Bug: 220164656

Clone this repo:
  1. 9c151fa Make semver available to product and vendor am: 4a4be7df28 by Matthew Maurer · 11 days ago master
  2. 4a4be7d Make semver available to product and vendor by Matthew Maurer · 13 days ago
  3. ca359f7 Update TEST_MAPPING am: 304d73376c by Jeff Vander Stoep · 7 weeks ago
  4. 304d733 Update TEST_MAPPING by Jeff Vander Stoep · 7 weeks ago
  5. e0b6f12 Update TEST_MAPPING am: 0e51d1d1f3 by David Brazdil · 8 weeks ago


A parser and evaluator for Cargo's flavor of Semantic Versioning.

Semantic Versioning (see https://semver.org) is a guideline for how version numbers are assigned and incremented. It is widely followed within the Cargo/crates.io ecosystem for Rust.

semver = "1.0"

Compiler support: requires rustc 1.31+


use semver::{BuildMetadata, Prerelease, Version, VersionReq};

fn main() {
    let req = VersionReq::parse(">=1.2.3, <1.8.0").unwrap();

    // Check whether this requirement matches version 1.2.3-alpha.1 (no)
    let version = Version {
        major: 1,
        minor: 2,
        patch: 3,
        pre: Prerelease::new("alpha.1").unwrap(),
        build: BuildMetadata::EMPTY,

    // Check whether it matches 1.3.0 (yes it does)
    let version = Version::parse("1.3.0").unwrap();

Scope of this crate

Besides Cargo, several other package ecosystems and package managers for other languages also use SemVer: RubyGems/Bundler for Ruby, npm for JavaScript, Composer for PHP, CocoaPods for Objective-C...

The semver crate is specifically intended to implement Cargo's interpretation of Semantic Versioning.

Where the various tools differ in their interpretation or implementation of the spec, this crate follows the implementation choices made by Cargo. If you are operating on version numbers from some other package ecosystem, you will want to use a different semver library which is appropriate to that ecosystem.

The extent of Cargo's SemVer support is documented in the Specifying Dependencies chapter of the Cargo reference.