In the previous section of this module, you learned how to create a new
cargo project, build, and
run it. This section will focus on the
[dependencies] section of your
Cargo.toml and how to
bring in external crates for usage within your project. Crates are other Rust packages with publicly
exposed types and functionality for usage in
Adding a new crate
Two primary methods of declaring an external crate in Rust are directly putting it in
or using the
We'll be importing the crate called
hex. It is a crate that easily
encodes and decodes data into hexadecimal representation.
Add this dependency as a key and value under
[dependencies], like so:
hex = "0.4"
The convention is the crate's name,
hex, followed by the version of the crate,
0.4. To ensure
everything is correctly in place without building the whole project, you may run
Checking hex v0.4.3
Checking first-cargo v0.1.0 (/rust-course/first-cargo)
Finished dev [unoptimized + debuginfo] target(s) in 0.70s
Using the cargo CLI
Optionally, you may also use the CLI to automate this by using
cargo add hex:
Updating crates.io index
Adding hex v0.4.3 to dependencies.
This will have the same effect as directly putting it within the TOML file.
For more information regarding Cargo and dependencies, visit the official Cargo documentation.