Rust Declarative Macros (`macro_rules!`)
Think of `macro_rules!` as 'find and replace' for your code's structure. It matches patterns at compile time and expands them into boilerplate you don't want to write. It's used for helpers like `vec![]`.
Think of `macro_rules!` as a `match` statement for your code's structure. It lets you write code that writes other code by matching patterns at compile time and expanding them into boilerplate. This is how Rust creates helpers like `vec![1, 2]` and `assert_eq!`. It's ideal for reducing repetition or creating a mini-language (DSL). The biggest footgun is debugging: compiler errors often point to the generated code, not your original macro invocation, leading to confusing messages.
Read the original → doc.rust-lang.org
- #rust
- #metaprogramming
- #macros
- #dsl
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