I like the ideas you put forth here. Though, I wonder if it could be taken a few steps further ... A boost formatting library 81 typedef boost::format::context_adapter< 82 struct timeval, 83 boost::format::context_spec< 84 boost::format::context_element<'d', ... > 85 > > timeval_context_t; 86 87 boost::format::basic_formatter<timeval_context_t> fmt; 88 89 struct timeval tv; 90 gettimeofday(&tv, NULL); 91 92 // Standard usage 93 std::cout << fmt("%d:%d",tv.tv_sec, tv.tv_usec) << std::endl; 94 95 // Output the first, then the second context elements 96 std::cout << fmt("%{1}:%{2}",tv) << std::endl; I like where the idea is taking me and I'm working on the implementation details now On Tue, Sep 13, 2011 at 6:11 PM, Vicente J. Botet Escriba < vicente.botet@wanadoo.fr> wrote: