Conventions used

There are a number of text conventions used throughout this book.

CodeInText: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: "The reason is that the passing_through variable outlives x."

A block of code is set as follows:

fn my_function() {
    let x = 10;
    do_something(x); // ownership is moved here
    let y = x; // x is now invalid!
}

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

fn main() { 
    let mut a = 42; 
    let b = &a; // borrow a 
    let c = &mut a; // borrow a again, mutably 
    // ... but don't ever use b
}

Any command-line input or output is written as follows:

$ cargo test 

Bold: Indicates a new term, an important word, or words that you see onscreen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "Select System info from the Administration panel."