PRfilebuf* rdbuf(){return (PRfilebuf*) ios::rdbuf(); }
PRfilebuf* rdbuf(){ return (PRfilebuf*) ostream::rdbuf(); }
class PR_IMPLEMENT(PRifstream): public istream {public:	PRifstream();	PRifstream(const char *, int mode=ios::in, int flags = 0);	PRifstream(PRFileDesc *);	PRifstream(PRFileDesc *, char *, int);	~PRifstream();	streambuf * setbuf(char *, int);	PRfilebuf* rdbuf(){return (PRfilebuf*) ios::rdbuf(); }	void attach(PRFileDesc *fd);	PRFileDesc *fd() {return rdbuf()->fd();}	int is_open(){return rdbuf()->is_open();}	void open(const char *, int mode=ios::in, int flags= 0);	void close();};