| % Macros |
| |
| <small>There is a new edition of the book and this is an old link.</small> |
| |
| > While functions and types abstract over code, macros abstract at a syntactic level. |
| |
| ```rust |
| macro_rules! five_times { |
| ($x:expr) => (5 * $x); |
| } |
| |
| fn main() { |
| assert_eq!(25, five_times!(2 + 3)); |
| } |
| ``` |
| |
| --- |
| |
| Here are the relevant sections in the new and old books: |
| |
| * **[In the current edition: Ch 19.06 Macros][2]** |
| * [Rust By Example: Macros][3] |
| * [In the Rust Reference: Ch 3.1 — Macros by Example][4] |
| * <small>[In the first edition: Ch 3.34 — Macros][1]</small> |
| |
| |
| [1]: https://doc.rust-lang.org/1.30.0/book/first-edition/macros.html |
| [2]: ch20-06-macros.html |
| [3]: https://rustbyexample.com/macros.html |
| [4]: ../reference/macros-by-example.html |
