Dealing with property function and operator overloads
    Andrej Mitrovic 
    andrej.mitrovich at gmail.com
       
    Mon Oct  3 08:52:20 PDT 2011
    
    
  
Sample code:
struct Point
{
    int x, y;
    void opOpAssign(string op)(int rhs)
    {
        mixin("x = x " ~ op ~ " rhs;");
        mixin("y = y " ~ op ~ " rhs;");
    }
}
struct Wrapper
{
    void notifyChanged() { }
    @property void point(Point newpoint) { _p = newpoint; notifyChanged(); }
    @property Point point() { return _p; }
    private Point _p;
}
void main()
{
    auto wrap = Wrapper();
    wrap.point = Point(1, 1);
    assert(wrap.point == Point(1, 1));
    wrap.point += 1;
    assert(wrap.point != Point(2, 2));  // oops
}
I want to get notified when the _p field is changed. A property
function works for assignments, but by using property functions I lose
any operator overloads Point might have.
I was thinking I could provide some sort of injecting mechanism into
the Point definition, so I could get rid of property functions and
instead do something like this:
struct Wrapper
{
    this(...)
    {
        point.changed = ¬ifyChanged;
    }
    public Point point;
}
Has anyone ran into this issue before, and if so how did you work around it?
    
    
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