[Bug libstdc++/50320] New: Calling tr1 binder with constant expression fails

["martinhaefner at web dot de" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50320

             Bug #: 50320
           Summary: Calling tr1 binder with constant expression fails
    Classification: Unclassified
           Product: gcc
           Version: 4.4.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: martinhaefner@web.de


The following code fragment does yield a compiler error:


#include <tr1/functional>

void f(int i)
{
   // do something
}

template<typename BinderT>
void call(BinderT b)
{
//   int i = 42; b(i);    // <--- would be ok
   b(42);                 // <--- compiler error
}

int main()
{
   call(std::tr1::bind(f, std::tr1::placeholders::_1));
   return 0;
}


mmes@ubuntu:~$ g++-4.4 bind.cpp
bind.cpp: In function âvoid call(BinderT) [with BinderT = std::tr1::_Bind<void
(*(std::tr1::_Placeholder<1>))(int)>]â:
bind.cpp:17:   instantiated from here
bind.cpp:12: error: no match for call to â(std::tr1::_Bind<void
(*(std::tr1::_Placeholder<1>))(int)>) (int)â
/usr/include/c++/4.4/tr1_impl/functional:1189: note: candidates are: typename
std::tr1::result_of<_Functor(typename
std::tr1::result_of<std::tr1::_Mu<_Bound_args,
std::tr1::is_bind_expression::value, (std::tr1::is_placeholder::value >
0)>(_Bound_args, std::tr1::tuple<_UElements ...>)>::type ...)>::type
std::tr1::_Bind<_Functor(_Bound_args ...)>::operator()(_Args& ...) [with _Args
= int, _Functor = void (*)(int), _Bound_args = std::tr1::_Placeholder<1>]
/usr/include/c++/4.4/tr1_impl/functional:1200: note:                 typename
std::tr1::result_of<const _Functor(typename
std::tr1::result_of<std::tr1::_Mu<_Bound_args,
std::tr1::is_bind_expression::value, (std::tr1::is_placeholder::value >
0)>(_Bound_args, std::tr1::tuple<_UElements ...>)>::type ...)>::type
std::tr1::_Bind<_Functor(_Bound_args ...)>::operator()(_Args& ...) const [with
_Args = int, _Functor = void (*)(int), _Bound_args = std::tr1::_Placeholder<1>]
/usr/include/c++/4.4/tr1_impl/functional:1212: note:                 typename
std::tr1::result_of<volatile _Functor(typename
std::tr1::result_of<std::tr1::_Mu<_Bound_args,
std::tr1::is_bind_expression::value, (std::tr1::is_placeholder::value >
0)>(_Bound_args, std::tr1::tuple<_UElements ...>)>::type ...)>::type
std::tr1::_Bind<_Functor(_Bound_args ...)>::operator()(_Args& ...) volatile
[with _Args = int, _Functor = void (*)(int), _Bound_args =
std::tr1::_Placeholder<1>]
/usr/include/c++/4.4/tr1_impl/functional:1225: note:                 typename
std::tr1::result_of<const volatile _Functor(typename
std::tr1::result_of<std::tr1::_Mu<_Bound_args,
std::tr1::is_bind_expression::value, (std::tr1::is_placeholder::value >
0)>(_Bound_args, std::tr1::tuple<_UElements ...>)>::type ...)>::type
std::tr1::_Bind<_Functor(_Bound_args ...)>::operator()(_Args& ...) const
volatile [with _Args = int, _Functor = void (*)(int), _Bound_args =
std::tr1::_Placeholder<1>]


While calling the binder with a variable works perfectly. I am expecting that
binding a constant expression also works (as done by boost binders).

Regards,
Martin