extension method on type and nullable

Question

For sake of simplicity, let\'s assume I want to write an extension method for the type int? and int:

public static class IntExtentions
{
    public static in         


        

Answer 1

No you cannot. This can be verified experimentally by compiling the following code

public static class Example {
  public static int Test(this int? source) {
    return 42;
  }
  public void Main() {
    int v1 = 42;
    v1.Test();  // Does not compile
  }
}

You will need to write an extension method for each type (nullable and not nullable) if you want it used on both types.