All Questions
Tagged with polymorphism virtual
234
questions
0
votes
1
answer
63
views
C++ virtual template member function [duplicate]
#include <iostream>
class Data_X {
public:
Data_X(int x): x(x) {}
int getData() {
return x;
}
private:
int x;
};
class parent {
public:
template <typename T>
T* ...
- 85
-1
votes
1
answer
248
views
C++ polymorphism not working with ESP-IDF
I have an abstract class
namespace AComp
{
class A
{
public:
virtual void func() = 0;
virtual ~A();
};
A::~A() { }
}
I also have an abstract sub-class which does not ...
- 172
7
votes
1
answer
186
views
Is placement new of Derived type within a vector / array of Base type legal
Is placement new of derived object within a vector / array defined to be base object legal
#include <iostream>
#include <memory>
#include <vector>
struct A
{
virtual ~A()
{
...
2
votes
3
answers
121
views
Virtual C++ method with no polymorphism
Suppose you have this simple class hierarchy:
struct base {
virtual void f () const = 0;
};
struct derived : public base {
virtual void f () const final
{
...
}
};
There is ...
- 21
0
votes
1
answer
29
views
Unable to make abstract member with a pointer to itself in the parameter
I need help. How can I get something like this to work?
// main.cpp
class A {
public:
virtual void foo(A* a) = 0;
};
class B : public A {
public:
void foo(B* b);
};
void B::foo(B* b) {
/...
2
votes
2
answers
95
views
Are there any advantages to pure virtual members (except the human error that they might prevent)?
I have a stack of classes with pure virtual members, it'll be populated by derived non-abstract classes. I'm getting the error:
Error C2259 'ABC': cannot instantiate abstract class TEMP c:\...
- 35
-1
votes
1
answer
64
views
function call inside polymorphic call. virtual function call
The following is calling Derived::fn2() from Derived::fn1(), where as fn2() is not virtual so it should call Base class's function. Could anyone explain why?
#include <iostream>
using namespace ...
2
votes
4
answers
693
views
What are the use cases for a base class pointer pointing to a derived class object
I'm a new to OOP and trying to learn C++ and I came cross polymorphism and using the virtual keyword.
I just don't understand why we might need to do that.
I've checked this site for similar questions ...
0
votes
2
answers
72
views
an array of non-coherent types, that have something in common (array of concepts)
I think the use case is frequent, when you have multiple templated classes that have an element (variable or fcn) in common, and you want to call the fcn for all of them in a loop-like way.
Clearly, ...
1
vote
0
answers
39
views
Can you have a virtual function of type Parent class and then override it as Child type (c++)? [duplicate]
Given the following structure of a Parent class and 2 childs.
class Data{
protected:
int data;
};
class TreeData: public Data{
// something
};
class PlantData: public Data{
// something
};
...
user17477528
-1
votes
1
answer
122
views
Polymorphism without implementing all virtual methods
Is NOT implementing a virtual method in all derived classes considered a bad programming practice when using polymorphism?
Let's say I have an Enemy class and a couple of derived classes. All of the ...
- 25
3
votes
1
answer
113
views
Is overriding destructor for automatic object well defined?
I had a situation where I wanted to import a call after another call from the calling function. I decided to override a virtual destructor for the purpose:
#include <iostream>
struct type {
...
- 3,674
0
votes
0
answers
139
views
Alternative approach to virtual template method
i am trying to solve this for some time and i hope to find some help here. I have a base class and inside the base class i need a template method. But this method can not be virtual (which i know) so ...
- 165
0
votes
1
answer
84
views
About virtual functions
I have the following code snippet:
#include <iostream>
#include <typeinfo>
using namespace std;
class A{
public:
int x;
A(int i = 0): x(i) {}
A minus(){
return 1 - x;
...
user16188058
0
votes
1
answer
75
views
Does a virtual in a method of a c++ class trickle down to it's children [duplicate]
Why will the method of the subclass on the bottom of the tree be executed in this example?
I thought that the virtual only means that if I execute the method via a pointer of the class, but that one ...
- 56