set-lower_bound

////////////////////////////////////////
//      2018/04/28 19:23:07
//      set-lower_bound

// return an iterator to the first element greater than a certain value
#include <iostream>
#include <set>
#include <iomanip>
#include <string>

using namespace std;

template<class T>
class Member
{
private:
    T first, last;
public:
    Member(T l) :last(l), first(""){}
    Member(T l, T f) :last(l), first(f){}

    void print() const
    {
        cout.setf(ios::left);
        cout << setw(15) << first << " " << last << endl;
    }

    friend bool operator < (const Member& m1, const Member& m2){
        return m1.last < m2.last;
    }

    friend bool operator == (const Member& m1, const Member& m2){
        return m1.last == m2.last;
    }
};

//========================================

int main(){
    typedef Member<string> M;
    typedef set<M, less<M>> S;

    S s;

    s.insert(M("Smith", "Jhon"));
    s.insert(M("Shevchenko","Taras"));
    s.insert(M("Amstrong","Bill"));
    s.insert(M("Bain","Linda"));
    s.insert(M("Pushkin", "Alexander"));
    s.insert(M("Pasternak","Biris"));

    S::iterator it = s.begin();
    while (it != s.end()){
        (it++)->print();
    }
    cout << endl;

    M m1("P");
    M m2("Pzz");

    S::iterator low = s.lower_bound(m1);
    S::iterator upp = s.upper_bound(m2);
    it = low;

    while (it != upp){
        (it++)->print();
    }

    return 0;
}


/*
OUTPUT:
    Bill            Amstrong
    Linda           Bain
    Biris           Pasternak
    Alexander       Pushkin
    Taras           Shevchenko
    Jhon            Smith

    Biris           Pasternak
    Alexander       Pushkin
*/