Hi, I just wondering about two things with the format library. 1) The following program crashes on windows - is this intentional? #include <boost/format.hpp> int main(int argc, char* argv[]) { boost::format f("%s %s"); f.exceptions(boost::io::no_error_bits); // not needed, but just in case char const* null_cstr = 0; char const* empty_cstr = ""; f % empty_cstr; // triggers debug assertion failure f % null_cstr; // triggers access violation return EXIT_SUCCESS; } The debug assertion failure only happens on a debug build, of course. I can understand the access violation on a null string, but that feature makes it unsuitable for a sprintf replacement. 2) Is there a way to determine the number of expected arguments in a format object? Looks like the basic_format::num_args_ is exactly what I'm looking for, but I can't find this exposed anywhere. Going through a loop and catching exceptions is one way of getting the number of expected arguments, but it feels wrong. -- Eld på åren og sol på eng gjer mannen fegen og fjåg. [Jøtul] <demo> 2008 Tore Halvorsen || +052 0553034554