Sichtbarkeit
Modules are a privacy boundary:
- Module items are private by default (hides implementation details).
- Parent and sibling items are always visible.
- In other words, if an item is visible in module
foo
, it's visible in all the descendants offoo
.
mod outer { fn private() { println!("outer::private"); } pub fn public() { println!("outer::public"); } mod inner { fn private() { println!("outer::inner::private"); } pub fn public() { println!("outer::inner::public"); super::private(); } } } fn main() { outer::public(); }
This slide should take about 5 minutes.
- Use the
pub
keyword to make modules public.
Additionally, there are advanced pub(...)
specifiers to restrict the scope of public visibility.
- See the Rust Reference.
- Configuring
pub(crate)
visibility is a common pattern. - Less commonly, you can give visibility to a specific path.
- In any case, visibility must be granted to an ancestor module (and all of its descendants).