What does a GUID do for an interface?

[richardchaven]

What is the difference between an interface with a GUID and an interface without one?

I have hit several cases where I have to have a GUID, but I don't know exactly where the line is.

TIA

Cheers

 

[EricDraven]

If you read this page, it will tell you were the line is and explain the different interfaces in much better wording than I can at this time of the morning.

http://community.borland.com/article/0,1410,27825,00.html

Arte Et Labore

 

[richardchaven]

It says:

GUIDs are used to identify an interface and they must be used when using Supports(), "as", QueryInterface(), or GetInterface() methods. Though GUIDs are not always required, it is best to always include them.

It does not say what one can and cannot do with interfaces beyond these specific calls. Or, conversely, what can one do with interfaces that do not have a GUID ?

Cheers