# cfg-if [Documentation](https://docs.rs/cfg-if) A macro to ergonomically define an item depending on a large number of #[cfg] parameters. Structured like an if-else chain, the first matching branch is the item that gets emitted. ```toml [dependencies] cfg-if = "0.1" ``` ## Example ```rust cfg_if::cfg_if! { if #[cfg(unix)] { fn foo() { /* unix specific functionality */ } } else if #[cfg(target_pointer_width = "32")] { fn foo() { /* non-unix, 32-bit functionality */ } } else { fn foo() { /* fallback implementation */ } } } fn main() { foo(); } ``` # License This project is licensed under either of * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0) * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT) at your option. ### Contribution Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in `cfg-if` by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.