Much of what you say is true, but I'm not sure that this is: > (on the other hand, C++'s "zero cost abstraction" philosophy requires the same level of trust).

Much of what you say is true, but I'm not sure that this is: > (on the other hand, C++'s "zero cost abstraction" philosophy requires the same level of trust). The C++ Standard _requires_ that a Standard Library implementation implements certain performance guarantees - I don't think the C Standard has such requirements. This means that certain implementations are effectively required - for instance that std::map is implemented (for better or worse) as a red-black tree.