error with functions returning functions

[Atybot]

function func1(arg1, arg2) {
  return function nestedfunc() {
    return arg1 + arg2;
  };
}

console.log(func1(1, 2)());

[HotoRas]

You could do it with external struct defines as static in c:

#include <stdio.h>

struct Template { int a1; int a2; };

static struct Template temp;

int nestedfunc(void) {
    return temp.a1 + temp.a2;
}

int* (* func1(int arg1, int arg2))(void) {
    temp.a1 = arg1; temp.a2 = arg2;
    return (int* (*) (void)) nestedfunc;
}

int main() {
    temp.a1 = 0; temp.a2 = 0;

    printf("%d\n", func1(1, 2)());
    return 0;
}

However, it's unable in ISO C/C++ to directly nest functions- it's GCC/G++ feature.