c++ - Assigning value of global pointers -

#include <iostream>  int = 9; int *p; p = &a;  int fun();  int main() {     std::cout << fun();     return 0; }  int fun() {     return *p; } 

why code give error:

expected constructor, destructor, or type conversion before '=' token|

whereas code runs ok:

#include <iostream>  int = 9; int *p = &a;  int fun();  int main() {     std::cout << fun();     return 0; }  int fun() {     return *p; } 

you allowed declare , initialize variables/types globally not assign them.
main() start of c++ program , assign statements have inside main.

c++03 standard: section $3.6.1/1:

a program shall contain global function called main, designated start of program.

if coming scripting background, should note c++ different scripting languages in way can declare items outside bounds of designated start of program (main()), cannot processing(assignment or other statements).