class object manipulation

HI, little help requested.

i am trying to select the members of a class object b1[i], by comparing
a member->value with and external value, and if the comparision is
true, then I would assign the entire b1[i] object to b2[i] object, after creating
a new book().

However I keep getting this error

Code:

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main.cxx: In function `int main(int, char**)':
main.cxx:107: error: no matching function for call to `book::setValues(book*&)'
book.h:15: error: candidates are: void book::setValues(book**)
book.h:17: error:                void book::setValues(std::basic_string<char,
  std::char_traits<char>, std::allocator<char> >, std::basic_string<char,
  std::char_traits<char>, std::allocator<char> >, std::basic_string<char,
  std::char_traits<char>, std::allocator<char> >, std::basic_string<char,
  std::char_traits<char>, std::allocator<char> >, std::basic_string<char,
  std::char_traits<char>, std::allocator<char> >, float)
make: *** [main.o] Error 1

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Im not sure if its the way im calling my constructor for this member function, becuase i havent used the & operator, only the ** types. Any help or suggestions are greatly appreciated.


main.cpp

Code:

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  float low,high;
  int nsize = 0;
  book *b2[VAL];
  for(int i = 0; i < size-1; i++) {
      if(b1[i]->getPrice() > low && b1[i]->getPrice() < high) {
        b2[i] = new book(title, author, publisher, month, year, price);

        b2[i]->setValues(b1[i]); // this line is causing ERROR.

        nsize++;
      }

---

book.h

Code:

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#include <string>
#include <fstream>

using namespace std;

class book {
  public:
      book(string,string,string,string,string,float);
      ~book();
      string getTitle() { return title; }
      string getAuthor() { return author; }
      string getPublisher() { return publisher; }
      string getMonth() { return month; }
      string getYear() { return year; }
      void setValues(book **b){}
      void setValues(string title, string author, string publisher,
                    string month, string year, float price);
      float getPrice() { return price; }
  private:
      string title;
      string author;
      string publisher;
      string month;
      string year;
      float price;
};

---

book.cpp

Code:

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#include "book.h"
#include <iostream>
#include <string>

using namespace std;
book::book( string title, string author, string publisher,
            string month, string year, float price) {}

void book::setValues(string title, string author, string publisher,
                    string month, string year, float price) {
  this->title=title; this->author=author; this->publisher=publisher;
  this->month=month; this->year=year; this->price=price;
}

void book::setValues(book **b) {
  b->title=this->title; b->author=this->author; b->publisher=this->publisher;
  b->month=this->month; b->year=this->year; b->price=this->price;
}

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You should be accepting a pointer to a book in your SetValues function, not a double pointer. Should be:

Code:

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void book::setValues(book *b)

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And in this case a copy constructor would work just as well. In fact, because all the members of your class are built-in types (like float) or have valid copy constructors themselves (like string), you don't even have to write a copy constructor, the default compiler generated one will work for you, so you can do this and remove the SetValues call:

Code:

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b2[i] = new book(*(b1[i]));

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Note that the extra * is to dereference the pointer since a copy constructor takes the object itself, not a pointer.

Yes, that does work... I tried that before, however it kept segfaulting.. I see now that the segfault occurs in display() and not in main();

Here is display, in case anyone sees an error, tiing is, this display function works fine when passed display(b1,size), (however no sorting), so im assuming my counting is wrong somewhere.;

Code:

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void display(book **b, int size); //constructor

display(b2,nsize);
void display(book **b, int size) {
  cout.precision(2);
  for(int i = 0; i < size-1; i++) {
  cout.setf(ios_base::left);
  cout << "|" << setw(25) << b[i]->getTitle().substr(0,25)
        << "|" << setw(20) << b[i]->getAuthor().substr(0,20)
        << "|" << setw(15) << b[i]->getPublisher().substr(0,15)
        << "|" << setw(3) << b[i]->getMonth() << "-" << setw(2) << b[i]->getYear()
        << "|" << " $" << setw(5) << b[i]->getPrice() << "|\n";
  }
}

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