C# :: Static Method Inside Non-static Class

Aug 22, 2014

Have following code:

class Program
{
static void Main(string[] args)
{

[Code]....

My question according to what i just wrote:

1. Is that mean that Do() is only available for use by Dog itself because Dog is 'oryginal' Dog, and if i create new dogs - instances of oryginal Dog (dog1, dog2 ...) they cant access because Do is only available fo 'oryginal' one? Is that correct thinking?

2. If i would want to have something common (e.g value) for all dogs is that good way to create static field/method for Dog instead of non-static once then all instances of Dog would access Dog static member to get/change it? Just stupid example: static method GetAmountOfLegs() which return 4 Then all instances can take/call that value from Dog. Is that correct thinking?

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C++ :: Accessing Non-static Members Inside Static Member Functions

Sep 11, 2013

What are the workarounds for accessing the non-static member variables of some class(Say A) inside static member functions of another class(Say B)? I am coding in c++. Class A is derived with public properties of class B. Any pointers?

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C Sharp :: How To Use Static Method And Datatype In A Class

Apr 3, 2013

How to use static in a class, function and variable.

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C++ :: Do Static Functions Have Access To Non Static Data Members Of A Class

Apr 17, 2013

From my book:

"A static function might have this prototype:

static void Afunction(int n);

A static function can be called in relation to a particular object by a statement such as the following:

aBox.Afunction(10);

The function has no access to the non-static members of aBox. The same function could also be called without reference to an object. In this case, the statement would be:

CBox::Afunction(10);

where CBox is the class name. Using the class name and the scope resolution operator tells the compiler to which class Afunction() belongs."

Why exactly cant Afunction access non-static members?

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C++ :: How To Access Class Member And Methods From Static Method (signal Handler)

Dec 4, 2014

I am writing my program on C++ language. I have one promblem. I need to set signal handler for my process. As the signal is related with the process on system level I have faced the problem.

My program consists several classes. They are connected together. But it doesn't metter in this case. The problem is that I need to access to member and methods of the class from my signal handler. For instance , I have class named Foo at it has some members and methods.

So from my handler I need to call its function and change members.

I understand that compiler should know that this class instances will exist during all program execution.

I have tried to set static member class Foo instance in another class , but this didn't solve the problem.

What is correct approach to do this. How to correctly implement signal handling in such case.

Here is example of my code

Code:
class MyContainer{
private:
std::vector<Foo> container;
public:
int removeFromContainer(Foo* aFoo) {

[Code] .....

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C++ :: Make Class Created Static Inside Another Class?

Dec 17, 2013

it seems everytime i use statics in a class i come across with a porblem.

this time i wanted to make a class i created static inside another class.

MainVariables.h file
static fge::window mWinMain;

if someone ever wants to reach it
MainVariables.cpp file

fge::window MainVariables::mWinMain;
...
...
fge::window MainVariables::GetWinMain()
{
return mWinMain;
}

but when i created some other MainVariables classes at other places instead of them reaching to the same window two window is being created.

yes i know maybe there are better methods but currently i m working on polymorphism and i need some static members.

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C++ :: Undefined Reference To (method Name) When Accessing Method In Static Library

Jan 17, 2013

I've been trying for more than one month to access a method found in a library called libcocosnas_static.a. I'm using Cocos2d-X version 2.0.4. The library has been used many times by my company to make games using cocos2d-1.0.1-x-0.12.0 without any problem.

This is what I've done:
1- I added the include paths of the library to both eclipse and Android.mk
2- Included the .h file using #include "NASPlatformUtil.h"
3- Added the libcocosnas_static.a file to the proj.androidobjlocalarmeabi folder
4- Added "LOCAL_WHOLE_STATIC_LIBRARIES += cocosnas_static" to the Android.mk file
5- Called the function using: NASPlatformUtil:: openUrl("http://xxx.xxx.com/");

I can right click on the function, click Open Declaration and get it without any problem, but the compiler keeps on giving me that dreaded error...

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C Sharp :: Why Use Static Method In C#

Feb 17, 2013

what is static method?

why we can use static method inc#?

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C++ :: Implementing Static Templated Method In Cpp File

Apr 16, 2012

I declared a member method to a class in its header file and implemented it in the cpp file. When I build and run the project in XCode, everything works fine. When I try to do it with a makefile, I get undefined symbols linker errors.

parser.h

Code:
#ifndef ENGINE_SCRIPT_PARSER_H
#define ENGINE_SCRIPT_PARSER_H
#include <string>
#include "variable.h"
namespace ninja_game_engine {

[Code] ....

The exact makefile looks like this:

Code:
test:
g++
Code/Engine/Modules/Timer/timer.cpp
Code/Engine/Modules/list.cpp

[Code] ....

I'm pretty sure that there is a weird namespace gotcha that I'm unaware of that LLVM (default OSX compiler) is compensating for that g++ isn't. Or maybe something weird with the optimization? I want the tests running at that level to make sure everything that is volatile is declared as such.

Rest of the code located here: [URL] ....

