boxing Questions
9
Solved
Given a generic parameter TEnum which always will be an enum type, is there any way to cast from TEnum to int without boxing/unboxing?
See this example code. This will box/unbox the value unnecess...
3
struct Point
{
public int x;
public int y;
}
void Main()
{
Point p;
p.x = 1;
p.y = 1;
Object o = p;
((Point) o).x = 4; // error
((Point) o).x = 5; // error
((Point) o).x = 6; // error
p =...
2
Let's say I'd like to ensure type safety in Java on primitive types. For the sake of an example, let us want to distinguish a Ratio from an AbsoluteValue, both are represented by a double.
Java to...
Termless asked 30/10, 2019 at 9:26
17
Solved
This may be a bit of an easy, headdesk sort of question, but my first attempt surprisingly completely failed to work. I wanted to take an array of primitive longs and turn it into a list, which I a...
Villein asked 16/4, 2009 at 0:19
2
Solved
The documentation of constant pattern matching with the is-operator (expr is constant) states:
The constant expression is evaluated as follows:
If expr and constant are integral types, the C# equ...
7
Solved
I was doing some reading regarding boxing/unboxing, and it turns out that if you do an ordinary String.Format() where you have a value type in your list of object[] arguments, it will cause a boxin...
3
Solved
I'm curious about how C# behaves when passing value/reference types into a method. I'd like to pass a boxed value type into the method "AddThree". The idea is to get in the caller function (Main) t...
Demurrer asked 21/11, 2015 at 14:25
4
Solved
Why a generic method which constrains T to class would have boxing instructions in the generates MSIL code?
I was quite surprised by this since surely since T is being constrained to a refer...
1
Solved
In the below code, the line System.out.println(sumInteger(bigs) == sumInteger(bigs)); displays as false. But when again we compare the another Integer wrapper classes System.out.println(bc ==...
4
Solved
I came across this and am curious as to why is it not possible to use the is operator to discern between bool and Nullable<bool>? Example;
void Main()
{
bool theBool = false;
Nullable<b...
2
Solved
I can think of two ways:
public static IntStream foo(List<Integer> list)
{
return list.stream().mapToInt(Integer::valueOf);
}
public static IntStream bar(List<Integer> list)
{
retur...
Emmer asked 8/7, 2014 at 14:5
5
Solved
I have the following code in Java :
class Boxing
{
public static void main(String args[])
{
short s = 10;
Integer iRef = s;
}
}
Why does it produce an error in compilation? If I explicitl...
Amorphism asked 23/11, 2015 at 9:59
4
Solved
Is there a standard method I can use in place of this custom method?
public static Byte[] box(byte[] byteArray) {
Byte[] box = new Byte[byteArray.length];
for (int i = 0; i < box.length; i++)...
2
Solved
I'm having trouble understanding how values of boxed traits come into existence. Consider the following code:
trait Fooer {
fn foo(&self);
}
impl Fooer for i32 {
fn foo(&self) { println!...
Pecker asked 12/9, 2018 at 6:45
3
Solved
I have the following Java 8 code (simplified for demonstration):
public Double fooBar(int a) {
return Double.valueOf(a);
}
Now IntelliJ IDEA tells me that I have unnecessary boxing in the retur...
Tree asked 21/2, 2017 at 8:9
3
Solved
My question is somewhat related to this one: How does a generic constraint prevent boxing of a value type with an implicitly implemented interface?, but different because it shouldn't need a constr...
Indulgent asked 27/4, 2011 at 23:57
1
Solved
I'm trying to define a function that will take a reference as a parameter, and call a generic method on the referenced object, passing in a concrete value. I need a way of requiring that the generi...
5
Solved
Boxing is when a value type is assigned to an object type. Is it the same when a reference type is assigned to an object?
When a type (which isn't object) is assigned, what happens? Is that boxin...
7
Solved
What is the difference between these two. I know Boxing is converting primitive values to reference. What is widening. Also what should be the sequence first boxing should be done or widening shoul...
3
Solved
Something just occurred to me earlier today that has got me scratching my head.
Any variable of type Nullable<T> can be assigned to null. For instance:
int? i = null;
At first I couldn't ...
1
Solved
This is a very specific and long question, but I'm not smart enough to figure it out by myself..
I was very intrigued by this YouTube-video from raywenderlich.com, which uses the "boxing" method t...
2
Solved
Previously a question was asked about creating an array of functions where the functions returned integers from a range. The final solution was to do a map/collect into a Vec<_>.
I have a s...
1
Solved
I looked around for this and could not find an answer. Say I have this code:
class Command<T> : ICommand<T>
{
public void Execute(T parameter)
{
var isNull = parameter == null...
5
Solved
Widening and Boxing Java primitives.
I know it is not possible to widen a wrapper class from one to another as they are not from the same inheritence tree. Why though is it not possible to widen ...
Itinerate asked 10/8, 2011 at 16:15
4
Solved
in the Android Java world, is there a straighforward (ideally one-call) way to convert an array of int to an ArrayList<Integer> and back? Calling toArray() on the ArrayList returns an array o...
Crandale asked 19/5, 2011 at 20:31
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