Downcasting permits an object of a superclass type to be treated as an object of any subclass type.
Questions tagged [downcast]
589 questions
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4 answers
Downcast from Generic without losing expressiveness
I've something along this lines:
public class Something
{
private IDictionary fCases;
public IDictionary Cases
{
get { return fCases; }
set { fCases = value; }
}
}
public sealed…
Joao
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why should i downcast the context as an instance of the interface?
I just started to learn the fragment API on Android.
I want just to send a message back to my containing activity(I did it). Now I want to clear a misunderstanding about downcasting.
Here is my fragment:
import android.content.Context;
import…
Hamza Belmellouki
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C# Down casting Parent Object to Subclasses
I receive a list of Parent Objects(Devices) and would like to convert each Device Object into a subclass Object. The layout would looks something along the lines of:
public class Device
{
public string FimrwareVersion { get; set; }
public…
John Ucci
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How to downcast an array in Java?
I currently have a Tile class that extends a Node class, and want to downcast an array of Nodes to an array of Tiles like so:
class Node {
Node[] neighbours;
private final T value;
}
class Tile extends Node {
public Tile(Point value) {
…
Zac Sanchez
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upcasting and downcasting in C++
I was trying the idea of casting in C++ using Visual Studio C++ 2010 Express and the use of dynamic_cast.
But somehow, when I run it, an cat object can actually perform dog behaviour.
Seem like Dog d = (Dog)aa; got the compiler confused. Any…
aDeveloper
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1 answer
Rescaling and downcasting a float safely in C++
I am trying to bin a float number R and I want to obtain its weight wt in an unsigned 8 bit integer format:
float R;
float edgeVal = rintf(R); // round to the nearest edge
float dR = R - edgeVal + 0.5f; // distance to the edge with a half-pixel…
Airidas Korolkovas
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down casting for type classes in Scala
I have
trait OptionTransaction {
def data: Data
}
BuyOptionTransaction extends OptionTransaction
SellOptionTransaction extends OptionTransaction
I use these with a Formatter type class to create string representations of various…
Adrian
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Should downcasting be avoided while using a class hierarchy in C++?
Let's say I'm writing an application which works with projects, and exposes different functionality depending on the type of the project. I have a hierarchy of classes for the different types of projects:
class AbstractProject
{
};
class ProjectA :…
neuviemeporte
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Overload a C++ reference cast (downcasting inheritance)
Is is possible to overload a reference cast in C++?
I've got code I can't touch in the format:
void someMethod(Parent& parentReference, ...){
...
Child& child = static_cast(parentReference);
(The class Child inherits directly and…
fatman
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Warning when downcasting in Rcpp?
I have an Rcpp function that should take an IntegerVector as input (as toInt). I want to use it on vector of integers, but also on vector of doubles that are just integers (e.g. 1:4 is of type integer but 1:4 + 1 is of type double).
Yet, when this…
F. Privé
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Adding Parcelable interface to a class from external library
I'm using an external library for 3rd party map retrieving in Android.
There's a class that I want to pass through Intent, so I want to make it implement Parcelable.
But the class is from the external library.
What's the best practice to do in…
viz
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Detect Object type then cast it accordingly?
My method takes as input an Object. How do i determine it's type, then cast it accordingly?
So for example: binarySearch( Object o );
Inside the binarySearch method, i need a way to determine the type (or class) of Object o. Then i need to cast it…
trusktr
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What is better to use for downcasting boost::polymorphic_pointer_downcast or boost::dynamic_pointer_cast
I'm going to use downcasting in my project in order to cast one boost::shared_ptr<> to another one in class hierarchy. That is my test code where I am using boost/polymorphic_pointer_cast and boost::dynamic_pointer_cast both variant work. But I…
Space Rabbit
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C++11: Avoid downcasting when setting member variables for derived class
Let's say I want to build a Car which has components like Motor, Tire, etc. which are all derived from a "component" base class. Each component has its own states (i.e. motor has RPM, tire has pressure, and so on) as a subclass. A Car class stores…
DayAndNight
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F# Downcasting elements of DataTable
I'm trying to return data from a stored proc on SQL Server 2008 R2. (The stored proc didn't play nicely with Microsoft.FSharp.Data.TypeProviders and I wasted most of the morning going down this seemingly futile path.)
So I get a sequence of tables…
Talmage
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