No matching Constructor Error For Initialization in c . Whats wrong with my constructor?-CodePudding

I have a class in a header file as follows:

#include <iostream>
#include <string>
#include <sstream>
using namespace std;
    class ShowTicket {
    public:
        bool is_sold(void){
            if (sold_status == true){
                return true;
            }
            else{
                return false;
            }
        }
        void sell_seat(void){
            sold_status = true;
        }
        string print_ticket(void){
            ostringstream sout;
            if(sold_status == true){
                sout<<row<<" "<<seat_number<<"sold";
            }
            else{
                sout<<row<<" "<<seat_number<<"available";
            }
            return sout.str();
        }
        bool sold_status;
        const char* row;
        const char* seat_number;

        ShowTicket(const char* Row, const char* SeatNumber):
        sold_status{false},
        row(Row),
        seat_number(SeatNumber)
        {}
    };

The main function to test this class is as follows:

#include <iostream>
#include <string>
#include <sstream>
#include "showticket.h"
using namespace std;

int main () {
    ShowTicket myticket1("AA","101");
    ShowTicket myticket2("AA","102");
  if(!myticket1.is_sold())
    myticket1.sell_seat ();
  cout << myticket1.print_ticket() << endl;
  cout << myticket2.print_ticket() << endl;
  return 0;
}

When myticket 1 and 2 are created there is an error "No matching constructor for initialization of 'ShowTicket" but I believe my constructor accepts these parameters so I'm not sure how to resolve.

Any advice would be appreciated.

CodePudding user response：

By the looks of it, you only want to supply two arguments, but your constructor requires three:

ShowTicket(const char* row, const char* seat_number, bool sold_status){
    sold_status = false;
}

The body of the constructor makes be believe that you want to initialize a newly created ShowTicket with sold_status set to false. You can do that directly in the member initializer list:

ShowTicket(const char* row, const char* seat_number) : // note the colon
    sold_status{false} // <- here
{}

If that's not the case, you can make sold_status have a default value, below it's set to false:

ShowTicket(const char* row, const char* seat_number, bool sold_status = false) :
    sold_status{sold_status} 
{}

I also recommend using different names for the arguments and the member variables. It can easily get messy otherwise:

ShowTicket(const char* row, const char* seat_number, bool SoldStatus = false) :
    sold_status{SoldStatus} 
{}

Also note that you don't actually allocate memory for and save the row and seat_number in the constructor. Calling your print_ticket function will therefore cause undefined behavior. I recommend that you replace the raw pointers and replace them with std::strings:

        std::string row;
        std::string seat_number;

You can now save all in the constructor and not have to worry about memory management:

ShowTicket(const char* Row, const char* SeatNumber, bool SoldStatus = false) :
    sold_status{SoldStatus},
    row(Row),
    seat_number(SeatNumber)
{}

You may also want to consider taking the row and seat_number arguments as const std::string&s or std::string_views (since C 17) to make it easier to work with in general.