In EASTL http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2271.htmlthere is something like SSO (Small String Optimization) applied to std::vector (and other STL containers) [begin quote] "Fixed containers are fixed-size containers with their memory stored right within the container itself. Fixed containers allocate no dynamic memory and their memory tends to be cache-friendly due to its contiguity and proximity to the container's housekeeping data. The user declares the max container size as a template parameter, and can also specify that if the container overflows that an auxiliary dynamic allocator is used. template <typename T, size_t nodeCount, bool enableOverflow = true, typename Allocator overflowAllocator = EASTLAllocator> class fixed_vector { ... }; [end quote] I have tried a similar approach using some sort of fixed_buffer_with_overflow allocator, with no success. I'm not sure SSO is even possible just using an allocator with the standard containers, because I always end up with stateful allocators. So my question is if there is something similar already in boost. TIA