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Getting Started1

To run the sample ("Hello World") program:

$ cargo run --bin getting-started
   Compiling getting-started v0.1.0 ...
Hello World

Lessons Learned

Because of my sus decision to include every chapter in a monorepo, I had to spend a non-trivial amount of time configuring [workspace] settings and various Cargo.toml files before I could run a single line of code and have VSCode work.

Also, println! is a macro:

fn main() {
    println!("Hello World")
}

If you look at how this macro is implemented:

macro_rules! println {
    () => {
        $crate::print!("\n")
    };
    ($($arg:tt)*) => {{
        $crate::io::_print($crate::format_args_nl!($($arg)*));
    }};
}

Essentially:

  • If no arguments are provided, a new line is printed.
  • If one or more arguments are provided, they are formatted, and printed.

Footnotes

  1. Source: https://doc.rust-lang.org/book/ch01-00-getting-started.html ↩