Argument indicates that the last element is an argument.

ChainShortOption indicates that a new short option may be chained.

DoubleDashTerminatesOptions indicates that all elements after an argument "--" are treated as arguments.

FirstArgTerminatesOptions indicates that all elements after the first argument are treated as arguments.

GNUGetoptLong is a configuration that should replicate the behavior of GNU getopt_long.

LongOnly indicates that long options may be started by either one or two dashes, and short options are not allowed.

LongOption indicates that the last element is a long option, but not its argument.

NewLongOption indicates that the last element must be a new long option.

NewOption indicates that the last element must be new option, short or long.

NewOptionOrArgument indicates that the last element may be either a new option or a new argument.

NoArgument indicates that an option takes no argument.

OptionalArgument indicates that an option takes an optional argument.

OptionArgument indicates that the last element list must be an argument to an option.

POSIXGetopt is a configuration that should replicate the behavior of POSIX getopt.

RequiredArgument indicates that an option must take an argument.

Context indicates what may come after the supplied argument list.

Getopt specifies the syntax of command-line arguments.

Option is a command-line option.

ParsedOption represents a parsed option.

Config configurates the parsing behavior.

ContextType encodes what may be appended to the last element of the argument list.

HasArg indicates whether an option takes an argument, and whether it is required.