Rust Quick Start Guide

Public and private module items

In many of the preceding examples, we saw a pub keyword. That keyword makes the item it's attached to public, meaning that it is available to code that is not part of the same module. If we omit the pub keyword on an item, that item is private, meaning that it can only be accessed within the module where it is defined. Private is the default, so we need to explicitly mark those items that we want to have as part of the module's externally accessible interface as public by using the pub keyword.

Making an item private is not a security mechanism. If you're worried that your code will be linked with hostile code that might misuse your code or data, making the code or data private will not protect against such ...