This tiny crate checks that the running or installed rustc
meets some version requirements. The version is queried by calling the Rust compiler with --version
. The path to the compiler is determined first via the RUSTC
environment variable. If it is not set, then rustc
is used. If that fails, no determination is made, and calls return None
.
Add to your Cargo.toml
file, typically as a build dependency:
[build-dependencies] version_check = "0.9"
version_check
is compatible and compiles with Rust 1.0.0 and beyond.
Set a cfg
flag in build.rs
if the running compiler was determined to be at least version 1.13.0
:
extern crate version_check as rustc; if rustc::is_min_version("1.13.0").unwrap_or(false) { println!("cargo:rustc-cfg=question_mark_operator"); }
Check that the running compiler was released on or after 2018-12-18
:
extern crate version_check as rustc; match rustc::is_min_date("2018-12-18") { Some(true) => "Yep! It's recent!", Some(false) => "No, it's older.", None => "Couldn't determine the rustc version." };
Check that the running compiler supports feature flags:
extern crate version_check as rustc; match rustc::is_feature_flaggable() { Some(true) => "Yes! It's a dev or nightly release!", Some(false) => "No, it's stable or beta.", None => "Couldn't determine the rustc version." };
See the rustdocs for more examples and complete documentation.
This crate is dead simple with no dependencies. If you need something more and don‘t care about panicking if the version cannot be obtained, or if you don’t mind adding dependencies, see rustc_version.
version_check
is licensed under either of the following, at your option: