Re: [Boost-users] Why is boost::format::operator% not declared const?

void CalledThousandsOfTimesPerSecondFromManyThreads(float f) { static const boost::format Formatter("%0.3f");

GetStream() << Formatter % f << GetSomeOtherContent(); }

I'm pretty sure boost::format is not thread safe

If you think about what it's doing, every time you call operator% it's inserting a formatted item into it's internal state. Think about what happens if you feed multiple elements via operator% and then call .str() - you get a std::string back - it has to store everything you've fed in internally so that you can access the formatted string later via .str()