Hello Maxim, Wednesday, August 22, 2007, 9:54:59 PM, you wrote:
A couple of general comments after reading other reviews.
1. The fact that the library takes all arguments by reference looks unavoidable. If it allowed passing by value (i.e. making copies) - the copy constructors can throw, and this exception will be thrown after you made the change to your container/whatever you'd like to rollback, and before you setup the rollback action. So you can't guarantee that your rollback action will be executed.
So, in case you need a copy - it's much safer to create this copy before making the change to your container/whatever. It will also express your intention more clearly.
Generally speaking, you are right here. But first, there are many objects that don't throw on copying. And second, it's not always possible to make a copy beforehand. See one of my previous posts for an example (inserting into container yelds an iterator that is to be used in the scope-exit block). So I think the best way is to leave the decision up to user. -- Best regards, Andrey mailto:andysem@mail.ru