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