When accessing items defined in the parent module, it is tempting to write use super::*;. However, this does not allow accessing private items. For example, this fails:
fn print_hello() {
println!("hello");
}
mod inner {
use super::*;
pub fn do_something() {
print_hello(); // error: unresolved name `print_hello` [E0425]
}
}This is a mistake I've made several times (I suspect many others have too) and the solution is to be explicit about the item used, either with
or
On this topic, the Rust Reference says:
Use declarations support a number of convenient shortcuts:
- ...
- Binding all paths matching a given prefix, using the asterisk wildcard syntax
use a::b::*;
- ...
I find this a bit misleading because the asterisk wildcard syntax really only binds public paths matching a given prefix.
I think it would be nice to add a paragraph in the Rust Book to explain how to access private items properly and to state clearly that use super::* won't help.
When accessing items defined in the parent module, it is tempting to write
use super::*;. However, this does not allow accessing private items. For example, this fails:This is a mistake I've made several times (I suspect many others have too) and the solution is to be explicit about the item used, either with
or
On this topic, the Rust Reference says:
I find this a bit misleading because the asterisk wildcard syntax really only binds public paths matching a given prefix.
I think it would be nice to add a paragraph in the Rust Book to explain how to access private items properly and to state clearly that
use super::*won't help.