Rust Closures and lambda expressions Simple closures
Example
Unlike regular functions, lambda expressions can capture their environments. Such lambdas are called closures.
// variable definition outside the lambda expression...
let lucky_number: usize = 663;
// but the our function can access it anyway, thanks to the closures
let print_lucky_number = || println!("{}", lucky_number);
// finally call the closure
print_lucky_number();
This will print:
663
