Re: pure virtual method

From:

"BobR" <removeBadBobR@worldnet.att.net>

Newsgroups:

comp.lang.c++

Date:

Mon, 27 Aug 2007 20:42:31 GMT

Message-ID:

<XGGAi.56800$ax1.48794@bgtnsc05-news.ops.worldnet.att.net>

<mfabricius@gmail.com> wrote in message...

Hi,
I am probably trying to do something really stupid.
There is a class shape:

class Shape{ public:
Shape();
virtual ~Shape();
...
virtual bool inside(prec_t x, prec_t y) = 0;
...
virtual Shape * copy() = 0;
...
};

You might want to 'define' those pure virtuals for testing.

bool Shape::inside( prec_t x, prec_t y){
    std::cerr<<"base virtual \"Shape::inside()\" called"<<std::endl;
    return false;
    }

Shape* Shape::copy(){
    std::cerr<<"base virtual \"Shape::copy()\" called"<<std::endl;
    return this;
    }

..... because of this:

class Surface{ public: ...
    Shape* myShape; // <--------! slice if set to a derived?
    }; // ADD the semicolon!!!

1) upperShell.shape = this->shape->copy();

There is no 'upperShell' in the incomplete code you showed.
There is no 'shape' in the incomplete code you showed.
( did you mean 'myShape'? )

You also failed to show the definitions for:
Circle::inside()
Circle::copy()

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--
Bob R
POVrookie