>>>>>>>(1) The short way is to cast the return result to UInteger, and change the return type of GetCrc32() to UInteger
>>>>>>
>>>>>>IIRC you can't do that cast in VB (although you can in C# using 'unchecked')
>>>>>
>>>>>
>>>>>Viv,
>>>>>
>>>>>I don't know, but I'd be very surprised if it weren't possible
>>>>
>>>>Just tried this which won't compile:

Dim test As UInteger = DirectCast(Int32.MaxValue, UInteger)

>>>>If it was a valid cast what resulting UInteger would you expect from a negative value signed int ?
>>>>In C#:

unchecked { UInt32 test = ((UInt32)Int32.MinValue); }

>yields 2147483648....
>>>
>>>
>>>Firstly, I'm surprised that it yields an even number
>>>
>>>Secondly, if that's the case, I guess you'll need t check whether is was negative, and if so, set the left most bit after the 'cast'
>>
>>But if the signed int is negative then there is no accurate equivalent for an unsigned int ?
>>I'm assuming the C# cast simple treats the 32 bits as being an unsigned value ?
>>FWIW:

unchecked { Int32 test = ((Int32)UInt32.MaxValue);

>gives -1
>
>
>Yes, of course, all bits set is signed -1 and unsigned the max value
>
>When the leftmost bit is set in a signed int type, then it is considered as negative
>
>>But if the signed int is negative then there is no accurate equivalent for an unsigned int ?
>
>Viv, this isn't about maths. The crc32 is just a structure that is 32 bits wide

That's why I said : "I'm assuming the C# cast simple treats the 32 bits as being an unsigned value"

>If you think about it as a signed 32 bit structure and the leftmost bit is set then the number is negative
>
>If you look at it as an unsigned 32 bit structure, the same pattern is a number >= 0

I understand that - my point was that, in normal application usage, converting a negative signed int to an unsigned int would not make sense.