Re: [Boost-users] [lambda] Binding to simple object through smartpointer fails

12 Oct 2006


      Shortly after I posted this I got this working by first binding to 
boost::shared_ptr<T>::get method and then using the result of this as the 
this pointer in the main lambda expression.

"aDi Rob"  wrote in message 
news:egjsa1$9i$1@sea.gmane.org...
...
I am new to using lambda expressions and have come across a problem I can't 
seem to resolve - would appreciate any insight on this.
The following code fails to compile with VC++ 2003:
#include "stdafx.h"
class IX {
public:
 virtual double value() const = 0 ;
} ;
class X : public IX {
public:
 explicit X(double value) : value_( value ) {}
virtual double value() const { return value_ ; }
private:
 X() { }
 double value_ ;
} ;
int _tmain(int argc, _TCHAR* argv[])
{
 using namespace boost ;
 using namespace boost::lambda ;
 using namespace std ;
typedef boost::shared_ptr<IX> XPtr ;
XPtr x3( new X( 99 ) ) ;
 XPtr x4( new X( 199 ) ) ;
 std::vector<XPtr> xptrs ;
xptrs.push_back( x3 ) ;
 xptrs.push_back( x4 ) ;
 for_each(
   xptrs.begin(),
   xptrs.end(),
   std::cout << bind( &IX::value, _1 )
   ) ;
return 0;
}
I get the following compile-time error reported and i've looked at it and 
can't seem to locate the problem - if anyone could help me with this I 
would appreciate it, thanks. Adrian.
COMPILATION ERROR--->>>
u:\boost\1.32.0\include\boost\lambda\detail\actions.hpp(87) : error C2665: 
'boost::lambda::function_adaptor<Func>::apply' : none of the 2 overloads 
can convert parameter 2 from type 'std::allocator<_Ty>::value_type'
       with
       [
Func=boost::lambda::return_type_N,boost::lambda::lambda_functor_base>,boost::tuples::tuple::type,const boost::lambda::detail::bind_traits<const 
boost::lambda::placeholder1_type>::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type>>::sig>::rets_t>::plain_Func
       ]
       and
       [
           _Ty=XPtr
       ]
u:\boost\1.32.0\include\boost\lambda\detail\function_adaptors.hpp(179): 
could be 'Result boost::lambda::function_adaptor<Func>::apply<RET>(Result 
(__thiscall IX::* )(void) const,const Object *)'
       with
       [
           Result=double,
Func=boost::lambda::return_type_N,boost::lambda::lambda_functor_base>,boost::tuples::tuple::type,const boost::lambda::detail::bind_traits<const 
boost::lambda::placeholder1_type>::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type>>::sig>::rets_t>::plain_Func 
,
RET=boost::lambda::lambda_functor_base>,boost::tuples::tuple::type,const boost::lambda::detail::bind_traits<const 
boost::lambda::placeholder1_type>::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traits
...
::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type>>::sig>::type,
           Object=IX
       ]
u:\boost\1.32.0\include\boost\lambda\detail\function_adaptors.hpp(183): or 
'Result boost::lambda::function_adaptor<Func>::apply<RET>(Result 
(__thiscall IX::* )(void) const,const Object &)'
       with
       [
           Result=double,
Func=boost::lambda::return_type_N,boost::lambda::lambda_functor_base>,boost::tuples::tuple::type,const boost::lambda::detail::bind_traits<const 
boost::lambda::placeholder1_type>::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type>>::sig>::rets_t>::plain_Func 
,
RET=boost::lambda::lambda_functor_base>,boost::tuples::tuple::type,const boost::lambda::detail::bind_traits<const 
boost::lambda::placeholder1_type>::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traits
...
::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type>>::sig>::type,
           Object=IX
       ]
       while trying to match the argument list '(const rt0 , 
std::allocator<_Ty>::value_type)'
       with
       [
           _Ty=XPtr
       ]
u:\boost\1.32.0\include\boost\lambda\detail\lambda_functor_base.hpp(408) : 
see reference to function template instantiation 'RET 
boost::lambda::function_action<I>::apply(A1 & 
,A2 &)' being compiled
       with
       [
RET=boost::lambda::lambda_functor_base>,boost::tuples::tuple::type,const boost::lambda::detail::bind_traits<const 
boost::lambda::placeholder1_type>::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type>>::sig>::type,
           I=2,
           U=const rt0,
           T=IX,
           A1=const rt0,
           A2=std::allocator<XPtr>::value_type
       ]
u:\boost\1.32.0\include\boost\lambda\detail\select_functions.hpp(30) : see 
reference to function template instantiation 'RET 
boost::lambda::lambda_functor_base::call::sig<SigArgs>::type,A,B,C,Env>(A 
&,B &,C &,Env &) const' being compiled
       with
       [
RET=boost::lambda::lambda_functor_base>,boost::tuples::tuple::type,const boost::lambda::detail::bind_traits<const 
boost::lambda::placeholder1_type>::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type>>::sig>::type,
           Act=boost::lambda::action<2,boost::lambda::function_action<2>>,
           Args=boost::tuples::tuple::type,const boost::lambda::detail::bind_traits<const 
boost::lambda::placeholder1_type>::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type:
:type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type>,
