i have 2 classes, one class which inherits it's parameters from an abstract class:
class Child : public Base {
public:
Child(string s, int i, ) : Base(s, i){};
... // methods
};
and another which has two overloaded constructors, one uses normal parameters and another, gets the same parameters but from the first class' already existing object:
header file:
class Other {
private:
string s;
int i;
Child o;
public:
Other(string str, int num);
Other(Child ob);
};
cpp file:
Other :: Other(string str, int num) : s(str), i(num) {/* this is where the error happens*/};
Other :: Other(Child ob) : o(ob) {
};
but when i try to compile i get an error at the marked place "C2512 'Other': no appropriate default constructor available"
What could be the problem? i really need to to pass that object into the constructor
Here:
Other :: Other(string str, int num) : s(str), i(num)
you need to construct the child object:
Other :: Other(string str, int num) : s(str), i(num), o(str, num ) {}
You don't have Child::Child()
. Since you don't list o
in the initializer list in the error line, Child::Child()
is getting called. This empty constructor is automatically added when there is no other constructor. Given that you have Child::Child(string s, int i)
, compiler will not auto create Child::Child()
.
This occurs because Other
has a Child
member, but you haven't given Child
a default constructor (a constructor that takes no arguments). Since Child
doesn't have a default constructor, the compiler has no idea how to create an instance of Child
, so you have to tell it.
Other :: Other(string str, int num) : s(str), i(num), o(some_value_of_type_Child) {};
I'm just guessing here but I suspect the Other
constructor taking a string and an integer is supposed to use those arguments to construct the Child
object.
Then you should do something like this instead:
Other:: Other(string str, int num) : o(str, num) {}
And of course remove the s
and i
member variables from the Other
class.
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