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Exercise 4.6
Conversion via constructors

In the program shown on the slide above, a Point can be converted to a Tripple via a constructor Tripple(Point). The other way around, we convert a Tripple to a Point with use of a conversion operator in class Tripple

In this exercise we want to provide for a more symmetric solution. We keep the constructor Tripple(Point). Your task is to program the symmetric constructor Point(Tripple). Your starting point is the header file and the cpp file

You may enconter a couple of minor challenges when you rewrite the program. First, class Tripple must now be declared (it must be known by the compiler) in order to compile class Point. The reason is that class Point now uses the name Tripple (in the new constructor).

As another challenge, the new constructor Point(Tripple) in class Point needs access to the three encapsulated, private data members in class Tripple. Consider setting up appropriate friendship, or program accessor member functions.

With this in place, rerun the program from above. Do you get the expected results (without surprises)?

On closer inspection, it seems wrong to copy a Point into a Tripple constructor, and the other way around. Program a variant where the relevant Point and Tripple constructors pass 'the other object' by const reference. Explain the changes you observe.