Crate rustc_version

Simple library for getting the version information of a rustc compiler.

This can be used by build scripts or other tools dealing with Rust sources to make decisions based on the version of the compiler.

It calls $RUSTC --version -v and parses the output, falling back to rustc if $RUSTC is not set.

Example

// This could be a cargo build script

extern crate rustc_version;
use rustc_version::{version, version_meta, Channel, Version};

fn main() {
    // Assert we haven't travelled back in time
    assert!(version().unwrap().major >= 1);

    // Set cfg flags depending on release channel
    match version_meta().unwrap().channel {
        Channel::Stable => {
            println!("cargo:rustc-cfg=RUSTC_IS_STABLE");
        }
        Channel::Beta => {
            println!("cargo:rustc-cfg=RUSTC_IS_BETA");
        }
        Channel::Nightly => {
            println!("cargo:rustc-cfg=RUSTC_IS_NIGHTLY");
        }
        Channel::Dev => {
            println!("cargo:rustc-cfg=RUSTC_IS_DEV");
        }
    }

    // Check for a minimum version
    if version().unwrap() >= Version::parse("1.4.0").unwrap() {
        println!("cargo:rustc-cfg=compiler_has_important_bugfix");
    }
}

Structs

• Version
  Represents a version number conforming to the semantic versioning scheme.
• VersionMeta
  Rustc version plus metada like git short hash and build date.

Enums

• Channel
  Release channel of the compiler.
• Error
  The error type for this crate.

Functions

• version
  Returns the rustc SemVer version.
• version_meta
  Returns the rustc SemVer version and additional metadata like the git short hash and build date.
• version_meta_for
  Parses a “rustc -vV” output string and returns the SemVer version and additional metadata like the git short hash and build date.

Type Aliases

• Result
  The result type for this crate.