C++ error: trying to understand Classes and Constructors

user_10345359 0
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I am trying to understand the error I am receiving:

error: is implicitly deleted because the default definition would be ill-formed

Looking into why I am getting the error, I believe it has something to do with not having a default constructor for class Dealer. I'm not quite understanding why that is the case in regards to this program. I believe it has to do with the Motorcycle m_motorcycle object I created.

#include <iostream>
using namespace std;

class Motorcycle{

public:
    string m_make;
    string m_model;
    int m_year;
    Motorcycle(string, string, int);
};

class Dealer{
private:
    Motorcycle m_motorcycles[3];
public:
    void addMotorcycle(Motorcycle);
    Motorcycle getMotorcycle(int);
};

int main(){
    Motorcycle bike1("Ductai", "Scrambler", 2020);
    Dealer dealer1;

    dealer1.addMotorcycle(bike1);
    return 0;
}

Motorcycle::Motorcycle(string make, string model, int year){
  this->m_make = make;
  this->m_model = model;
  this->m_year = year;
}
void Dealer::addMotorcycle(Motorcycle bike){
    this->m_motorcycles[0] = bike;
}
c++
2 Answers

Initialization of Dealer requires initialization of Motorcycle m_motorcycles[3];, when it tries to create an array of Motorcycle it looks for its default constructor, but only a parameterized constructor is provided.

class Motorcycle{
public:
    string m_make;
    string m_model;
    int m_year;
    Motorcycle(string, string, int);
    Motorcycle(){ 
        //.....
    }; 
};

Adding a default constructor to Motorcycle would be one way of fixing it.

user_114284590

The error is saying that implicit default constructor of class Dealer is deleted since it contains Motorcycle m_motorcycles[3];, and Motorcycle has no default constructor.

A way to solve this is to include std::vector<Motorcycle> m_motorcycles; in class Dealer instead of the array, and also change Dealer::addMotorcycle():

void Dealer::addMotorcycle(Motorcycle bike){
    this->m_motorcycles.push_back( bike );
}
user_4595650
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