Comparison of Generics in C#

Question

Why does this code prints False?

    class Program
{
    public static void OpTest<T>(T s, T t) where T : class
    {
        Console.WriteLine(s == t);
    }

    static void Main()
    {
        string s1 = "string";
        System.Text.StringBuilder sb = new System.Text.StringBuilder(s1);
        string s2 = sb.ToString();
        OpTest(s1, s2);
    }
}

Do I understand correctly that when compared, they are compared not as strings, but as objects, which is why not their values are compared, but the addresses to which they point?

Answer 1

From the docs for the == operator:

For predefined value types, the equality operator (==) returns true if the values of its operands are equal, false otherwise. For reference types other than string, == returns true if its two operands refer to the same object. For the string type, == compares the values of the strings.

Since T cannot be guaranteed to be a value type as it's generic, the compiler must assume it is a reference type.