| Rustdoc will automatically scrape examples of documented items from a project's source code. These examples will be included within the generated documentation for that item. For example, if your library contains a public function: | |
| ```rust | |
| // src/lib.rs | |
| pub fn a_func() {} | |
| ``` | |
| And you have an example calling this function: | |
| ```rust | |
| // examples/ex.rs | |
| fn main() { | |
| a_crate::a_func(); | |
| } | |
| ``` | |
| Then this code snippet will be included in the documentation for `a_func`. | |
| ## How to read scraped examples | |
| Scraped examples are shown as blocks of code from a given file. The relevant item will be highlighted. If the file is larger than a couple lines, only a small window will be shown which you can expand by clicking ↕ in the top-right. If a file contains multiple instances of an item, you can use the ≺ and ≻ buttons to toggle through each instance. | |
| If there is more than one file that contains examples, then you should click "More examples" to see these examples. | |
| ## How Rustdoc scrapes examples | |
| When you run `cargo doc -Zunstable-options -Zrustdoc-scrape-examples`, Rustdoc will analyze all the documented crates for uses of documented items. Then Rustdoc will include the source code of these instances in the generated documentation. | |
| Rustdoc has a few techniques to ensure this doesn't overwhelm documentation readers, and that it doesn't blow up the page size: | |
| 1. For a given item, a maximum of 5 examples are included in the page. The remaining examples are just links to source code. | |
| 2. Only one example is shown by default, and the remaining examples are hidden behind a toggle. | |
| 3. For a given file that contains examples, only the item containing the examples will be included in the generated documentation. |