Jonathan Graehl wrote:
I used to do this:
bool help_flag; options.add_options() ("help,h","produce help message"); help_flag=vm.count("help")
Now this is better:
bool help_flag; options.add_options() ("help,h", bool_switch(&help_flag),"produce help message");
I tried it, and it works, but the usage string is a little odd:
-h [ --help ] arg (=0) : produce help message -v [ --version ] arg (=0) : print the version number
Apologies for self-reply: It turns out that the "optional" nature of the argument to a bool_switch creates an impossible situation when positional arguments are used. For instance: myprogram -h positional_argument will try to parse positional_argument as a bool if I use a bool_switch for the -h option This seems like fairly useless behavior; bool_switch should *never* expect any argument (or, I should say, I'd like a version that doesn't consume my positional parameters). Also, in parsers.cpp, throw too_many_positional_options_error( "too much positional options"); should be "too many positional options". -Jonathan