def counter(statr_at = 0):

	count = 1

	def incr():

		nonlocal count #注意由于count类型为immutable，所以需要声明清楚在此局部作用域内引用的是外部作用域那个count

		count += 1

		return count

	return incr

>>> count = counter(4)

>>> count()

2

>>> count()

3

>>> count()

4

>>> count()

5

>>> count()

6

>>> count()

7

>>> count()

8

>>> count()

9

>>> count()

10

>>> count()

11

#include<iostream>

#include<memory>

using namespace std;

class Count{

public:

 Count(const shared_ptr<int>& p) :sp(p){}

 int operator()(){

  (*sp)++;

  return (*sp);

 }

private:

 shared_ptr<int> sp;

};

Count func(int k){

 shared_ptr<int> sp = make_shared<int>(k);

 return Count(sp);

}

int main(){

  auto c = func(10);

  cout << c() << endl;

  cout << c() << endl;

  cout << c() << endl;

 return 0;

}