Print usage help if parse failed

[BMBurstein]

If the parse fails, I get a message like this:

-i is required
Run with --help for more information.

How can I have it print the usage string, too, instead of requiring another run with --help? i.e. I want a message similar to this:

-i is required

Usage: ./output.s [OPTIONS]

Options:
  -h,--help                   Print this help message and exit
  -i INT REQUIRED             My int

[phlptp]

the definition of CLI11_PARSE is

#ifndef CLI11_PARSE
#define CLI11_PARSE(app, argc, argv)                                                                                   \
    try {                                                                                                              \
        (app).parse((argc), (argv));                                                                                   \
    } catch(const CLI::ParseError &e) {                                                                                \
        return (app).exit(e);                                                                                          \
    }
#endif

If you wanted the help to print on an error what you would probably want on your parsing instead of using the MACRO is

  try {
        app.parse(argc, argv);                
    } catch(const CLI::ParseError &e) {   
        auto retval=app.exit(e);  
        if (retval!=   static_cast<int>(ExitCodes::Success)
        {
             out<< app.help();
         }    
    }

[phlptp]

Another Probably better option is

app.failure_message(CLI::FailureMessage::help);

or you could define your custom callback function to go into the failure_message callback to do whatever you wanted to do.