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C++ :: Using Static Method To Check Arguments Before Calling Constructor?

Mar 1, 2013

I would like to avoid throwing things in constructors as much as possible.

Is this good design to have a static class method that checks arguments the caller will give to the constructor. The documentation of the class will say, thou shall call this method to validate thine arguments before calling the constructor, or else segfault may befall thoust.

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C# :: Breaking Dependency In Static Method For Unit Test?

Feb 6, 2014

I have function that returns historical data. I can access it, using file name. If I use file name, it reads that file and saves it to dictionary, so that in the future, if historical data is required for the same file, it does not read it again (it's lazy loading). If no file is supplied to the function, it tries to read file which is given in app settings.

However, for unit testing, I do not want to read any file. Instead, I want it to use small sample of hardcoded historical data. In order to do that, I think, I need to introduce interface to it. Then I can use some IoC to choose between different implementation for unit testing purpose and ordinary launch of application.

Function to get history is given as follows:

public static class Auxiliary
{
private static Dictionary<string, MyData> _myData;
public static MyData GetData(string fileName = null)
{
// ...
}
}

I have created default Unit Test project with Visual Studio so, as far as I know, by default it uses MSTest as test runner and MSUnit as unit testing framework but it does not have any IoC container so I should manage NuGet packages for solution and install Unity.

As far as I know, MSUnit (aka Moles) can unit test static methods (it's unconstrained isolation framework, like Typemock Isolator, unlike NUnit) but still many people suggest not to use any static methods for unit testing.

Should I use shim or stub [URL] Stubs should be used for faking external dependencies and here it is not external library, but my own code.

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C++ :: Static Variable Inside A Member Function

Jul 20, 2013

Say you had:

class Foo{
public:
//...
void funky();

[Code] .....

Would each instance of Foo create a new counter variable, or would it remain the same for all of them, i.e. baz.funky() would always use the same counter variable? What if the class was a template?

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C++ :: Static Type Dispatch With Structs Inside Classes?

Oct 15, 2013

I wanted to ask if it is somehow possible to do:

Code:
class RaspberryPi: public Singleton<RaspberryPi> {
private:
static const DeviceInfo GPS;
template<typename Register_t>
auto ReadGPS(Register_t& Register) -> void

[Code] ....

There are two limitations I am facing:

First, it seems that anything that is part of a struct cannot be a compile-time expression. It's a nice way to group information, so it would be nice to have.

Secondly, it seems that all compile-time expressions cannot be inside a class (at least according to VC++), which means I have to move them to global level, but while it can be done, I don't really want to do it, because it's a platform detail.

In this case, static type dispatch would be nice to have because I have a function

Code:
template<typename Register_t>
auto ReadBus(Platforms::DeviceInfo Device, Register_t& Register) -> void {
switch (Device.Bus)

[Code] .....

There are two types of registers. With runtime dispatch, I get disgusting errors such as "could not deduce template arguments, blah blah" if some object doesn't have the required interface (i.e., don't have overloads for both register types). So the workaround would be to add two overloads and use something like asserts to stop invalid code from running, but it would be so nice to only allow correct code to compile and not get scary error messages.

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C/C++ :: Difference Between Declaring Static Variable Inside And Outside Of Main

Apr 6, 2012

I want to know

prog1.c
#include<stdio.c>
static int c=6;
int main() {
/*code*/
}

prog2.c
#include<stdio.h>
int main(){
static int c=10;
}

what would be the difference between these two program in the fuctioning of static keyword ?

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C++ :: Undefined Reference Error When Accessing Static Variable Inside Member Function

Feb 10, 2013

I am modifying a set of static variables inside of the class's member function. The static variables are private. An example of what I'm doing is as below,

utilities.h
-----------
class utilities {
private:
static int num_nodes;

public:
void parse_details(char* );

[Code] ....

I get a compilation error in the function void utilities::parse_details(char* filename)

which says: undefined reference to `utilities::num_nodes'

compiler: g++

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C++ :: How To Initialize Static Member Of Class With Template And Type Of Nested Class

Oct 7, 2014

How to initialize a static member of a class with template, which type is related to a nested class?

This code works (without nested class):

#include<iostream>
using namespace std;
struct B{
B(){cout<<"here"<<endl;}
};
template<typename Z>

[Code] ,....

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C++ :: Difference Between Static Local Variable And Static Global Variable?

Aug 5, 2013

Here is the code,

Code:
class A {
};
A& CreateObject() {
static A a;
return a;
} static A aa;
int main() {
return 0;
}

So is there any difference between a defined in CreateObject and aa?

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C++ :: In Class Static Map Initialization

Nov 17, 2014

I have a class containing a map member that I want to initialize at declaration time. I know I can do it in the cpp file but I'm having a problem with the order of initialization (static initialization order fiasco).

My questions are:

Is it possible that the scenario in which, the Test's constructor's implementation and the map initialization instruction are in the same cpp file and constructor is called when the map is not initialized yet, could happen?

