Understanding Rust Error E0255

Introduction to Rust Error E0255

Rust Error E0255 occurs when you attempt to import a value with the same name as another value already defined in the module. This can lead to ambiguity, as it's unclear which value should take precedence when referred to in the code.

Erroneous code example:

use bar::foo; // error: an item named `foo` is already in scope

fn foo() {}

mod bar {
     pub fn foo() {}
}

fn main() {}

Solutions to Rust Error E0255

You can resolve Rust Error E0255 using one of the following methods:

1. Using aliases

The simplest solution is to create an alias for the imported value, which will be unique within the module. By assigning a different name, it will no longer conflict with other values.

Example using aliases:

use bar::foo as bar_foo; // ok!

fn foo() {}

mod bar {
     pub fn foo() {}
}

fn main() {}

2. Referencing items with their parent

Another way to resolve this error is to explicitly refer to the value using its parent module within the code. This approach can be helpful for maintaining a clear understanding of where values originate.

Example referencing items with their parent:

fn foo() {}

mod bar {
     pub fn foo() {}
}

fn main() {
    bar::foo(); // we get the item by referring to its parent
}

Conclusion

Rust Error E0255 is caused by importing a value with the same name as another value already defined in the module. To resolve this error, use either an alias or explicitly reference the item with its parent module. By doing so, you will ensure that the code remains conflict-free and unambiguous.