Understanding Rust Error E0365

What is Rust Error E0365?

Rust Error E0365 often occurs when a private module is mistakenly attempted to be publicly re-exported. Specifically, the code pub uses a module that isn't defined as public. In this article, we will examine the error in greater depth and provide a solution to rectify it.

An Example of Erroneous Code

mod foo {
    pub const X: u32 = 1;
}

pub use foo as foo2;

fn main() {}

In the code block above, the E0365 error is produced due to the attempt to pub use a module called foo that has not been defined as public. Since foo is private by default, the re-exporting of foo as foo2 cannot be publicly accessed.

Solution to Rust Error E0365

To resolve the issue, the module in question needs to be explicitly marked as public using the pub keyword. Below is the corrected version of the previous code example:

pub mod foo {
    pub const X: u32 = 1;
}

pub use foo as foo2;

fn main() {}

In this corrected example, the module foo is marked as public using the pub keyword, and as such, the pub use statement is no longer erroneous.

Further Tips and Recommendations

Keep in mind that if there are submodules with additional pub constants, structs, or enums, they need to be explicitly marked as public as well. For instance, if a submodule exists within foo called bar, it must be marked with the pub keyword for a successful public re-export.

Final Remarks

Understanding Rust Error E0365 is essential for effective code management. Remember to ensure that any modules or submodules being publicly re-exported have the necessary pub keyword attached. This will prevent the occurrence of E0365 errors and help create efficient, optimized code.