2.18 Summary

In this chapter, we explored the basic structure and organization of Rust programs, highlighting both the similarities and differences with C. We covered:

  • Compilation and Cargo: How Rust compiles to an executable binary and how Cargo streamlines building and dependency management.
  • Program Structure: The default layout of Rust programs, including modules, functions, types, and use statements.
  • main Function: Rust’s entry point and its relationship to C’s main.
  • Variables and Mutability: Rust’s immutable-by-default approach, with the mut keyword for explicitly mutable variables.
  • Data Types: Fixed-width numeric types, booleans, and Rust’s Unicode-based char.
  • Constants and Statics: How to declare compile-time constants and static variables.
  • Functions and Control Flow: Defining functions, using if, while, for, and the loop construct.
  • Modules and Crates: Organizing code into modules and compiling it into either binary or library crates.
  • use and Namespacing: Precisely importing items into scope, in contrast to C’s preprocessor includes.
  • Traits: Abstracting shared behavior without using function pointers or manual vtables.
  • Macros: Safe, flexible compile-time code generation that goes beyond C’s macro system.
  • Error Handling: Employing Result and Option instead of exceptions or ambiguous error codes.
  • Memory Safety: Ownership and borrowing rules that prevent common memory issues at compile time.
  • Expressions vs. Statements: Rust’s expression-based syntax, which differs from C’s more rigid approach.
  • Style and Documentation: Naming conventions, formatting with rustfmt, and documentation via rustdoc.
  • Async Support: Rust’s async/await model and safe concurrency powered by crates like tokio.

Each of these elements contributes to Rust’s focus on safety, performance, and concurrency. Understanding them provides a solid foundation for more advanced topics such as ownership, lifetimes, and multi-threaded programming. The next chapters will delve deeper into these areas, illustrating how Rust’s unique features further distinguish it from C and other systems languages.