the problem of c++ encapsulation

[fanasy]

hi all,
I need help on c++ encapsulation
my code to test the encapsulation:

#include <iostream>
class test {
  private:
       void puts(std::string a);
};
void test::puts(std::string a){
   std::cout<<a;
}
int main(void){
 puts("hello ")
};

fanasymatoMacBook:Cpp zhongweidee$ ./a.out 
hello

1. why main function can access "private" puts member function?
2. how to avoid this access happen?
Thanks for your help

[firedraco]

You aren't accessing test::puts(), you are accessing the puts() function inside of cstdlib.

[fanasy]

thanks! my mistake.
happy new year!