#include <iostream>
using namespace std;

class File_ptr {
FILE *p;
public:
File_ptr (const char* n, const char* a) { p=fopen(n,a); }
File_ptr (FILE *pp) {p=pp;}
~File_ptr() {fclose(p);}

operator FILE* () {return p;}
};


void use_file(const char* fn)
{
File_ptr f(fn,"r");
// file will be closed when fn goes out of scope
// ...
}


int main(int argc, char* argv[])
{
use_file("foo");
return 0;

}