Package Management

Just like you use NuGet packages in .NET, Rust has its own package ecosystem called crates. Crates are managed by Cargo, Rust's package manager and build system (similar to how you use dotnet for .NET projects).

info

You can find a list of all available crates at crates.io

Here's how package management works in Rust:

Cargo.toml - This is similar to your .csproj file. It defines your project's metadata and dependencies:

[package]
name = "my_project"
version = "0.1.0"
edition = "2021"

[dependencies]
serde = { version = "1.0", features = ["derive"] }
tokio = { version = "1", features = ["full"] }

Adding dependencies - Instead of using the NuGet package manager UI, you can add dependencies directly to your Cargo.toml file or use the command line:
```
cargo add serde --features derive
```
Installing dependencies - When you run cargo build or cargo run for the first time, Cargo automatically downloads and compiles your dependencies.

Cargo is more than a package manager - it's a complete build system. It handles compiling your code, running tests, generating documentation, and more. As a .NET developer, you can think of it as combining the functionality of dotnet, NuGet, and MSBuild into a single tool.

Crate Features

Cargo “features” provide a mechanism to express conditional compilation and optional dependencies. A package defines a set of named features in the [features] table of Cargo.toml, and each feature can either be enabled or disabled.

If you're using a crate published by a 3rd party author you can specify the features you want to be enabled for a specific crate in the Cargo.toml file. The below enables the derive feature. Most crates enable a default set of features, which you can disable by setting default-features = false.

serde = { version = "1.0", features = ["derive"] }

This helps to ensure you only compile exactly the code you need when running your application is running in production. And don't worry, the compiler will tell you a dependency isn't found. Although the compiler can be rather unhelpful here by telling you a given struct/function doesn't exist. It can take some searching through the crate docs to find the required feature.

info

If you're authoring a crate, you can define the available features in your Cargo.toml file.

[features]
# Defines a feature named `webp` that does not enable any other features.
my_custom_feature = []

And then in your code you can define conditional compilation by adding the cfg(feature) attribute

#[cfg(feature = "my_custom_feature")]
pub mod webp;

Crate Features​

Crate Features