a sequenece of inner option array type
a sequenece of inner option base type
a nullable variant which may contain one of type in OptionValueSeq
a sequenece of inner option type, equals to the union of OptionBaseValue and OptionArrayValue
a no-nullable variant which may contain one of type in OptionValueSeq
the callback for parsing the string value to the target type
furhter callback after using ParseArgFn
the callback for recursingly parsing the multiple values to only one value with same type, using in VariadicOption
the negate option like --no-flag, which is controller option that doesn't contains inner value.
the option type. store the value that command line's options input. we can get the inner value after it is initialized.
the source of the final option value gotten
creae a negate option
create bool option
create bool option
create value/variadic option, whose inner type or inner value's element type T must satisfy isBaseOptionValueType and not bool
create varidic option, whose inner values's element type T must satisfy isBaseOptionValueType and not bool
a trait func for checking whether a type is base inner option value (OptionBaseValue)
a trait func for checking whether a type is option inner value (OptionValueSeq)
The Option Type for Cmdline
This modlue mainly has Option Type. We can set the inner value by manly way. And if the Option value is valid, then we can initialize it and get the inner value.