Allow `-long_name`

[apavlenko]

Is it possible to allow long names with a single dash? e.g. -log=errors-only obviously, short opt-s grouping should be disabled in this case

[vietjtnguyen]

Would the idea be that you can configure the parser just prior to parsing to either parse for short option groups or ignore short option groups and treat multi-character options as long options?

[apavlenko]

yes, this is exactly what I mean: the approach of grouping short options is popular but an alternative practice of using long options with a single dash is also popular enough. so I would recommend a flag in c-tor disabling grouping and allowing -l, -log and --log to be the same option.

[ajonnet]

XCode puts some default arguments, which breaks the argument parser "-NSDocumentRevisionsDebugMode"

Either a option to filter them or some sort of compatibility mode would be helpfull

[vietjtnguyen]

Merging with #23.

[vietjtnguyen]

Actually reopening this after https://github.com/vietjtnguyen/argagg/issues/23#issuecomment-458465334