Reinitializing a variable allocated on stack
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In the code below the `cm` variable is allocated on the stack and the `addConstraints` is the prototype of a method : 

    ConstraintManager cm(5);

    void addConstraints(ConstraintManager& cm);

When I call addConstraints I want to reinitialize the cm variable inside the body of the function. That is call its constructor such as doing like `cm(3)`so that it is reinitialized to contain 3 instead of 5. However I am not able to do that and the only thing I can do is:

    ConstraintManager temp(3);
    cm = temp;

Is there a way to achieve this in a more concise way ? Thanks.