Hi all, I took time to write a simple benchmark for boost::any. Please find the code attached. It requires C++11. I could only test with g++ because clang 3.0/Ubuntu segfaults on the code. I'd be more than happy to get feedback on whether the tests are relevant. I think the compiler can't impact the result by optimizing away the payloads because there's the virtual call barrier preventing it from doing so. The results are quite good for a library that is not optimized yet. Here are some typical results on my machine (though results may vary slightly on each run): Times are in seconds for 100 million iterations, using -O3 -std=c++0x and no other special flags. * Classic inheritance replacement: Inherited: 0.261134 Erased: 0.260092 Erased + ctor: 0.343596 Erased + ctor 3 concepts: 0.295584 * boost::function replacement: boost::bind: 0.260356 boost::function: 0.469181 std::function: 0.515477 te::any + boost::bind: 0.494241 te::any + lambda: 0.379945 Basically that means that TypeErasure has a cost that's zero or at worse neglectible when compared to normal inheritance. It probably means that those simple use cases can't be optimized since the theoretical performance is achieved. If you create the any object each time, then there's something like a 30% loss. That's against an empty virtual function which means that for non trivial payloads the cost is still low. Good job ! The only thing I can't explain is why creating an any with 3 concepts in an mpl::vector is faster than a single primitive concepts. Any ideas ? Nice as well is that callable<> matches or bests boost::function in the simple cases I have tested (likely to be common thanks to C++ lambdas). Actually, I guess that the results would be even better in "normal" circumstances because the way I wrote the test any has 2 virtual call to perform. I guess that in that case again, optimization is not required before acceptance and release. Regards, Julien