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From: hyrosen@mail.com (Hyman Rosen)
Newsgroups: comp.lang.ada
Subject: Re: Is the Writing on the Wall for Ada?
Date: 12 Sep 2003 13:11:40 -0700
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"Robert I. Eachus" <rieachus@attbi.com> wrote in message news:<3F615341.4000100@attbi.com>...
> There is no way to directly inherit from two 
> classes, unless one is a subclass of the other.

I am well an truly puzzled at this remark.
Let me give a C++ example, and you can tell me why you don't believe it.

struct Colorable
{
    virtual void setColor(int color) = 0;
    virtual int getColor() = 0;
    virtual ~Colorable() { }
};
struct ColorableAdapter : virtual Colorable
{
    void setColor(int color) { m_color = color; }
    int getColor() { return m_color; }
    ColorableAdapter(int color = 0) : m_color(color) { }
private:
    int m_color;
};

struct Resizable
{
    virtual void setSize(double size) = 0;
    virtual double getSize() = 0;
    virtual ~Resizable() { }
};
struct ResizableAdapter : virtual Resizable
{
    void setSize(double size) { m_size = size; }
    double getSize() { return m_size; }
    ResizableAdapter(double size = 1) : m_size(size) { }
private:
    double m_size;
};

struct MyObject : ColorableAdapter, ResizableAdapter
{
    MyObject(int color = 0, double size = 1)
        : ColorableAdapter(color), ResizableAdapter(size)
    { }
    void doSomething();
};