Question

C++出错.请高手指点 友元函数问题

这是我的源代码
总是有一个错误 ，请高手指点
#include<iostream>
using namespace std;
class Car;
class Boat
{
public:
Boat(float a=0){weight=a;}
SetWeight(float a){weight=a;}
friend float totalweight(Boat &x,Car &y);
private:
float weight;
};
class Car
{
public:
Car(float b=0){weight=b;}
SetWeight(float b){weight=b;}
friend float totalweight(Boat &x,Car &y);
private:
float weight;
};
float totalweight(Boat &x,Car &y)
{
return x.weight+y.weight;

}
void main()
{
Boat b(10);
Car c;
float sum;
c.SetWeight(15);
sum=totalweight(b,c);
cout<<"totalweight="<<sum<<endl;
}

Answer 1

SetWeight(float a){weight=a;} 这个函数没写返回类型

两个类里的这个都没写

Answer 2

啥子错哦?我拷贝过来放到VC6里编译和运行都没错啊.