Re: Template multiple inheritance Organization: Roundhouse Consulting, Ltd.

That's what I thought but either I don't understand it (obviously...)
or the compiler doesn't support it. Here's a more complete example,
compiled with VS 2008:

class MyData
{};

struct BaseType
{
    BaseType() {}
    virtual ~BaseType() {}
    virtual void execute() = 0;
    virtual void connectTo(BaseType * dest, int outputPort, int
inputPort) = 0;
};

template <typename T>
struct Provider : virtual public BaseType
{
    virtual ~Provider() {}
    virtual T getValue() const = 0;
};

template <typename T, int port>
struct PortProvider : public Provider<T>
{
    virtual ~PortProvider() {}
    virtual T getValue() const
    {
        return getPortValue();
    }
    virtual T getPortValue() const = 0;
};

class BS :
    public PortProvider<MyData, 1>,
    public PortProvider<MyData, 2>
{
public:
    BS() : PortProvider<MyData, 1>(), PortProvider<MyData, 2>()
    {}

    virtual ~BS()
    {}

    virtual MyData PortProvider<MyData, 1>::getPortValue() const
    {}

    virtual MyData PortProvider<MyData, 2>::getPortValue() const
    {}

    virtual void execute()
    {}

    virtual void connectTo(BaseType * dest, int outputPort, int
inputPort)
    {}
};

int _tmain(int argc, _TCHAR* argv[])
{
    BS * bs1(new BS);
    return 0;
}

Error messages include:

error C3241: 'MyData BS::getPortValue(void)' : this method was not
introduced by 'PortProvider<T,port>'
error C2259: 'BS' : cannot instantiate abstract class due to following
members:
1> 'MyData PortProvider<T,port>::getPortValue(void) const' : is
abstract

Thanks.

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