This print for content only-size & color not accurate 7" X 9-1/4" / casebound / malloy

class PointRef  // <= Renamed and retyped.

{

public int x;

public int y;

public override string ToString()

{ return string.Format("({0}, {1})", x, y);}

}

As you are well aware, if the caller declares a variable of type Point, the memory is allocated on

the garbage-collected heap. The burning question then becomes, “What if an unsafe context wishes

to interact with this object (or any object on the heap)?” Given that garbage collection can occur at

any moment, imagine the problems encountered when accessing the members of Point at the very

point in time at which a sweep of the heap is under way. Theoretically, it is possible that the unsafe

context is attempting to interact with a member that is no longer accessible or has been reposi-

tioned on the heap after surviving a generational sweep (which is an obvious problem).

To lock a reference type variable in memory from an unsafe context, C# provides the fixed key-

word. The fixed statement sets a pointer to a managed type and “pins” that variable during the

execution of statement. Without fixed, pointers to managed variables would be of little use, since

garbage collection could relocate the variables unpredictably. (In fact, the C# compiler will not

allow you to set a pointer to a managed variable except in a fixed statement.)

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