Rust

15.2    Capturing Types

Captures were introduced briefly in the previous section. In this section, we explore it in greater detail. We’ll start with a special form of capture, called type capture, and then we’ll move on to identifier capture.

15.2.1    Type Capture

A type capture refers to a macro pattern that matches and captures a type, allowing the macro to use it dynamically within its expanded code. It is denoted by $name:ty where $name is the variable capturing the type and ty indicates that the capture is specifically for types. Let’s go through a user input taking example.

Recall from Chapter 3 that handling user input in Rust requires writing several lines of code, which can feel cumbersome for users accustomed to simpler syntax in ...