Re: static const int inside class [modified] - C / C++ / MFC Discussion Boards

vikramlinux17-Jul-06 22:15

17-Jul-06 22:15

hie Guys,

I have a class like

class ABC
{
public:
static const int var=10;
};

Here initialing the var with 10 is allowed inside class.

In early compilers(I have VC 6.0) it does not work but it works with VC7.0.

Rule says that only static integral constants are allowed to be initialized inside class.

May I know why this requirement came when we already have following facility as shown belows

class ABC
{
public:
static const int var;

};

const int ABC:: var =10;

Also My question is where is the compiler putting this code - static const int var=10 when it is inside a class?
It can not be in constructor or in memberwise Initialization list.So what is workaround? Why this is special case?

Vikram S

Re: static const int inside class

toxcct17-Jul-06 23:52

toxcct

17-Jul-06 23:52

vikrams wrote:
Also My question is where is the compiler putting this code

all the static initializations are done at the beginning of the application, whatever it is a class member or not.

TOXCCT >>> GEII power

[VisualCalc 3.0 updated ][Flags Beginner's Guide new! ]

Re: static const int inside class

vikramlinux17-Jul-06 23:55

vikramlinux

17-Jul-06 23:55

True. What about "static const" inside class?

Re: static const int inside class

toxcct17-Jul-06 23:59

toxcct

17-Jul-06 23:59

vikrams wrote:
What about "static const" inside class?

static const is static BTW, right ?

then same rule.

TOXCCT >>> GEII power

[VisualCalc 3.0 updated ][Flags Beginner's Guide new! ]

Re: static const int inside class

Maxwell Chen18-Jul-06 0:03

Maxwell Chen

18-Jul-06 0:03

static const members can be initialized inside class inline definition.

for example the below compiles:

class A
{
public:
	static const  int v = 3;
};

int main()
{
	A a;
	a.v;
	
	return 0;
}

Maxwell Chen

Re: static const int inside class

toxcct18-Jul-06 0:06

toxcct

18-Jul-06 0:06

then... isn't it what i was saying ?

even if you write the initialization there, the code is executed at the beginning of the program (because static members are initialized like that).

TOXCCT >>> GEII power

[VisualCalc 3.0 updated ][Flags Beginner's Guide new! ]

Re: static const int inside class

Rob Caldecott18-Jul-06 0:06

Rob Caldecott

18-Jul-06 0:06

Unless the static is within a method, in which case it is initialized the first time the method is called (potentially causing some thorny multi-threaded issues).

Re: static const int inside class [modified]

vikramlinux18-Jul-06 0:36

vikramlinux

18-Jul-06 0:36

Hey Guys,
What code u have provided is correct. I also mentioned same code in my question. I have 2 concerns

1) const static members can be directly init in class
so what is wrong with normal static members?

2) As normal const vars has to be init at the time of declaration in code(somewhat like references ). In my class I need to init my const var in memberwise init list.

so we have an issue where we have const needs whose init code needs to be inside class and static needs to be outside.

so the soln in compiler is put static const var outside let it be define there.
Here my question is why we can also put it inside class? what is req. forced to provide such facility? what is rational behind that?

-- modified at 6:46 Tuesday 18th July, 2006

Unregister same registering with 'regsvr32.exe' ?

Andy Rama17-Jul-06 20:46

Andy Rama

17-Jul-06 20:46

Hi to all,
How to Unregister a registered dll file, with or without coding ?
As we can Register a dll using 'regsvr32.exe', is there any option to unregister the register dll?

Thanks & Best Regards,
Aniket Salunkhe

Re: Unregister same registering with 'regsvr32.exe' ?

NiceNaidu17-Jul-06 20:50

NiceNaidu

17-Jul-06 20:50

To unregister regsvr32 /u C:\YourFile.OCX

Appu..
"If you judge people, you have no time to love them."

Re: Unregister same registering with 'regsvr32.exe' ?

Andy Rama17-Jul-06 21:03

Andy Rama

17-Jul-06 21:03

Thanks for help.

Re: Unregister same registering with 'regsvr32.exe' ? [modified]

AkiraOne17-Jul-06 20:52

AkiraOne

17-Jul-06 20:52

Start->Execute

type regsvr32 and then Enter.....

you can visualize a dialog options.

regsvr32 "file path" /u

Too many plans make the health badly!!

-- modified at 2:52 Tuesday 18th July, 2006

Re: Unregister same registering with 'regsvr32.exe' ?

Andy Rama17-Jul-06 21:04

Andy Rama

17-Jul-06 21:04

Thanks for help.

Re: Unregister same registering with 'regsvr32.exe' ?

Anilkumar K V17-Jul-06 23:37

Anilkumar K V

17-Jul-06 23:37

Ex for regster given , to un reg, get function pointer of "DLLUnReg...Svr"

HCRET lpfnDllRegisterServer = NULL;
DLLName = "YouDLLName.dll";
hDLL = LoadLibrary(DLLName);
if (hDLL != NULL)
{
lpfnDllRegisterServer = (HCRET)GetProcAddress(hDLL, "DllRegisterServer");
if(NULL == lpfnDllRegisterServer)
{
//ERR
}
else
{
if(FAILED((*lpfnDllRegisterServer)()))
{
ERR ("Tripio registration failed!");
}
else
{
//"Registering DLL Success"
}
}

FreeLibrary ( hDLL );
}
else
{
ERR("LoadLibrary failed");
}

Re: Unregister same registering with 'regsvr32.exe' ?

Andy Rama18-Jul-06 20:22

Andy Rama

18-Jul-06 20:22

Hi,
I tried ur code in VC6. But it is giving me Errors like,
: 'HCRET' : undeclared identifier

Thanks & Best Regards,
Aniket Salunkhe

Re: Unregister same registering with 'regsvr32.exe' ?

