Hi everyone - I'm new to boost-devel, and am a bit intimidated ;) I recently finished a project and I don't know if the boost community would have any interest in it, whether it's really "boost material" or not: https://github.com/KarenRei/safe-map The page goes into more detail, but the short of it is: after searching and a long conversation on StackExchange, I discovered that while there are threadsafe ordered-map containers out there, the threadsafety was a bit weak. For example, if you have Thread A iterating across the map and Thread B thread just happens to delete an element as A is passing by, A's iterator becomes invalidated and the program crashes - even in a supposedly "threadsafe" map. For the type of multithreaded cache that I needed, I needed a structure that had the thread safety level of a filesystem - you know, where multiple processes can have file descriptors open at a time and one process might even potentially delete a file that another is accessing, without leading to a system crash. And that's basically what I implemented: safe::map, which not only ensures that basic operations on the container itself are threadsafe, but that everything you do with the iterators - even deleting elements out of the map that other iterators are pointing to - is also threadsafe. It does this by implementing reference counting on the elements in the map and flagging elements for deletion rather than deleting them immediately. A more detailed description of usage, performance, implementation, use cases, etc is on the project page. The project comes with a test suite which launches a number of threads that endlessly randomly tweak and iterate around the map with every function available to them. Does this sound like something that might be useful in boost (after whatever changes would be required)? If there's no interest, no harm done :) - kv, Karen