Gusket

Gusket is a getter/setter derive macro.

Comparison with getset:

• gusket only exposes one derive macro. No need to derive(Getters, MutGetters, Setters) all the time. This avoids accidentally forgetting some derives, e.g. writing #[getset(get_copy)] with only #[derive(getset::Getters)] will generate nothing without triggering a compile error.
• gusket uses the struct visibility by default. This means that the usual boilerplate #[getset(get = "pub", get_mut = "pub", set = "pub")] is simplified to just #[gusket].
• gusket generates code from the span of the field (not the derive call), so error messages are more readable.