#include<bits/stdc++.h>
#include<conio.h>
#include<windows.h>
#include<io.h>
using namespace std;
class A{
	public:
		int a;
};
class B{
	public:
		int a;
};
operator>(const A& a,const B& b){
	return 9;
}
int main(){
	A c;B d;
	cout<<(c>d);
	return 0;
}

9

Process exited after 0.5311 seconds with return value 0 请按任意键继续. . .

就是说，重载运算符的返回值不是$bool$？