关于友员函数
#include <iostream>
using namespace std;
class Score
{
friend ostream & operator<<(ostream & os, const Score & s);
private:
unsigned int num;
public:
Score():num(0){};
};
ostream & operator<<(ostream & os, const Score & s)
{
os<<s.num;
return os;
}
为什么在VC6.0下出现如下错误:
--------------------Configuration: test - Win32 Debug--------------------
Compiling...
score.cpp
C:\PROGRAM FILES\MICROSOFT VISUAL STUDIO\MYPROJECTS\test\score.cpp(17) : error C2248: 'num' : cannot access private member declared in class 'Score'
C:\PROGRAM FILES\MICROSOFT VISUAL STUDIO\MYPROJECTS\test\score.cpp(8) : see declaration of 'num'
Error executing cl.exe.
score.obj - 1 error(s), 0 warning(s)