public abstract class SomeClass
{
    // checks equality of each member in two arrays.
    public static bool ArrayEquals<T>(T[] a, T[] b)
    {
        if (a.Length != b.Length) {
            return false;
        }

        for (int i = 0; i < a.Length; i++) {
            if ( a[i] != b[i] ) {
                return false;
            }

        }
        return true;
    }
}

bool someMethod<T>(T a, T b)
{
    if ( a.Equals(b) )
    {
        Console.Writeline("Hooray!");
        return true;
    }
    return false;
}

class A : IEquatable<A>
{
	int m_int;

	public A(int a) { m_int = a; }

	public override bool Equals(object obj)
	{
		A other = obj as A;

		if (other == null)
			return false;

		return Equals(other);
	}

	public bool Equals(A other)
	{
		return m_int == other.m_int;
	}
}

static bool someMethod<T>(T a, T b)
{
	if (a.Equals(b))
	{
		Console.WriteLine("Hooray!");
		return true;
	}

	Console.WriteLine("Whoops!");
	return false;
}

[STAThread]
static void Main(string[] args)
{
	A a = new A(3);
	A b = new A(4);
	A a2 = new A(3);

	someMethod(a, b);
	someMethod(a, a2);
	someMethod(a2, b);
	
	Console.WriteLine("Finished");
	Console.ReadLine();
}

Whoops!
Hooray!
Whoops!
Finished