Is it possible to initialize the map in class like I did? I get these errors:

in-class initialization of static data member 'std::map<std::basic_string<char>, Test*> Test::a' of incomplete type
temporary of non-literal type 'std::map<std::basic_string<char>, Test*>' in a constant expression

If yes, does this initialization resolve the static initialization order fiasco?

class Test {
public:
static std::map<std::string, Test*> a = {};//this is an error
Test(std::string ID) {

[Code] ....

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C++ :: Static Object Of Same Class

Jul 27, 2013

What is the purpose of having static object of the same class.

E.g.

class someObj{
public:
static someObj obj;
};

how the compiler treats this object

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C# :: Static Class For Logging?

Mar 14, 2014

I am developing logging class and it loos like below now, my question here is I would like to avoid situation to call this class methods multiple times in same time - as I've read when I have static class or even static method (not exactly whole class) it can be call only once in time. Is this true and whether my class would pass the concept to avoid multi accessing - lets say in case of multithreading case - if one task would try to call statuc method when there is already some other trad using it.

public static class Log {
public static string EngineName { get; set; }
private static List<String> logdata = new List<string>();
public static void LogMessage(string msg, ELogflag flag, string title = "") {
StringBuilder sb = new StringBuilder();

[code]....

And my new Enum:

enum ELogflag {
LOG,
ENGINE,
CRITICAL,
CUSTOM
}

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C++ :: Static Data Of A Class

Oct 14, 2012

I am studying the use of static data into classes and the code below is returning an error ...

#include <iostream>
using namespace std;
class REC {
private:
static int n; //Dado que sera unico na classe e alterado por todos os objetos

[Code] .....

The error:
main.obj:-1: error: LNK2001: unresolved external symbol "private: static int REC::n" (?n@REC@@0HA)
Note: I'm using QT Creator

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C++ :: Static Pointer To Class That Is Used Globally

Oct 10, 2013

If I need a static pointer to a class that is used globally(multiple files), and I only want to allocate memory once.

One way is to create a function that returns a static pointer of type class and call it where ever you need this pointer. My question is there another way to do this like with a header file and include the header file where you need to use the object of type class.

static class* function
{
static class c;
if (c == NULL)
{
c = new class;
}
return c
}

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C++ :: Abstract Static Class And Performance

Nov 11, 2014

I have the following code:

class Element {
public:
..
virtual unsigned NumberOfNodes() = 0;

[Code] ....

Is it possible to implement this better? All the element stuff can be static, but this is not possible with the abstract class. I want to have Mesh independent of a specific element. With the code above, if I have multiple meshes I have one instance of an element, e.g., Triangle for each mesh. Although they are all exactly the same.

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C++ :: Static Const Class Instances?

Jun 17, 2012

i have this rather large class, which (in a way) somehow resembles a custom dialog control). This control is supposed to display data, which it does just fine. To do so, it maintains a

byte settings[10];

array, which holds information on how to display the data.

There are multiple ways to represent this custom set of data.In order to remain flexible in representing it, i thought of implementing some sort of DisplayProvider, which can be registered to the base class and provides that settings byte array.

Preferably, i would now have a set of static const instances of this provider.Using a struct would work nicely here:

PHP Code:

struct DisplayProvider
{
int settings[10];
}
static const DisplayProvider prov1 = {1,2,3,4,5,6,7,8,9,0}; 

The problem: The DisplayProvider would have to do some pre-processing, before handing over control to the base class, which then does the main work.I would end up with something like this:

PHP Code:

class DispalyProvider
{
baseclass* owner;
 int settings[10];
void PreProcessing(...);//ends up calling the owner.Processing(...) function
}; 

The main thing here is, that i dont really see a way to create a stock of default "static const DisplayProvder = {...}"s, as i could when using a struct.

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C++ :: Static Constant Datatype For Fraction Class

Aug 4, 2013

My Fraction.h class looks like :

class Fraction {
int num;
unsigned int den;
public:
Fraction(int = 1,int =1);
//Constants of Datatype

[Code] ....

The implementation Fraction.cpp is as follows :

#include "Fraction.h"
Fraction::Fraction(int n, int d):num(n),den(d){
cout << This is double param constructor <<endl;
}

And the application main.cpp is

int main(){
Fraction f1(3,9);
f1 = Fraction::sc_fUnity; // how to implement this ?
}

How can I write the Fraction.cpp for the constant static member ?

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C++ :: Function Pointer To Non-static Class Member

Aug 19, 2014

I have the following problem: I am using NLOpt for optimization. The API provides functions to set the objective. This is done as follows:

double objective(const vector<double> &x, vector<double> &grad, void *data)
{
return x[1]*x[0];
}
int main(){
nlopt::opt opti(nlopt::LD_MMA,2);
opti.set_min_objective(objective,NULL);
vector<double> x(2);

[Code]....

Now I want to make the function objective a member of a class:

class Foo {
public:
double objective(...){..}
};

How can I give this method to opti.optimize? If I make objective static I can use

opti.optimize(Foo::objective,NULL);

but I do not want to have a static member. Is it possible to create an object of type Foo and give it to opti.optimize?

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