Wrap Up

Using the macros is simple, coding efficient and tidy. Part of this, is the ability to have a variable number of parameters. As a Java programmer, this is something that I miss! In Rust, functions/methods don’t have this option. As you will see with Methods, this needs to be handled differently.

In this example, you’ve seen macros with:

• no parameters (entering!() and exiting()),
• a single &str (fine!("Bit more detail.")),
• a single &str with an interpolated variable (info!("Did some work here.\n {result}")),
• multiple parameters (warning!("Error: {}", e))
  I understand that this could have been interpolated, but it is shown here as an example of the ability to emulate macros like format!().