Rust Programming Cookbook

How it works...

Inside the main function, we now have a few macros that are more or less well known. Each of them is doing something we thought was useful. We'll skip step 2 since it only shows the println! macro—something that we are using constantly. In step 3, however, some more exotic macros turn up:

• vec! creates and initializes a vector and famously uses [] to do so. However, while this makes visual sense, the compiler will accept vec!() just as well as vec!{}.
• concat! joins literals from left to right like a static string.
• stringify! creates a string literal from the input tokens, regardless of whether they exist or not (see the word helloworld, which got translated to a string).

Step 4 includes working with a procedural macro in ...