match_cfg

Documentation

Minimum Supported Rust Version: 1.13.0.

A convenience macro to ergonomically define an item depending on a large number of #[cfg] parameters. Structured like match statement, the first matching branch is the item that gets emitted.

[dependencies]
match_cfg = "0.1"

The use_core feature is enabled by default and builds the crate with libcore as a dependency by using the #![no_std] attribute. When this feature is disabled, this crate is built without libcore support by using the #![no_core] attribute - this makes use of the #![feature(no_core)] and requires a nightly version of Rust.

Example

#[macro_use(match_cfg)]
extern crate match_cfg;

match_cfg! {
    #[cfg(unix)] => {
         fn foo() { /* unix specific functionality */ }
     }
     #[cfg(target_pointer_width = "32")] => {
         fn foo() { /* non-unix, 32-bit functionality */ }
     }
     _ => {
         fn foo() { /* fallback implementation */ }
     }
}

fn main() {
    foo();
}

License

This project is licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in Serde by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.