[Boost-users] [Function] Overloaded functor as a boost::function

Subject: [Boost-users] [Function] Overloaded functor as a boost::function
From: Alexander Lamaison (awl03_at_[hidden])
Date: 2010-02-13 20:11:21

I'm trying to pass a function with an overloaded operator() to a function
expecting a boost::function parameter.  This fails to compile as it appears
to pick the wrong overload.

Here is the functor interface with the two ways it can be called:

class Command
{
public:
        virtual void operator()(
                const com_ptr<IShellItemArray>& items,
                const com_ptr<IBindCtx>& bind_ctx);

        virtual void operator()(
                const com_ptr<IDataObject>& data_object,
                const com_ptr<IBindCtx>& bind_ctx);
};

When I try to pass an instance of this functor to a method expecting a
boost::function of this type:
boost::function<void(
                const com_ptr<IShellItemArray>& items,
                const com_ptr<IBindCtx>& bind_ctx)>
I get a compiler error C2440: '=' : cannot convert from 'IShellItemArray *'
to 'IDataObject *'.  This seems to indicate that the boost::function is
trying to pass its parameters to the second overload rather than the first.

Any ideas how I can make boost::function pick the correct overload? I'm
using Boost 1.40.0.

Many thanks.

Alex Lamaison

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