Inherit no_version for enum variants

[dtolnay]

In my non-Cargo build environment I end up with a lot of noise from no_version attributes. For subcommands, if the outer enum is no_version I think I shouldn't need to specify no_version as well for each of the command variants.

Currently derive(StructOpt) produces an error if any of the no_version attrs here are removed:

use structopt::StructOpt;

#[derive(StructOpt)]
#[structopt(no_version)]
enum Show {
    #[structopt(no_version)]
    Stats,
    #[structopt(no_version)]
    Capacity,
}

[CreepySkeleton]

I agree. @TeXitoi what do you think?

By the way, @dtolnay , I wonder what non-cargo environment you're working with?

[CreepySkeleton]

By the way, it looks like a bug - #[structopt(no_verison)] should not (and need not to) be usable on enum variants, only on top of the struct or enum

[TeXitoi]

That's because the enum can be transformed to a clap::App, and that each enum is a subcommand that also generate a clap::App.

[CreepySkeleton]

I'll see if we can catch this situation. I also think that no_version should be propagated down to subcommands - if we don't want version for the program itself why would we wan a version for subcommands?

[CreepySkeleton]

@TeXitoi so what do you think about it? It can be implemented almost for no effort.

[TeXitoi]

Then OK for it