Hello, I'm not sure if it is still topic but here is the minimum code to reproduce the problem. [----CODE----] #include <string> #include <algorithm> int main() { std::string par ( "produces help message slkfjsd lskdjf slkjf sdlkfj sdlkfj sdlkfj sdf lksdj" ); unsigned int line_length = 79, indent = 33; std::string::const_iterator line_begin = par.begin(); std::string::const_iterator line_end = line_begin + (line_length - indent); // find last ' ' in the second half of the current paragraph line std::string::const_iterator last_space = std::find(std::reverse_iterator<std::string::const_iterator>(line_end - 1), std::reverse_iterator<std::string::const_iterator>(line_begin - 1), ' ') .base(); return 0; } Regards, Elviin