Rust Closures: Capture Your Environment for Efficient Code

Closures in Rust are anonymous functions that capture their environment, enabling you to access variables from the surrounding scope. They are flexible and powerful, allowing for compact and expressive code. Closures are defined using the vertical pipes (||) with optional arguments, followed by a code block. Rust closures also have type inference and automatic borrowing, making them ideal for various use cases such as higher-order functions and iterators.

In this example, we define a function execute that takes a closure as an argument. The closure greet captures the text variable from the surrounding scope and prints it, then sleeps for 2 seconds before printing a completion message. The execute function is then called with the greet closure, and the program waits for 3 seconds before displaying a final message.