Can't find Ostream

[herrgeothe]

some gentleman please tell me what's going on with my program??
in the String.h ,i will overload the operator <<.....

but something is wrong with the OSTREAM....can't find it....



#include <iostream>
using namespace std;

class String;
istream& operator>>(istream&, String&);
ostream& operator<<(ostream&,const String&);
class String{

//......something else;

public:
char* c_str(){ return _string;}
private:
_string;


};

//this is where the problem is....
inline ostream&
operator<<( ostream &os, String &s)
{
return os << s.c_str();
}

[vlad from moscow]

You declared operator << as

ostream& operator<<(ostream&,const String&);

but defined another overloaded operator << as

inline ostream&
operator<<( ostream &os, String &s)