question about C++ STL set

[jagadish]

i am trying to make a set of objects of type two and go like this :

Code: Select all

struct two {
   int     a,b;
};
int main(){
    set<two> a ;
    two t;
    t.a=1; t.b=3;
    a.insert(t);
    set<two>::iterator  i;
    for(i=a.begin() ; i!=a.end() ; i++)
        cout << a[i].a << a[i].b ;
    return 0;
}
 

i get error message at a.insert(t) which i'm not able to comprehend.... plz give me the correct idea to implement this.

[Krzysztof Duleba]

You have to specify a comparator. For instance, you can define operator< in class two.

You could also use std::pair instead of two. Here it would look like

Code: Select all

set<pair<int,int> > a;
a.insert(pair<int,int>(1,3));