Question 5 Given an arbitrary definition of a class named Object as abstract dat

Question

Question 5

Given an arbitrary definition of a class named Object as abstract data type - if a designer wanted to use an associative container like an std::map of the form std::map< Object, int* > - state and explain what important property must be defined for the class Object for it to be usable in the std::map as shown.

Question 6

State what are the 2 problems in the following code (2pts)

Provide a solution for each problem so that the code compiles and runs correctly by adding to this code (3pts)

// ----------------- Quiz question ----------------

#include <iostream>
#include <set>
#include <string>
#include <ctime>

using std::string;

class Employee
{
public:
    Employee(const int& n) : m_eid(n) {}
    ~Employee() {}
    int getEmpId() const
    {
        return m_eid;
    }
private:
    int m_eid;
};

int main(int argc, char* argv[])
{
    using std::cout;
    using std::endl;
    using std::set;

    set mySet;
    srand(time(NULL));

    unsigned int x = 0;
    while (x < 1000)
    {
        Employee emp( rand() % 1000 + 1 );
        mySet.insert( emp );
        x++;
    }
   
    return 0;
}

Explanation / Answer

Q5)

You have to define operator< for your class or
You can also make a comparator function object class for it, and use that to specialize std::map. To extend your example:

Q6.
   // ERROR: use of class template 'set' requires template arguments
//set mySet;
set<Employee> mySet;

// ERROR: to add an user defined Object in Set, you need to oveload operator<
mySet.insert( emp );

bool operator< (const Employee &left, const Employee &right){
       return left.getEmpId() < right.getEmpId();
       }

// ----------------- Quiz question ----------------
#include <iostream>
#include <set>
#include <string>
#include <ctime>

using std::string;

class Employee
{
public:
Employee(const int& n) : m_eid(n) {}
friend bool operator< (const Employee &left, const Employee &right);
~Employee() {}
int getEmpId() const
{
return m_eid;
}
private:
int m_eid;
};

bool operator< (const Employee &left, const Employee &right){
return left.getEmpId() < right.getEmpId();
}

int main(int argc, char* argv[])
{
using std::cout;
using std::endl;
using std::set;

// ERROR: use of class template 'set' requires template arguments
//set mySet;
set<Employee> mySet;

srand(time(NULL));

unsigned int x = 0;
while (x < 1000)
{
Employee emp(rand() % 1000 + 1 );
// ERROR: to add an user defined Object in Set, you need to oveload operator<
mySet.insert( emp );
x++;
}

return 0;
}

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