T_return = bool, 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 = main(int,
char**)::<lambda()>, T_return = bool]’
/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 = main(int,
char**)::<lambda()>, T_return = bool]’
test.cc:8:57: instantiated from here
/usr/include/sigc++-2.0/sigc++/functors/slot.h:103:36: error: void value not
ignored as it ought to be
In file included from /usr/include/sigc++-2.0/sigc++/functors/slot.h:7:0,
from test.cc:1:
/usr/include/sigc++-2.0/sigc++/adaptors/adaptor_trait.h: In member function
‘sigc::adaptor_functor<T_functor>::result_type
sigc::adaptor_functor<T_functor>::operator()() const [with T_functor =
main(int, char**)::<lambda()>, 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 = main(int,
char**)::<lambda()>, T_return = bool]’
/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 = main(int, char**)::<lambda()>,
T_return = bool, 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 = main(int,
char**)::<lambda()>, T_return = bool]’
/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 = main(int,
char**)::<lambda()>, T_return = bool]’
test.cc:8:57: instantiated from here
/usr/include/sigc++-2.0/sigc++/adaptors/adaptor_trait.h:251:21: error:
return-statement with a value, in function returning 'void'
--
Jakub Łukomski <d...@tenku.eu>
_______________________________________________
libsigc-list mailing list
libsigc-list@gnome.org
http://mail.gnome.org/mailman/listinfo/libsigc-list
