To format the answer as HTML content within a div, you can use the following code:
“`html
A missing vtable usually means the first non-inline virtual member function has no definition.
Explanation:
- A virtual member function in C++ is a function that can be overriden by derived classes.
- When a class contains a virtual function, it typically has what’s called a vtable (virtual function table).
- The vtable is a data structure that holds pointers to the virtual functions of the class.
- However, if the first non-inline virtual member function of a class has no definition (i.e., no implementation), the compiler will not generate a vtable for that class.
Example:
#include <iostream>
using namespace std;
class Base {
public:
virtual void foo() = 0;
};
class Derived : public Base {
virtual void foo() {
cout << "Derived foo()" << endl;
}
};
int main() {
Base* b = new Derived();
b->foo();
return 0;
}
“`
This code will display the answer within a div element, including the explanation and an example C++ code snippet.