Creating unary function by binding-2nd to class member

From:

Marcin Gil <marcin.gil@NOSPAMgmail.com>

Newsgroups:

comp.lang.c++

Date:

Tue, 20 Feb 2007 09:50:59 +0100

Message-ID:

<erecpk$ana$1@news.onet.pl>

Hi!

I have the code like this
(obvious things like ctor/dtor removed)

typedef struct _NODE
{
   int val;
   int index;
} Node;

struct A:
{
   std::vector<Node*> Nodes;

   bool EqIndex(const Node* ptr, int idx) const
     { return ptr->index == idx; };

   int foo();
}

I would like to write like this:

int A::foo()
{
   ...
   std::find_if(Nodes.begin(), Nodes.end(), bind2nd(&A:EqIndex, 5));
   ...
}

but got these errors:

1>c:\program files\microsoft visual studio 8\vc\include\functional(303)
: error C2825: '_Fn2': must be a class or namespace when followed by '::'
1> main.cpp(361) : see reference to class template instantiation
'std::binder2nd<_Fn2>' being compiled
1> with
1> [
1> _Fn2=bool (__thiscall A::* )(const Node*,unsigned long)
1> ]
1>c:\program files\microsoft visual studio 8\vc\include\functional(303)
: error C2039: 'first_argument_type' : is not a member of '`global
namespace''
1>c:\program files\microsoft visual studio 8\vc\include\functional(303)
: error C2146: syntax error : missing ',' before identifier
'first_argument_type'
1>c:\program files\microsoft visual studio 8\vc\include\functional(303)
: error C2065: 'first_argument_type' : undeclared identifier
1>c:\program files\microsoft visual studio 8\vc\include\functional(304)
: error C2825: '_Fn2': must be a class or namespace when followed by '::'
1>c:\program files\microsoft visual studio 8\vc\include\functional(304)
: error C2039: 'result_type' : is not a member of '`global namespace''
1>c:\program files\microsoft visual studio 8\vc\include\functional(304)
: error C2146: syntax error : missing ',' before identifier 'result_type'
1>c:\program files\microsoft visual studio 8\vc\include\functional(304)
: error C2065: 'result_type' : undeclared identifier
1>c:\program files\microsoft visual studio 8\vc\include\functional(305)
: error C2955: 'std::unary_function' : use of class template requires
template argument list
1> c:\program files\microsoft visual studio
8\vc\include\functional(21) : see declaration of 'std::unary_function'
1>c:\program files\microsoft visual studio 8\vc\include\functional(307)
: error C2825: '_Fn2': must be a class or namespace when followed by '::'
1>c:\program files\microsoft visual studio 8\vc\include\functional(307)
: error C2143: syntax error : missing ',' before '`global
namespace'::first_argument_type'
1>c:\program files\microsoft visual studio 8\vc\include\functional(308)
: error C2825: '_Fn2': must be a class or namespace when followed by '::'
1>c:\program files\microsoft visual studio 8\vc\include\functional(308)
: error C2143: syntax error : missing ',' before '`global
namespace'::result_type'
1>c:\program files\microsoft visual studio 8\vc\include\functional(309)
: error C2955: 'std::unary_function' : use of class template requires
template argument list
1> c:\program files\microsoft visual studio
8\vc\include\functional(21) : see declaration of 'std::unary_function'
1>c:\program files\microsoft visual studio 8\vc\include\functional(310)
: error C2955: 'std::unary_function' : use of class template requires
template argument list
1> c:\program files\microsoft visual studio
8\vc\include\functional(21) : see declaration of 'std::unary_function'
1>c:\program files\microsoft visual studio 8\vc\include\functional(312)
: error C2825: '_Fn2': must be a class or namespace when followed by '::'
1>c:\program files\microsoft visual studio 8\vc\include\functional(312)
: error C2825: '_Fn2': must be a class or namespace when followed by '::'
1>c:\program files\microsoft visual studio 8\vc\include\functional(312)
: error C2039: 'second_argument_type' : is not a member of '`global
namespace''
1>c:\program files\microsoft visual studio 8\vc\include\functional(312)
: error C2143: syntax error : missing ',' before '&'
1>c:\program files\microsoft visual studio 8\vc\include\functional(330)
: error C2825: '_Fn2': must be a class or namespace when followed by '::'
1>c:\program files\microsoft visual studio 8\vc\include\functional(330)
: error C2039: 'second_argument_type' : is not a member of '`global
namespace''
1>c:\program files\microsoft visual studio 8\vc\include\functional(330)
: error C2146: syntax error : missing ';' before identifier 'value'
1>c:\program files\microsoft visual studio 8\vc\include\functional(330)
: error C4430: missing type specifier - int assumed. Note: C++ does not
support default-int

: error C2664: 'std::find_if' : cannot convert parameter 3 from
'std::binder2nd<_Fn2>' to 'std::binder2nd<_Fn2>'
1> with
1> [
1> _Fn2=bool (__thiscall A::* )(const Node *,unsigned long)
1> ]
1> Cannot copy construct class 'std::binder2nd<_Fn2>' due to
ambiguous copy constructors or no available copy constructor
1> with
1> [
1> _Fn2=bool (__thiscall A::* )(const Node *,unsigned long)
1> ]

What I do wrong?
Using MS Visual Studio 8.

If I write a functor derived from unary_function it works but I'd prefer
using single member function...

Thanks,
-Marcin