newbie question:why does this code work...

[anagram]

hi all...
i found this code in some past discussion on this forum.i do not understand why operator overloading is necessary.if i remove it iam getting errors...

#include <map>

class Keys {
public:
Keys(int k1, int k2)  
{
      key1=k1;
      key2=k2;
 }
bool operator<(const Keys &right) const {
return (key1 < right.key1 && key2 < right.key2);
}
int key1;
int key2;
};

int main() {
std::map<Keys, int> mymap;
mymap.insert(std:air<Keys, int>(Keys(3, 8), 5));
return 0;
}

[weaknessforcats]

You are using a map of Keys objects. A map is a tree of ordered values. The map insert needs to know how to compare objects by calling the < operator to preserve the order.

[anagram]

i get the gist of what you say.....
but plzzzzz can u explain more about the ordering a lil bit.....
it would be very helpful....

[anagram]

thank you for the previous explanation...