Cargo 教程
Cargo.toml、依赖管理、features、workspace、以及常用命令。
Key PointsCargo 同时是构建工具、包管理器、测试运行器和文档生成器。
项目结构
Text
hello/
├── Cargo.toml ← 项目清单
├── Cargo.lock ← 精确版本锁（可执行程序要提交）
├── src/
│ ├── main.rs ← 二进制入口
│ └── lib.rs ← 库入口
├── tests/ ← 集成测试
├── benches/ ← 基准测试
└── examples/ ← 示例Cargo.toml
TOML
[package]
name = "hello"
version = "0.1.0"
edition = "2021"
authors = ["Your Name <you@example.com>"]
description = "一个示例项目"
license = "MIT"
[dependencies]
serde = { version = "1.0", features = ["derive"] }
tokio = { version = "1", features = ["full"] }
[dev-dependencies]
criterion = "0.5"
[profile.release]
opt-level = 3
lto = true
strip = true
[[bin]]
name = "hello"
path = "src/main.rs"常用命令
Bash
cargo new myapp # 新建二进制项目
cargo new mylib --lib # 新建库项目
cargo build # 调试构建
cargo build --release # 优化构建
cargo run # 构建并运行
cargo test # 跑测试
cargo doc --open # 生成并打开文档
cargo fmt # 格式化
cargo clippy # 静态检查
cargo add serde # 加依赖（1.62+ 内置）
cargo update # 升级到兼容的最新版
cargo tree # 依赖树
cargo clean # 清 target/Output
$ cargo add serde --features derive
Adding serde v1.0.215 to dependencies
Features:
+ derivefeatures
TOML
[dependencies]
reqwest = { version = "0.12", default-features = false, features = ["json", "rustls-tls"] }default-features = false disables defaults so you enable only what you need. This matters a lot for build time and binary size — reqwest defaults to OpenSSL; rustls-tls avoids the system dependency.
workspace
TOML
# 根 Cargo.toml
[workspace]
members = ["crates/api", "crates/core", "crates/cli"]
resolver = "2"
[workspace.dependencies]
serde = { version = "1.0", features = ["derive"] }
tokio = { version = "1", features = ["full"] }TOML
# crates/api/Cargo.toml
[dependencies]
serde = { workspace = true }
tokio = { workspace = true }
core = { path = "../core" }A workspace shares one target/ and one set of dependency versions, so builds are faster and versions cannot diverge. workspace.dependencies is the single place for versions.
测试与文档
Rust
// src/lib.rs
/// 两数相加。
///
/// # 示例
///
/// ```
/// assert_eq!(add(1, 2), 3);
/// ```
pub fn add(a: i32, b: i32) -> i32 {
a + b
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn it_works() {
assert_eq!(add(2, 2), 4);
}
}Output
$ cargo test
running 1 test
test tests::it_works ... ok
test result: ok. 1 passed; 0 failed; 0 ignoredCode blocks in doc comments are **executed by cargo test**, so examples cannot rot. That is why Rust documentation is unusually trustworthy.
项目结构
Text
hello/
├── Cargo.toml ← 项目清单
├── Cargo.lock ← 精确版本锁（可执行程序要提交）
├── src/
│ ├── main.rs ← 二进制入口
│ └── lib.rs ← 库入口
├── tests/ ← 集成测试
├── benches/ ← 基准测试
└── examples/ ← 示例Cargo.toml
TOML
[package]
name = "hello"
version = "0.1.0"
edition = "2021"
authors = ["Your Name <you@example.com>"]
description = "一个示例项目"
license = "MIT"
[dependencies]
serde = { version = "1.0", features = ["derive"] }
tokio = { version = "1", features = ["full"] }
[dev-dependencies]
criterion = "0.5"
[profile.release]
opt-level = 3
lto = true
strip = true
[[bin]]
name = "hello"
path = "src/main.rs"常用命令
Bash
cargo new myapp # 新建二进制项目
cargo new mylib --lib # 新建库项目
cargo build # 调试构建
cargo build --release # 优化构建
cargo run # 构建并运行
cargo test # 跑测试
cargo doc --open # 生成并打开文档
cargo fmt # 格式化
cargo clippy # 静态检查
cargo add serde # 加依赖（1.62+ 内置）
cargo update # 升级到兼容的最新版
cargo tree # 依赖树
cargo clean # 清 target/Output
$ cargo add serde --features derive
Adding serde v1.0.215 to dependencies
Features:
+ derivefeatures
TOML
[dependencies]
reqwest = { version = "0.12", default-features = false, features = ["json", "rustls-tls"] }default-features = false 关掉默认特性，只开你要的。这对编译时间和二进制体积影响很大——reqwest 默认会带上 OpenSSL，换成 rustls-tls 就不用系统装 OpenSSL。
workspace
TOML
# 根 Cargo.toml
[workspace]
members = ["crates/api", "crates/core", "crates/cli"]
resolver = "2"
[workspace.dependencies]
serde = { version = "1.0", features = ["derive"] }
tokio = { version = "1", features = ["full"] }TOML
# crates/api/Cargo.toml
[dependencies]
serde = { workspace = true }
tokio = { workspace = true }
core = { path = "../core" }workspace 让多个 crate 共享一份 target/ 和一份依赖版本，编译更快、版本不会冲突。workspace.dependencies 是统一版本号的地方。
测试与文档
Rust
// src/lib.rs
/// 两数相加。
///
/// # 示例
///
/// ```
/// assert_eq!(add(1, 2), 3);
/// ```
pub fn add(a: i32, b: i32) -> i32 {
a + b
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn it_works() {
assert_eq!(add(2, 2), 4);
}
}Output
$ cargo test
running 1 test
test tests::it_works ... ok
test result: ok. 1 passed; 0 failed; 0 ignored文档注释里的代码块会被 cargo test 当作测试执行。这保证示例不会随代码演进而失效——Rust 生态里文档可信度高，原因就在这里。