Use Struct for flags/options

[mrrooijen]

It'd be nice if we could figure out a way to use a Struct rather than a Hash for retrieving options from flags. Currently we have to do the following:

options.string["env"]    # => "development"
options.int["port"]      # => 8080
options.float["timeout"] # => 29.5
options.bool["verbose"]  # => false

It'd be nice if we could simply do the following instead:

options.env     # => "development"
options.port    # => 8080
options.timeout # => 29.5
options.verbose # => false

This way there will be no need to perform Nil-checks since there won't be any potentially missing keys unlike with Hashes.

Not sure how to accomplish this yet. Potentially with the use of macros to dynamically build structs at compile-time. Or, perhaps allow the user to manually define a struct and pass it in to the flags. Haven't looked into it yet.