.possible_values/empty values with following arguments

[sylvestre]

Hi

I could not find how to do it with clap 2. So, asking the question here!

I have a program - let's call it "ls" which can take an argument --color with different values.
with --color is used without argument, we will take a default value.

It can also take X files as argument.
For example:

$ ls --color 
$ ls --color=always file.txt
$ ls --color file.txt

However, with the last case, I am getting
error: The argument '--color=<color>' requires a value but none was supplied
I would like to get the same behavior as the second case.

With the following clap declaration:

        .arg(
            Arg::with_name("color").long("color")
            .takes_value(true)
            .possible_values(&["always", "auto", "never"])
            .default_value("always")
            .require_equals(true)
            .empty_values(true)
        )

[pksunkara]

It's not possible in v2, but only in v3 because it is added in #1587

[sylvestre]

Looking forward to v3 then :)
thanks!