Crate version_check

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.

Example

Check that the running compiler is a nightly release:

extern crate version_check;

match version_check::is_nightly() {
    Some(true) => "running a nightly",
    Some(false) => "not nightly",
    None => "couldn't figure it out"
};

Check that the running compiler is at least version 1.13.0:

extern crate version_check;

match version_check::is_min_version("1.13.0") {
    Some((true, version)) => format!("Yes! It's: {}", version),
    Some((false, version)) => format!("No! {} is too old!", version),
    None => "couldn't figure it out".into()
};

Check that the running compiler was released on or after 2016-12-18:

extern crate version_check;

match version_check::is_min_date("2016-12-18") {
    Some((true, date)) => format!("Yes! It's: {}", date),
    Some((false, date)) => format!("No! {} is too long ago!", date),
    None => "couldn't figure it out".into()
};

Alternatives

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 adding dependencies, see rustc_version.

Functions

is_beta	Determines whether the running or installed rustc is on the beta channel.
is_dev	Determines whether the running or installed rustc is on the dev channel.
is_min_date	Checks that the running or installed rustc was released no earlier than some date.
is_min_version	Checks that the running or installed rustc is at least some minimum version.
is_nightly	Determines whether the running or installed rustc is on the nightly channel.
supports_features	Determines whether the running or installed rustc supports feature flags. In other words, if the channel is either "nightly" or "dev".