Why am I getting uninitialized memory reads from PurifyTM?
We believe that the uninitialized memory read (UMR) messages in STL data structures are artifacts and can be ignored. There are a number of reasons the compiler might generate reads from uninitialized memory (e.g. structure padding, inheritance from empty base classes, which still have nonzero size). Purify tries to deal with this by distinguishing between uninitialized memory reads (UMR) and uninitialized memory copies (UMC). The latter are not displayed by default. The distinction between the two isn’t completely clear, but appears to be somewhat heuristic. The validity of the heuristic seems to depend on compiler optimizations, etc. As a result, some perfectly legitimate code generates UMR messages. It’s unfortunately often hard to tell whether a UMR message represents a genuine problem or just an artifact.
