Error code E0704

An incorrect visibility restriction was specified.

Erroneous code example:

#![allow(unused)] fn main() { mod foo { pub(foo) struct Bar { x: i32 } } }

To make struct Bar only visible in module foo the in keyword should be used:

mod foo { pub(in crate::foo) struct Bar { x: i32 } } fn main() {}

For more information see the Rust Reference on Visibility.