import std.variant, std.stdio,std.typecons,std.meta;

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template Shape() {

    long x;

    long y;

}

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alias AllShapes = AliasSeq!(Cyrcle,Square,Rect);

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struct AnyShape {

    Algebraic!AllShapes shape;

    long opDispatch(string field)() {

        static foreach( P; AllShapes ) {

            if(shape.peek!P) return mixin( q{shape.get!P.} ~ field );

        }

        assert(false);

    }

    void opAssign( S )( S shape ) {

        this.shape = shape;

    }

}

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struct Cyrcle {

    mixin Shape;

    long radius;

}

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struct Square {

    mixin Shape;

    long size;

}

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struct Rect {

    mixin Shape;

    long width;

    long height;

}

​

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void main()

{

    AnyShape[3] shapes;

    shapes[0] = Cyrcle(1,2,3);

    shapes[1] = Square(4,5,6);

    shapes[2] = Rect(7,8,9,0);

    shapes[0].x.writeln;

    shapes[1].y.writeln;

    //shapes[2].width.writeln;

    shapes.sizeof.writeln;

    Cyrcle.sizeof.writeln;

    Square.sizeof.writeln;

    Rect.sizeof.writeln;

}

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