Downcasting permits an object of a superclass type to be treated as an object of any subclass type.
Questions tagged [downcast]
589 questions
2
votes
2 answers
Downcasting instance from external Jar
//Class defined in external jar
class A{
many methods...
public getId() {};
}
//I want to extends this class and overwrite single method
class MyA extends A{
private int myId;
public getId() {return myId};
}
void main ()
{
A a =…
user3369398
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2
votes
2 answers
casting base class to derived class via reflection
Hi I have to construct an object from an object. Since the base class has more than 50 fields i dont want to do things like
//obj1 is an instance of BaseClass
DerivedClass obj2 = new…
jit
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votes
3 answers
How can I correctly downcast the pointer from void* to TMemo* in C++Builder2009?
I am writing multi-thread socket chat in C++Builder 2009.
It is almost complete in accordance with what I need to do but I have a little problem.
I need to pass the TMemo* pointer into CreateThread WinAPI function which upcasts it to void*.
I tryed…
chester89
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2
votes
3 answers
Swift View Controller Downcasting
I thought the following would populate my home variable with my HomeViewController
var home = self.parentViewController!.parentViewController! as HomeViewController;
Instead I get the following compile error 'Use of undeclared type…
Ben_hawk
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2
votes
1 answer
Downcast from AnyObject?
I am a bit puzzled as to what is going on with the code below. I was under the impression that children would be an optional based on node.children (which is of type [AnyObject]) being of type [SKNode] What I am seeing is that children is never nil,…
fuzzygoat
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votes
3 answers
How to downcast array of object type into an normal array?
I planned to convert an ArrayList into an normal array. After that i tried to downcast that object type into a normal array.But its showing that "Cannot convert from Object to int" at line 17.
package coll;
import java.util.ArrayList;
public class…
karthick raja
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2
votes
4 answers
Polymorphic Downcasting in c#?
I'm trying to make food for my IAnimals using a FoodFactory and have a large List of Dogs and Foxs etc. Ideally, I would pass in an IAnimal and the FoodFactory would return the right food but I am not sure how to do this.
interface IAnimal…
Big AL
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2
votes
1 answer
Downcasting Multidimensional Arrays Swift
I am trying to downcast a multidimensional array property which is required by a protocol in a subclass of the protocol conforming class. However currently the compiler is giving me a an error when I do so. The error is: 'DataClass' is not identical…
Jad
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votes
1 answer
Swift: Downcasting to Generic Type in Function Failing
I have a generic function that takes a value of any object and an in-out parameter with type T. I want to set the in-out parameter to the value of the any object by downcasting the value to type T.
func genericFunction(value:AnyObject, inout…
Trung
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2
votes
3 answers
How can I avoid Java downcasts?
I currently am working on a project where I have 3 user classes, lets say UserA, UserB, UserC, that inherit from a abstract User class.
The program is supposed to emulate a system wish requires users to login and logout.
The instances of those users…
user2009400
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2
votes
2 answers
What happens internally when we do downcasting?
I was trying to understand down-casting... Here is what I have tried...
class Shape
{
public:
Shape() {}
virtual ~Shape() {}
virtual void draw(void) { cout << "Shape: Draw Method" << endl; }
};
class Circle : public Shape
{
public:
…
StackIT
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2
votes
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How to implement a generic interface between C++ and Java using SWIG and Downcasts?
I´m writing an application which is intended to run on different platforms.
My base library is written in C++ and I´d like to use SWIG for generating platform-specific code (Java/Android, C#/Windows, Objective C/iOS).
Here I´m using Message-Objects…
koch.trier
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2
votes
2 answers
How to Downcast to an Overloaded Method
I have a slight problem in my code here I think is interesting:
foreach(ISceneNode node in (root as IGroupNode))
{
PreVisit(node);
if (notFound == false)
{
return node;
…
Musicode
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2
votes
3 answers
How haskell 'downcast' a type interface?
In oop, such as java, we can only downcast a super class into subclass when the type actually is the subclass.
But In haskell, we can simply 'downcast' a type class into any instances of that type class. Such as fromInteger which return a Num. From…
code4j
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votes
2 answers
Is it really downcasting not possible? It is working fine for me
I know there are already some questions posted related to this same topic, but I have seen different answers so I am quite confused on which answer is correct.
On the below link, people mentioned that downcasting is not possible
Convert/Cast base…
Superman Coding
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