C#

T result = (T) CodeToRetrieveTofTheRightTypeDependingOnASettingInConfig();
return result;

Bastard Programmer from Hell
If you can't read my code, try converting it here[^]

Eddy Vluggen wrote:

a new overload for each type of constraint

Jörgen Andersson wrote:

without the caller knowing what type to expect

dynamic

class A { }
class B:A { }
class C:B { }

public static dynamic ConfigSetting(string s)
{
    switch (s)
    {
        case "A":
            return new A();
        case "C":
            return new C();
        case "double":
            return (double)123;
        case "int":
            return 123;
        default:
            return null as string;
    }
}

robwm1 wrote:

code that shows how to use the set accessor properly

robwm1 wrote:

Unfortunately, my instructors apparently don't write code so they are unable to answer my question.

robwm1 wrote:

code that shows how to use the set accessor properly

robwm1 wrote:

what does it look like if you try to assign a value from Main

static void Main(string[] args)
{
    Rectangle rect = new Rectangle(10, 20);
    
    // Try to set the width:
    // (This will fail)
    rect.Width = 0;
}

1. Remove the protected modifier from the <set>set accessors. The properties can then be set from any code.
   
   C#

   abstract class Polygon
   {
       public double Length { get; set; }
       public double Width { get; set; }
       abstract public double GetArea();
   }

2. Add a public method to the Polygon or Rectangle class to change the property values. This method can then be called from any code.
   
   C#

   abstract class Polygon
   {
       public double Length { get; protected set; }
       public double Width { get; protected set; }
       abstract public double GetArea();
       
       public void ChangeDimensions(double newLength, double newHeight)
       {
           Length = newLength;
           Height = newHeight;
       }
   }

3. If you want to preserve the immutability[^] of the class (Hint: This is almost always a good idea!), you'll need to create a new instance of the class with the new dimensions.