CodeBlanks Logo Icon CodeBlanks
Login Register

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
}

Practice 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.

Starter code

main.rs
fn main() {
    // buraya yaz
}

Sample solution

main.rs
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)));
}

Expected output

true false false

Questions and answers

Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.

1 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 Correct answer
  • Yes

Explanation: Before 1.0 the API is considered unstable, so the caret rule works on the first non-zero component.

2 Exact version

Question 
serde = "____1.0.193"   # yalnızca bu sürüm
Answer 
serde = "=1.0.193"   # yalnızca bu sürüm

Explanation: The = prefix locks to a single version.

3 Requirement and allowed range

Term Meaning
"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

All lessons in Intermediate

1 Traits

  1. What is a trait?
  2. Implementing a trait
  3. Default methods
  4. Traits as parameters
  5. Multiple traits
  6. Summary - Traits

2 Generics

  1. Generic function
  2. Generic struct
  3. Generic method
  4. Generic enum
  5. Turbofish
  6. Summary - Generics

3 Lifetimes

  1. What is a lifetime?
  2. Explicit lifetimes
  3. Function lifetimes
  4. Struct lifetimes
  5. Elision rules
  6. Summary - Lifetimes

4 Trait bounds

  1. Trait bound
  2. Multiple bounds
  3. where clause
  4. impl Trait
  5. dyn Trait
  6. Summary - Trait bounds

5 Project: Library crate

  1. Crate skeleton
  2. Public API
  3. Generic structure
  4. Searching with traits
  5. Test infrastructure

6 Smart pointers

  1. Box<T>
  2. Rc<T>
  3. Arc<T>
  4. Box and recursion
  5. Deref
  6. Summary - Smart pointers

7 Interior mutability

  1. RefCell<T>
  2. borrow and borrow_mut
  3. Rc<RefCell<T>>
  4. Cell<T>
  5. External mutation
  6. Summary - Interior mutability

8 Closures

  1. Closure syntax
  2. Type inference
  3. Capturing
  4. Fn, FnMut, FnOnce
  5. Closure and iterator
  6. Summary - Closures

9 Iterators

  1. Iterator trait
  2. next method
  3. map and filter
  4. collect
  5. Lazy evaluation
  6. Summary - Iterators

10 Collections

  1. HashMap
  2. BTreeMap
  3. HashSet
  4. Entry API
  5. Iterating collections
  6. Summary - Collections

11 Project: CLI app

  1. Command skeleton
  2. State with Vec
  3. Result and commands
  4. Processing with iterators
  5. Error and exit

12 Advanced error handling

  1. Error trait
  2. thiserror
  3. anyhow
  4. Error conversion
  5. Adding context
  6. Summary - Advanced error handling

13 Modules

  1. Defining modules
  2. use
  3. pub
  4. File modules
  5. crate and super
  6. Summary - Modules

14 Crates and packages

  1. Binary and library crate
  2. Cargo.toml
  3. Versions
  4. Features
  5. Workspace
  6. Summary - Crates and packages

15 Testing

  1. Unit test
  2. assert! macro
  3. Integration test
  4. Doc test
  5. should_panic
  6. Summary - Testing

16 File I/O

  1. Reading a file
  2. Writing a file
  3. Append mode
  4. BufReader
  5. Directory operations
  6. Summary - File I/O

17 CLI with clap

  1. Introducing clap
  2. Derive macro
  3. Positional argument
  4. Option flag
  5. Subcommand
  6. Summary - CLI with clap

18 Serialization with serde

  1. Serialize and Deserialize
  2. derive
  3. JSON
  4. Field rename
  5. Option and default
  6. Summary - Serde

19 Project: Blog API

  1. Model skeleton
  2. Reading JSON
  3. Error handling
  4. Listing records
  5. CLI

20 Intermediate final

  1. Generic stack
  2. Shapes with traits
  3. Iterator adapter
  4. JSON config reader