19.5 SetContactsList.cpp

#include <set>
#include <iostream>
#include <string>
using namespace std;
   
template <typename T>
void DisplayContents(const T& container)
{
   for(auto iElement = container.cbegin();
         iElement != container.cend();
         ++ iElement)
      cout << *iElement << endl;

   cout << endl;
}

struct ContactItem
{
   string name;
   string phoneNum; 
   string displayAs;

   ContactItem(const string& nameInit, const string & phone)
   {
      name = nameInit;
      phoneNum = phone;
      displayAs =(name + ": " + phoneNum);
   }

   // used by set::find() given contact list item
   bool operator ==(const ContactItem& itemToCompare) const
   {
      return(itemToCompare.name == this->name);
   }

   // used to sort
   bool operator <(const ContactItem& itemToCompare) const
   {
      return(this->name < itemToCompare.name);
   }

   // Used in DisplayContents via cout
   operator const char*() const
   {
      return displayAs.c_str();
   }
};

int main()
{
   set<ContactItem> setContacts;
   setContacts.insert(ContactItem("Oprah Winfrey", "+1 7889 879 879"));
   setContacts.insert(ContactItem("Bill Gates", "+1 97 7897 8799 8"));
   setContacts.insert(ContactItem("Angi Merkel", "+49 23456 5466"));
   setContacts.insert(ContactItem("Vlad Putin", "+7 6645 4564 797"));
   setContacts.insert(ContactItem("John Travolta", "91 234 4564 789"));
   setContacts.insert(ContactItem("Angelina Jolie", "+1 745 641 314"));
   DisplayContents(setContacts);

   cout << "Enter a name you wish to delete: ";
   string inputName;
   getline(cin, inputName);

   auto contactFound = setContacts.find(ContactItem(inputName, ""));
   if(contactFound != setContacts.end())
   {
      setContacts.erase(contactFound);
      cout << "Displaying contents after erasing " << inputName << endl;
      DisplayContents(setContacts);
   }
   else
      cout << "Contact not found" << endl;

   return 0;
}