I know there is a boost::format and it's great. However, I needed something faster and with more "conventional" syntax. That's the coutf library. I've been using it for a few months and it's great. Just to be clear, I'm not suggesting a replacement of boost::format, which has several features that coutf does not. However in many cases you don't need those and that's why coutf is a fair bit faster. Also the syntax is more conventional and several people have mentioned they prefer that. I know Alexandrescu has also created something similar to coutf (I think he called it Printf), but I think mine is lighter, I think most people are not too concerned about not being able to printf 45 parameters, plus it has the Fmt/FmtGuard stuff :) . Anyways the docs and code are at http://noptrlib.sf.net/utils/coutf, just did another update today. Coutf could be a good second alternative to boost::format for some people. Here are some examples of use: coutf("Program started at %s:%s:%s\n", hours, minutes, seconds); cerrf("Error: file %s, line %5s invalid\n", filename, lineNum); std::string msg = strf("Hex of %s is %04Xs", 123, 123); int count = 10; std::ofstream ff("someFile.txt"); // prints array in hex format { FmtGuard fmt(ff, "%0#4x"); for (int i=0;i<count;i++) scoutf( ff, 1 + intArray[i], '\n' ); } // print in dec format scoutf( ff, count ); BOOST_LOG(trace) << strf("File %s at line %s\n", __FILE__, __LINE__); Cheers, Oliver