Covariance and contravariance real world example

Question

I\'m having a little trouble understanding how I would use covariance and contravariance in the real world.

So far, the only examples I\'ve seen have been the same o

Answer 1

From MSDN

The following code example shows covariance and contravariance support for method groups

static object GetObject() { return null; }
static void SetObject(object obj) { }

static string GetString() { return ""; }
static void SetString(string str) { }

static void Test()
{
    // Covariance. A delegate specifies a return type as object, 
    // but you can assign a method that returns a string.
    Func