Dear Volodya,
I've committed a change which cause the error message to look like:
error: in option 'compression': invalid option value 'foo'
what do you think? Then only problem is the case where an option has a short version: if you run
./first -c foo
then the error message will be exactly the same, which requires the user to mantally link "-c" to "compression". Do you think it's a problem?
There are always going to be problems where the option name was not fully specified on the command line (e.g. --compre 'foo') and I had first wondered if it would be possible to echo what was actually typed in. This proved to be too much effort.. Otherwise you would actually have to remember the parsed item as well as which option it mapped to... Do you think option '--compression' is clearer? Thanks for your time Leo