Rust attributes can generate trait implementations, request C-compatible struct representation, and enable compiler warnings. section 4.4.2 section 4.8 section 2.8
Use attributes for distinct implementation needs:
- `#[derive(...)]` generates trait implementations. For `HashMap` keys, derive `Hash` and `Eq`; `Eq` also requires `PartialEq`. `Debug` can help with debugging and tests. section 4.4.2
- `#[repr(C)]` requests a C-compatible struct representation for FFI. Use C types from `libc`; `rust-bindgen` can generate bindings from C headers. section 4.8
- `#![warn(missing_docs)]` enables a compiler warning for missing documentation; `cargo doc` generates the project documentation. section 2.8
Listing 4.10 Code listing for a compound key type
#[derive(Hash, Eq, PartialEq, Debug)]
struct CompoundKey {
name: String,
value: i32,
}
See a compound struct deriving `Hash`, `Eq`, `PartialEq`, and `Debug`. section 4.4.2
#[repr(C)] #1
struct GzFileState { #2
have: c_uint,
next: *mut c_uchar,
pos: i64,
}
See a C-compatible Rust struct using `#[repr(C)]` and C-mapped field types. section 4.8
