クロージャー(Golang and Rust)

package main

import "fmt"

func add(i int) func() int {
	n := i

	clo := func() int {
		n++
		return n
	}

	return clo		// equivalent to specify anonymous function here and maybe it's more popular
}

func main() {
	a := add(1)
	for i := 1; i < 10; i++ {
		fmt.Println(a())
	}
}

fn f1(i: i32) -> Box<dyn FnMut -> i32> {	// FnMut recieves &mut self
	let mut i = i;						// dyn keyword sepcifies a trait pointer in the heap area
	Box::new(move || {				// force to allocate values in the heap area
		i += 1;
		i
	})
 }
 
 fn main() {
	 let mut cup = f1(0);
	 for _ in 1..10 {
		 println!("{}", cup());
	 }
 }