struct to 'set'

#include 
#include 
#include 
using namespace std;
struct A{
string str;
int score;
};
//assignable, copyable,comparable, struct A is not comparable
bool operator<(const A& lhs, const A& rhs) {
    return lhs.score<rhs.score;
}

void test(){
sets;
A a,b,c;
a.str="shanying";a.score=100;
b.str="shanying";b.score=0;
c.str="baitoudiao";c.score=50;

A cpy(a);
cout<<"orign:"<<a.str<<','<<a.score<<endl;
cout<<"copy:"<<cpy.str<<','<<cpy.score<<endl;

A assigned;
assigned = a;
cout<<"assigned:"<<assigned.str<<','<<assigned.score<<endl;

cout<<"a<b?"<<(a<b?"true":"false")<<endl;

s.insert(a);
s.insert(b);
s.insert(c);

cout<<"size:"<<s.size()<<endl;
}

int main() {
    test();

    return 0;
}