>>>>The WHERE restricts the classes it applies to.
>>>>
>>>>See possible clauses : http://msdn.microsoft.com/en-us/library/d5x73970.aspx
>>>>They can be combined - it's an AND combination
>>>>
>>>>If you want to use eg between/max, .., you want the type to implement IComparable(T)
>>>>

>>>>public static bool Between<T>(this T s, T s1, T s2) where T : IComparable<T>
>>>>
>>>>public static T Max<T>(params T[] array) where T : IComparable<T>
>>>>
>>>>

>>>>
>>>>For an InList you'll need IEquatable(T)
>>>>

>>>>public static bool InList<T>(this T s, params T[] array) where T : IEquatable<T>
>>>>		{
>>>>			return array.Contains(s);
>>>>		}
>>>>

>>>
>>>Gregory,
>>>
>>>Thanks a lot.
>>>
>>>Now I don't understand this
>>>

>>>public static T GetNonNull<T>(this  T? value) where T : struct
>>>		{
>>>			return value == null ? default(T) : (T)value;
>>>		}
>>>

>>>It says that it could be any value type except for Nullable types. But paramter of the method is Nullable type. Can you explain it then?
>>>
>>>Thanks a lot again.
>>
>>
>>I think it says that T must be a value type. The T? says it accepts the nullable version of the value type
>
>I think there is some contradiction I still don't understand. From the link:
>
>where T: struct
> The type argument must be a value type. Any value type except Nullable can be specified. See Using Nullable Types (C# Programming Guide) for more information.

probably means we cannot write

where T?: struct

>and then we're using nullable value type for the parameter. Why does it work?


We still pass T - except it is nullable