projects / rustc.git / blame
| Commit | Line | Data |
|---|---|---|
| 74b04a01 XL |
1 | # version\_check |
| 2 | ||
| 3 | [](https://travis-ci.com/SergioBenitez/version_check) | |
| 4 | [](https://crates.io/crates/version_check) | |
| 5 | [](https://docs.rs/version_check) | |
| 6 | ||
| 7 | This tiny crate checks that the running or installed `rustc` meets some version | |
| 8 | requirements. The version is queried by calling the Rust compiler with | |
| 9 | `--version`. The path to the compiler is determined first via the `RUSTC` | |
| 10 | environment variable. If it is not set, then `rustc` is used. If that fails, no | |
| 11 | determination is made, and calls return `None`. | |
| 12 | ||
| 13 | ## Usage | |
| 14 | ||
| 15 | Add to your `Cargo.toml` file, typically as a build dependency: | |
| 16 | ||
| 17 | ```toml | |
| 18 | [build-dependencies] | |
| 19 | version_check = "0.9" | |
| 20 | ``` | |
| 21 | ||
| 22 | `version_check` is compatible and compiles with Rust 1.0.0 and beyond. | |
| 23 | ||
| 24 | ## Examples | |
| 25 | ||
| 26 | Set a `cfg` flag in `build.rs` if the running compiler was determined to be | |
| 27 | at least version `1.13.0`: | |
| 28 | ||
| 29 | ```rust | |
| 30 | extern crate version_check as rustc; | |
| 31 | ||
| 32 | if rustc::is_min_version("1.13.0").unwrap_or(false) { | |
| 33 | println!("cargo:rustc-cfg=question_mark_operator"); | |
| 34 | } | |
| 35 | ``` | |
| 36 | ||
| 37 | Check that the running compiler was released on or after `2018-12-18`: | |
| 38 | ||
| 39 | ```rust | |
| 40 | extern crate version_check as rustc; | |
| 41 | ||
| 42 | match rustc::is_min_date("2018-12-18") { | |
| 43 | Some(true) => "Yep! It's recent!", | |
| 44 | Some(false) => "No, it's older.", | |
| 45 | None => "Couldn't determine the rustc version." | |
| 46 | }; | |
| 47 | ``` | |
| 48 | ||
| 49 | Check that the running compiler supports feature flags: | |
| 50 | ||
| 51 | ```rust | |
| 52 | extern crate version_check as rustc; | |
| 53 | ||
| 54 | match rustc::is_feature_flaggable() { | |
| 55 | Some(true) => "Yes! It's a dev or nightly release!", | |
| 56 | Some(false) => "No, it's stable or beta.", | |
| 57 | None => "Couldn't determine the rustc version." | |
| 58 | }; | |
| 59 | ``` | |
| 60 | ||
| 61 | See the [rustdocs](https://docs.rs/version_check) for more examples and complete | |
| 62 | documentation. | |
| 63 | ||
| 64 | ## Alternatives | |
| 65 | ||
| 66 | This crate is dead simple with no dependencies. If you need something more | |
| 67 | and don't care about panicking if the version cannot be obtained, or if you | |
| 68 | don't mind adding dependencies, see | |
| 69 | [rustc_version](https://crates.io/crates/rustc_version). | |
| 70 | ||
| 71 | ## License | |
| 72 | ||
| 73 | `version_check` is licensed under either of the following, at your option: | |
| 74 | ||
| 75 | * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0) | |
| 76 | * MIT License ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT) |