           SigArgs=boost::tuples::tuple,
           A=std::allocator<XPtr>::value_type,
           B=const boost::tuples::null_type,
           C=const boost::tuples::null_type,
           Env=const boost::tuples::null_type
       ]
u:\boost\1.32.0\include\boost\lambda\detail\operator_lambda_func_base.hpp(212) 
: see reference to function template instantiation 
'boost::lambda::lambda_functor_base::sig<SigArgs>::type 
boost::lambda::detail::select,A,B,C,Env>(const 
boost::lambda::lambda_functor<T> &,A &,B &,C &,Env &)' being compiled
       with
       [
           Act=boost::lambda::action<2,boost::lambda::function_action<2>>,
           Args=boost::tuples::tuple::type,const boost::lambda::detail::bind_traits<const 
boost::lambda::placeholder1_type>::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type>,
           SigArgs=boost::
tuples::tuple,
           A=std::allocator<XPtr>::value_type,
           B=const boost::tuples::null_type,
           C=const boost::tuples::null_type,
           Env=const boost::tuples::null_type,
T=boost::lambda::lambda_functor_base>,boost::tuples::tuple::type,const boost::lambda::detail::bind_traits<const 
boost::lambda::placeholder1_type>::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type>>
       ]
u:\boost\1.32.0\include\boost\lambda\detail\lambda_functors.hpp(148) : see 
reference to function template instantiation 'RET 
boost::lambda::lambda_functor_base::call::sig<SigArgs>::type,A,const 
boost::tuples::null_type,const boost::tuples::null_type,const 
boost::tuples::null_type>(A &,B &,C &,Env &) const' being compiled
       with
       [
RET=boost::lambda::lambda_functor_baseboost::lambda::leftshift_action,boost::tuples::tuplestd::ostream::type>::RET,boost::lambda::lambda_functor>,boost::tuples::tuple::type,const boost::lambda::detail::bind_traits<const 
boost::lambda::placeholder1_type>::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type>>>,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type>>::sig>::type,
           Act=boost::lambda:
:bitwise_actionboost::lambda::leftshift_action,
Args=boost::tuples::tuplestd::ostream::type>::RET,boost::lambda::lambda_functor>,boost::tuples::tuple::type,const boost::lambda::detail::bind_traits<const 
boost::lambda::placeholder1_type>::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type>>>,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type>,
           SigArgs=boost::tuples::tuple,
           A=std::allocator<XPtr>::value_type,
           B=const boost::tuples::null_type,
           C=const boost::tuples::null_type,
           Env=const boost::tuples::null_type
       ]
       c:\Program Files\msvs2003\Vc7\include\algorithm(21) : see reference 
to function template instantiation 
'boost::lambda::lambda_functor_base::sig<SigArgs>::type 
boost::lambda::lambda_functor<T>::operator 
()::value_type>(A &) const' being compile
d
       with
       [
Act=boost::lambda::bitwise_actionboost::lambda::leftshift_action,
Args=boost::tuples::tuplestd::ostream::type>::RET,boost::lambda::lambda_functor>,boost::tuples::tuple::type,const boost::lambda::detail::bind_traits<const 
boost::lambda::placeholder1_type>::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type>>>,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type>,
           SigArgs=boost::tuples::tuple,
T=boost::lambda::lambda_functor_baseboost::lambda::leftshift_action,boost::tuples::tuplestd::ostream::type>::RET,boost::lambda::lambda_functor>,boost::tuples::tuple::type,const 
boost::lambda::detail::bind_traits<const 
boost::lambda::placeholder1_type>::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type>>>,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type>>,
           _Ty=XPtr,
           A=std::allocator<XPtr>::value_type
       ]
       c:\development\lambdaSpike\lambdaSpike.cpp(56) : see reference to 
function template instantiation '_Fn1 
std::for_each::iterator,boost::lambda::lambda_functor<T>>(_InIt,_InIt,_Fn1)' 
being compiled
       with
       [
_Fn1=boost::lambda::lambda_functorboost::lambda::leftshift_action,boost::tuples::tuplestd::ostream::type>::RET,boost::lambda::lambda_functor>,boost::tuples::tuple::type,const boost::lambda::detail::bind_traits<const 
boost::lambda::placeholder1_type>::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_tr
aitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type>>>,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type>>>,
           _Ty=XPtr,
T=boost::lambda::lambda_functor_baseboost::lambda::leftshift_action,boost::tuples::tuplestd::ostream::type>::RET,boost::lambda::lambda_functor>,boost::tuples::tuple::type,const boost::lambda::detail::bind_traits<const 
boost::lambda::placeholder1_type>::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type,boost::lambda::detail::bind_traitsboost::tuples::null_type::type>>>,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tuples::null_type>>,
           _InIt=std::vector<XPtr>::iterator
       ]
Build Time 0:01
Build log was saved at 
"file://c:\development\lambdaSpike\Debug\BuildLog.htm"
lambdaSpike - 1 error(s), 0 warning(s)