Is there a way to tell a flag is set by user but not by default value?

[dio]

kong.Value has Set property: Set to true when this value is set through some mechanism. Is there a way to tell that a flag is set by users?

var (
        cli struct {
               Foo string `help:"foo" default:"bar"`
        }
)

To tell the difference between the following:

$ cli --foo bar

$ cli 

[alecthomas]

As in being able to differentiate between being set by an envar and being set by a flag? No there isn't currently.

[shueybubbles]

How hard would it be to support pointer types like

var (
    cli struct {
        MyArg *string 
    }
)

such that arguments not passed on the command line end up with null values in the struct? I have a similar scenario where I need to distinguish between the user passing a value to a flag and the user not passing the flag at all.

[alecthomas]

That is essentially what this PR does if you'd like to give it a shot, there's some minor feedback to be addressed but it mostly LGTM.

[mitar]

See #214.