Two days ago I was asked to have a look at a nonworking piece of code, based on boost::program_options, which went like this: options_description desc(“Usage”); desc.add_options() (“host,h”, value<string>(), “The host.”) (“file,f”, value<string>(), “This is the file.”); (“mode,m”, value<string>(), “The mode.”); If you don’t recognise the syntax, know that add_options() method of options_description returns a builder object (options_description_easy_init), with an operator () taking three parameters, which …