Inheritance: No appropriate default constructor available - c++

Question

I get the error: No appropriate default constructor for B. However, I don't understand why the compiler wants to call a default constructor, when I give the arguments ii and DONT want to call the default.
#include <iostream>
using namespace std;
class A {
int i;
public:
A(int ii) { i = ii; cout << "Constructor for A\n"; }
~A() { cout << "Destructor for A\n"; }
void f() const{}
};
class B {
int i;
public:
B(int ii) { i = ii; cout << "Constructor for B\n"; }
~B() { cout << "Destructor for B\n"; }
void f() const{}
};
class C:public B {
A a;
public:
C() { cout << "Constructor for C\n"; }
~C() { cout << "Destructor for C\n"; }
void f() const {
a.f();
B::f();
}
};
class D:public B {
C c;
public:
D(int ii) { B(ii); cout << "Constructor for D\n"; }
~D() { cout << "Destructor for D\n"; }
};
int main() {
D d(47);
}

Answer 1

Your parent constructor should be called in the initializer list:
class D:public B {
C c;
public:
D(int ii) : B(ii)/* <- */ { cout << "Constructor for D\n"; }
~D() { cout << "Destructor for D\n"; }
};
Note the /* <- */ comment. That needs to be changed.
What you are doing right now is to create an instance of B() in you class D constructor, which is not being used:
D(int ii) { B(ii); /* <- useless*/ }

Answer 2

D(int ii) { B(ii); cout << "Constructor for D\n"; }
Calls the default constructor of B. The B(ii) creates an temporary object of B which gets destructed as soon as constructor of D returns, In short it does not call the constructor for Base class of object which is being constructed.
Solution:
To be able to call a particular constructor of your Base class you should use Member Initializer list.
D(int ii) : B(ii)
{
}

Answer 3

This code:
class C:public B
{
C() { cout << "Constructor for C\n"; }
};
attempts to call B's default constructor.
You might want:
class C:public B
{
C() : B(0) { cout << "Constructor for C\n"; }
};
but that depends on your logic.
The following is also wrong:
D(int ii) { B(ii); cout << "Constructor for D\n"; }
it should be
D(int ii) : B(ii) { cout << "Constructor for D\n"; }
Calling the base class constructor in the body of the child class constructor merely creates a temporary object which doesn't do anything. To get the behavior you expect, you must call the constructor in the initializer list.

Answer 4

You're creating a D, which is derived from B -- but D's ctor doesn't pass a parameter to B's constructor, which would require that B have a default ctor.
To fix this, you typically need to write D to provide a parameter to B's ctor:
class D : public B {
C C;
public:
D(int ii) : B(ii) { cout << "ctor for D\n"; }
};

Answer 5

You need to realize that base and member subobjects are constructed by the time you enter the body of your constructor! That is, if you have a base or a member which doesn't have a default you need to pass its argument in the member initializer list:
D(int ii): B(ii) { std::cout << "constructor for D\n"; }
The object you constructed in your body of the D constructor is just a temporary object which doesn't really serve any purpose in your case (temporary object may be useful in some cases, though).