"no matching function" call error when using push_back on custom type

Question

I get this error when trying to push back an object of custom type. code follows:

class Item_base    
{
    public:     
    Item_base(string isbn=" ", int num=0):book(isbn),number(num){}    
    Item_base(Item_base &I):book(I.book),number(I.number){cout<<"\nCopy Constructor"<<endl;}    
    Item_base &operator=(Item_base &d){if (this != &d){this->book=d.book;this->number=d.number;cout<<"\nAssignment Operator"<<endl;return *this;}else{cout<<"\nAssignment Operator"<<endl;return *this;}}    
    ~Item_base(){cout<<"Item_base Destructor"<<endl;}   
    protected:    
    string book;     
    int number;    
};


#include <iostream>   
using namespace std;
#include <vector>
#include "Item_base.h"
int main (int argc, char * const argv[]) {    
    // insert code here...    
    vector<Item_base> vecbase;     
    Item_base derivo("Harry Potter",10);     
    cout<<"enter book name, qty, dqty"<<endl;     
    vecbase.push_back(derivo);     
    return 0;   
}

The error message i get is:

error: no matching function for call to 'Item_base::Item_base(const Item_base&)'

Can someone help me with this? I am new to programming

score 5 · Answer 1 · edited Oct 14 '12 at 10:05

5

Vector has only two implementations of push_back function

push_back(const T&)
push_back(T&&) (since C++11)

This explains, why we need to provide copy constructor with parameter const T& for our class

edited Oct 14 '12 at 10:05

juanchopanza

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answered Oct 14 '12 at 09:42

awesoon

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Thank you very much it worked. Does this mean push_back invokes the copy constructor? – Azeruddin Sheikh Azeemuddin Sh Oct 14 '12 at 09:48
@JohannesSchaub-litb, because vector has only two overloading of function push_back - with parameters `const T&` and `T&&`(since C++11). – awesoon Oct 14 '12 at 09:52
@AzeruddinSheikhAzeemuddinSh, yes, it does – awesoon Oct 14 '12 at 09:54
2

I think Johannes' point is that it is quite useful to include the explanation in the answer. It would certainly make this answer much better. – juanchopanza Oct 14 '12 at 09:56

"no matching function" call error when using push_back on custom type

1 Answers1