https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67503
--- Comment #11 from Marc Glisse <glisse at gcc dot gnu.org> --- (In reply to radventure from comment #9) > I understand the "small string optimization" idea. I agree about allocation > counting. But I don't see space economy, now sizeof(string) is 28 bytes in > 32-bit environment instead of 4 bytes early. It is a speed/space compromise. libc++ (the standard library implementation in llvm) wastes less space, but has to test whether the string is in "small string mode" for every operation, even read-only ones, whereas in libstdc++ you can read a string the same way whether it is short or long. Which approach is best most likely depends on applications, I am not aware of benchmarks about it.
