Question

编译提示：error C2593: 'operator >' is ambiguous

#include<iostream>
#include<string>
using namespace std;
class String
{
public:
String (){
p=NULL;
}
String(char *p);
void display();
friend bool operator >(String&string1,String&string2);
//private:
char *p;

};
int main()
{
void compare(String&string1,String&string2);
String string1("hello"),string2("book");
compare(string1,string2);

// cout<<(string1>string2)<<endl;

return 0;

}
bool operator >(String&string1,String&string2)
{
if(strcmp(string1.p,string2.p)>0)
return true;
else return false;
}
String::String(char *str)
{
p=str;

}
void String::display()
{
cout<<p;
}
void compare(String&string1,String&string2)
{
if((string1>string2)==1)
{
string1.display();
cout<<">"<<endl;
string2.display();
}
else
cout<<"false"<<endl;
}

提示错误：

Answer 1

说操作符 > 具有双义性，不能用
比较俩string用 strcmp啊！