# Project setup
cargo new my-project      # Binary crate
cargo new my-lib --lib    # Library crate
cargo init                # Initialize in existing directory

# Development workflow
cargo build                      # Debug build
cargo build --release           # Optimized build
cargo run                       # Build and run
cargo run --release             # Run optimized
cargo test                      # Run all tests
cargo test --lib               # Library tests only
cargo bench                     # Run benchmarks

# Code quality
cargo clippy                    # Lint code
cargo clippy -- -W clippy::pedantic  # Stricter lints
cargo fmt                       # Format code
cargo fmt --check              # Check formatting
cargo fix                       # Auto-fix warnings

# Dependencies
cargo add serde --features derive  # Add dependency
cargo update                       # Update deps
cargo audit                        # Security audit
cargo deny check                   # License/advisory check

# Advanced tools
cargo expand                    # Macro expansion
cargo flamegraph               # Profile with flame graph
cargo doc --open               # Generate and open docs
cargo miri test                # Check for UB

# Cross-compilation
rustup target add wasm32-unknown-unknown
cargo build --target wasm32-unknown-unknown

// Use iterators over manual loops
let sum: i32 = numbers.iter().filter(|x| **x > 0).sum();

// Prefer combinators for Option/Result
let value = config.get("key")
    .and_then(|v| v.parse().ok())
    .unwrap_or_default();

// Use pattern matching effectively
match result {
    Ok(value) if value > 0 => process(value),
    Ok(_) => handle_zero(),
    Err(e) => return Err(e.into()),
}

// Let-else for early returns
let Some(config) = load_config() else {
    return Err(ConfigError::NotFound);
};

my-project/
├── Cargo.toml
├── src/
│   ├── lib.rs        # Library root
│   ├── main.rs       # Binary entry point
│   ├── error.rs      # Error types
│   └── modules/
│       └── mod.rs
├── tests/            # Integration tests
├── benches/          # Benchmarks
└── examples/         # Example programs

use thiserror::Error;

#[derive(Error, Debug)]
pub enum AppError {
    #[error("IO error: {0}")]
    Io(#[from] std::io::Error),

    #[error("parse error: {message}")]
    Parse { message: String },

    #[error("not found: {0}")]
    NotFound(String),
}

pub type Result<T> = std::result::Result<T, AppError>;