[boost] cannot get lambda::bind to work with abstract class (even with boost::ref)

From: Brock Peabody (brock.peabody_at_[hidden])
Date: 2003-10-24 13:38:00

I'm sure I'm missing something simple again, but if I try to compile:

   #include <boost/lambda/bind.hpp>

   struct a_struct {

      virtual void f() = 0;
   };

   void f(a_struct&);

   int
   main() {

      a_struct* a;

      boost::lambda::bind(&f, boost::ref(*a));  

      return 0;
   }

With MSVC 7.1 I get an error message like: "c:\Program Files\Microsoft
Visual Studio .NET 2003\Vc7\include\boost\tuple\detail\tuple_basic.hpp(354)
: error C2259: 'a_struct' : cannot instantiate abstract class
        due to following members:
        'void a_struct::f(void)' : pure virtual function was not defined..."

If I change it to use plain boost::bind instead of boost::lambda::bind it
works.  Lambda::var doesn't do the trick either.  Interestingly, if I change
the definition of a_struct to:

   struct a_struct : boost::noncopyable {
   private:

      a_struct();
   };

It works with lambda::bind.  As far as I can tell you shouldn't be able to
do anything with this version that you couldn't with the abstract base class
version.

Any ideas?

Thanks!

Brock