How to Contribute

See the clap-wide CONTRIBUTING.md. This will contain clap_derive specific notes.

Derive Gotchas

Always prefix generated variables with __clap_ to minimize clashes with the user's variables, see #2934.
Prefer the path clap over ::clap to allow users to re-export clap, see #2258.
Prefer substituting variable names to avoid problems with macro_rules, see #2823.
Prefer ::std::result::Result and ::std::option::Option, see #3092.
Put whitespace between #quoted #variables.