Igor R. wrote:
The problem with this code is that you are returning a reference to data that might be immediately invalidated. A push_back via another thread can cause the referenced memory to no longer be valid.
Does push_back() really invalidate iterators to *previous* vector elements?!
Yes, and I quote the spec for insert which push_back() is based on: "Remarks: Causes reallocation if the new size is greater than the old capacity. If no reallocation happens, all the iterators and references before the insertion point remain valid." So unless you set capacity of the vector so that it never grows then push_back() can invalidate a held reference. Also it probably should be noted that even if you setup capacity so that the vector never grows and only allowed push_back() you still need mutex guards around any access to the shared object. KevinH -- Kevin Heifner heifner @ ociweb.com http://heifner.blogspot.com Object Computing, Inc. (OCI) www.ociweb.com