Versions

Learn semver version specifiers and the cargo update command.

Versions

Crates use semantic versioning (semver): MAJOR.MINOR.PATCH. An incompatible change bumps MAJOR, a backward-compatible new feature MINOR, a bug fix PATCH. "1.2.3" in Cargo.toml actually means ^1.2.3:

"1.2.3"  = ^1.2.3   →  >=1.2.3, <2.0.0
"0.8"    = ^0.8     →  >=0.8.0, <0.9.0   (in 0.x, MINOR is breaking)
"~1.2"   →  >=1.2.0, <1.3.0
"=1.2.3" →  only 1.2.3

Tuple comparison

In Rust, tuples compare lexicographically: first elements first, then the seconds if equal... This makes comparing versions easy:

println!("{}", (1, 4, 0) > (1, 2, 3));   // true
println!("{}", (2, 0, 0) > (1, 9, 9));   // true

// the ^required rule (for MAJOR > 0)
fn uyumlu(gerekli: (u32, u32, u32), mevcut: (u32, u32, u32)) -> bool {
    mevcut.0 == gerekli.0 && mevcut >= gerekli
}

Exercise Compatibility check

Write the uyumlu function above. Print the results for versions (1, 4, 0), (2, 0, 0) and (1, 2, 1) against the requirement (1, 2, 3), separated by spaces.

Show example solution

fn uyumlu(gerekli: (u32, u32, u32), mevcut: (u32, u32, u32)) -> bool {
    mevcut.0 == gerekli.0 && mevcut >= gerekli
}

fn main() {
    let g = (1, 2, 3);
    println!("{} {} {}", uyumlu(g, (1, 4, 0)), uyumlu(g, (2, 0, 0)), uyumlu(g, (1, 2, 1)));
}

Test yourself

Does the dependency <code>rand = "0.8"</code> pick up version 0.9.0 automatically?
- Only with cargo update
- Only in release
- No; in 0.x versions a MINOR bump counts as breaking
- Yes
Show answer

No; in 0.x versions a MINOR bump counts as breaking — Before 1.0 the API is considered unstable, so the caret rule works on the first non-zero component.

Exact version

serde = "____1.0.193"   # yalnızca bu sürüm

Show answer

serde = "=1.0.193"   # yalnızca bu sürüm

Requirement and allowed range

"1.2.3"

>=1.2.3, <2.0.0
"0.8"

>=0.8.0, <0.9.0
"~1.2"

>=1.2.0, <1.3.0
"=1.2.3"

Only 1.2.3

Next lesson: Features

We Are Enhancing Your Experience

Cookie Preferences

Strictly Necessary Cookies

Analytical Cookies