Questions tagged [casting]

Casting is a process where an object type is explicitly converted into another type if the conversion is allowed. This process might lead to a change in value.

Some algorithms have significant performance differences for different data-types, for example, calculating the N-dimensional median is much is much faster for integers than float type data. Therefore, the use of casting can be important for code performance.

19752 questions

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Cast int to char array in C

Is is possible to convert int to "string" in C just using casting? Without any functions like atoi() or sprintf()? What I want would be like this: int main(int argc, char *argv[]) { int i = 500; char c[4]; c = (char)i; i = 0; i…

asked May 07 '13 at 22:36

Bodosko

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3 answers

SQL Select All and change the format of one column

I was wondering. If I have a table with 20(or more) column names in and I want to select All of them, but one column of those 20 columns is a date column and you would like to change the format of that column, how would you do that? This obviously…

sql select casting

asked Apr 15 '13 at 12:28

Ruan

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Does this pointer casting break strict aliasing rule?

This is the fast inverse square root implementation from Quake III Arena: float Q_rsqrt( float number ) { long i; float x2, y; const float threehalfs = 1.5F; x2 = number * 0.5F; y = number; i = * (…

c pointers casting c99 strict-aliasing

asked Apr 04 '13 at 18:29

Vilhelm Gray

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C++ casting static two-dimensional double array to double**

I have such matrix in my program: double m[3][4] = { {2, 4, 5, 7}, {4, 5, 1, 12}, {9, 12, 13, -4} }; And I'd like to cast it to double** type. I've already tried simple double** a = (double**)m;, but it doesn't work…

c++ pointers casting double

asked Apr 02 '13 at 14:13

Greg Witczak

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void* is literally float, how to cast?

So I'm using this C library in my C++ app, and one of the functions returns a void*. Now I'm not the sharpest with pure C, but have heard that a void* can be cast to pretty much any other *-type. I also know that I expect a float at the end…

c++ c casting void void-pointers

asked Mar 09 '13 at 17:21

xNidhogg

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3 answers

Where does the C++ standard describe the casting of pointers to primitives?

In the excellent blog post What Every Programmer Should Know About Undefined Behavior, the section "Violating Type Rules" says: It is undefined behavior to cast an int* to a float* and dereference it (accessing the "int" as if it were a "float"). C…

c++ casting language-lawyer

asked Feb 06 '13 at 13:59

Martin C. Martin

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How to dynamically cast an object of type string to an object of type T

I have this XML document False in my code and I'm trying to build an array of arguments containing the node. object test = (object)…

c# generics casting

asked Sep 23 '09 at 13:03

LolaRun

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5 answers

const_cast vs reinterpret_cast

Referring the SO C++ FAQ When should static_cast, dynamic_cast and reinterpret_cast be used?. const_cast is used to remove or add const to a variable and its the only reliable, defined and legal way to remove the constness. reinterpret_cast is used…

c++ casting constants reinterpret-cast

asked Jan 11 '13 at 06:01

Abhijit

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Most efficient way to convert java.lang.Long to primitive int

I have a weird scenario where I need to convert several million java.lang.Longs into primitive int types. I need to do this several times a day, every single day. Normally, I wouldn't worry about this kind of simple casting, but since it's happening…

java performance casting

asked Jan 05 '13 at 15:39

IAmYourFaja

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2 answers

Is reinterpret_cast bad when dealing with low-level byte manipulation?

I'm writing a websocket server and I have to deal with masked data that I need to unmask. The mask is unsigned char[4], and the data is a unsigned char* buffer as well. I don't want to XOR byte by byte, I'd much rather XOR 4-bytes at a…

c++ casting c++11 reinterpret-cast

asked Dec 30 '12 at 23:17

matthewaveryusa

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3 answers

primitive-boolean To String concatenation/conversion

how does this work? I can't seem to find an answer. boolean bool=true; System.out.println("the value of bool is : " + true); //or System.out.println("the value of bool is : " + bool); What are the things that are going on behind the scene? how…

java string casting boolean string-concatenation

asked Dec 15 '12 at 18:22

Vinay W

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Casting stream to filestream

Possible Duplicate: Convert a Stream to a FileStream in C# My question is regarding the cast of stream to FileStream ... Basically I need to do that to get the name of the file, because if I have just an object Stream it doesn't have the Name…

c# casting stream filestream

asked Nov 30 '12 at 07:28

Alnedru

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How do I cast an int value to a generic type parameter that is equivalent such as char?

I'm new to generics and I'm having some trouble implementing a small self practice code. I'm creating a linked list. I want it to store char or int values. So I decided to make the implementation generic: public class Node where T : struct,…

c# generics casting linked-list type-conversion

asked Nov 23 '12 at 20:17

user1730118

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6 answers

Why is this cast from interface to class failing?

private Vector2 ResolveCollision(ICollidable moving, ICollidable stationary) { if (moving.Bounds.Intersects(stationary.Bounds)) { if (moving is Player) { (Player)moving.Color = Color.Red; } } //…

c# casting

asked Nov 09 '12 at 14:11

ssb

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How to cast Generic Lists dynamically in C#?

I'm trying to cast List