Anilkumar K V18-Jul-06 23:35

Anilkumar K V

18-Jul-06 23:35

Friend

HRECT is just a function pointer type def as

typedef HRESULT (CALLBACK *HCRET)(void);

Let me know worked or not to anilkumarkv@gmail.com

Re: Unregister same registering with 'regsvr32.exe' ?

ThatsAlok18-Jul-06 0:42

ThatsAlok

18-Jul-06 0:42

Aniket Salunkhe wrote:
As we can Register a dll using 'regsvr32.exe', is there any option to unregister the register dll?

you can dynamically load dll and call teh dllunregister routine

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
Support CRY- Child Relief and You

Re: Unregister same registering with 'regsvr32.exe' ?

Andy Rama18-Jul-06 20:27

Andy Rama

18-Jul-06 20:27

Hi,
I dont understand where this routine should be called.
If possible give me an example.

Thanks & Best Regards,
Aniket Salunkhe

Re: Unregister same registering with 'regsvr32.exe' ?

ThatsAlok18-Jul-06 22:23

ThatsAlok

18-Jul-06 22:23

Aniket Salunkhe wrote:

Hi,
I dont understand where this routine should be called.
If possible give me an example.

Let fatCom.dll is your DLL ....
then using LoadLibrary function load that dll in your Process memory space and using GetProcAddess Function get DllUnregister pointer and call that function!

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
Support CRY- Child Relief and You

Re: Unregister same registering with 'regsvr32.exe' ?

Andy Rama19-Jul-06 4:26

Andy Rama

19-Jul-06 4:26

ThatsAlok wrote:
then using LoadLibrary function load that dll in your Process memory space and using GetProcAddess Function get DllUnregister pointer and call that function!

I use code as follow,

HCRET lpfnDllRegisterServer = NULL;
	HINSTANCE  hDLL = LoadLibrary("SimpleExt.dll");
	if (hDLL != NULL)
	{
		lpfnDllRegisterServer = (HCRET)GetProcAddress(hDLL, "DllUnregister ");

		if(NULL == lpfnDllRegisterServer)
			MessageBox("ERR");
		else
		{
			if(FAILED((*lpfnDllRegisterServer)()))
				MessageBox("Dll registration failed!");
			else
				MessageBox("Registering DLL Success");
		}
		
		FreeLibrary ( hDLL );
	}
	else
		MessageBox("LoadLibrary failed");

But it is showing MessageBox("ERR"). (in BOLD)
What is the problem?

Thanks & Best Regards,
Aniket Salunkhe

Re: Unregister same registering with 'regsvr32.exe' ?

ThatsAlok19-Jul-06 4:48

ThatsAlok

19-Jul-06 4:48

Aniket Salunkhe wrote:
HCRET lpfnDllRegisterServer = NULL;

lpfnDllRegisterServer should of type :- HRESULT STDAPICALLTYPE DllUnregisterServer(void)

and

Aniket Salunkhe wrote:

lpfnDllRegisterServer = (HCRET)GetProcAddress(hDLL, "DllUnregister ");

pass DllUnregisterServer instead of DllUnregister

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
Support CRY- Child Relief and You

Re: Unregister same registering with 'regsvr32.exe' ?

Andy Rama19-Jul-06 20:26

Andy Rama

19-Jul-06 20:26

The dll I am tring to Unregister/Register in written by myself using 'ATL COM Appwizard' in VC6. But when I use other dll to register/unregister using following code, it is working. Then what might be the problem?
When I register/unregister other dll (not mine). using following code (code given by u). It is working fine. But same code for my dll is not working, that dll I can register/unregister using "regsvr32" command in command prompt. Then what might be the problem ?

typedef HRESULT (CALLBACK *HCRET)(void);

HCRET lpfnDllRegisterServer = NULL;
HINSTANCE hDLL = LoadLibrary("SimpleExt.dll");
if (hDLL != NULL)
{
lpfnDllRegisterServer = (HCRET)GetProcAddress(hDLL, "DllRegisterServer");
//lpfnDllRegisterServer = (HCRET)GetProcAddress(hDLL, "DllUnregisterServer");

if(NULL == lpfnDllRegisterServer)
MessageBox("ERR");
else
{
if(FAILED((*lpfnDllRegisterServer)()))
MessageBox("Dll registration failed!");
else
MessageBox("Success");
}
FreeLibrary ( hDLL );
}
else
MessageBox("LoadLibrary failed");

ThatsAlok wrote:
lpfnDllRegisterServer should of type :- HRESULT STDAPICALLTYPE DllUnregisterServer(void)

How to use this. I have declared it as,

typedef HRESULT (CALLBACK *HCRET)(void);
HCRET lpfnDllRegisterServer = NULL;

how to make a commandLine to wait

kanna_p17-Jul-06 20:24

kanna_p

17-Jul-06 20:24

Hello frnds.! Is it possible to make comnd prompt to wait until an exe finishes its execution..?

Re: how to make a commandLine to wait [modified]

bob1697217-Jul-06 20:33

bob16972

17-Jul-06 20:33

Are you spawning another exe? There are multiple version of the spawn and exec commands that include a variation that waits for the spawned exe to finish. Is that what your looking for or are you asking to keep the command window from a command line window open after some processing to view results?

If the latter, then put something like a getchar() in there to make it wait for a keypress...

int main(int argc, char* argv[])
{
// Processing here?

printf("Press a key to continue\n");
getchar();
return 0;
}

-- modified at 2:33 Tuesday 18th July, 2006

Re: how to make a commandLine to wait

NiceNaidu17-Jul-06 20:33

NiceNaidu

17-Jul-06 20:33

U can try Sleep()

Appu..
"If you judge people, you have no time to love them."

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.