C / C++ / MFC Discussion Boards

help with "error C2533: constructors not allowed a return type"

limesp27-Jul-08 23:21

27-Jul-08 23:21

Hi,

Q1.
I renamed my class name from FRWS to HELPER in order to combine all my "helper" classs into one HELPER CLASS; otherwise I will have a lot of small classes and long list of imports.

when I compile my prog, I get this error:
error C2533: 'FRWS::{ctor}' : constructors not allowed a return type

Q2.
When I try to use this object in the main program,

FRWS Sbj;

i get these errors:-
error C2065: 'FRWS' : undeclared identifier
error C2146: syntax error : missing ';' before identifier 'Sbj'

Enclose is the code:-
[HELPER.H was formally FRWS.H]
[contains 2 different classes]
#pragma once

class FRWS {
public:
FRWS(void);
virtual ~FRWS(void);
public:
CString ETEXT(CString givenTEXT);
CString DTEXT(CString givenTEXT);
};

class pgLog {
public:
pgLog(void);
virtual ~pgLog(void);

public:
void WLog( CString TF, CString LgText );
}

[THIS IS HELPER.CPP]
#include "StdAfx.h"
#include "Helper.h"

FRWS::FRWS(void) {
}

FRWS::~FRWS(void) {
}

CString FRWS::ETEXT(CString givenTEXT){
...
}

CString FRWS::DTEXT(CString givenTEXT){
...
}

void pgLOG::WLog( CString TF, CString LgText ){
...
}

Re: help with "error C2533: constructors not allowed a return type"

Matthew Faithfull28-Jul-08 0:12

Matthew Faithfull

28-Jul-08 0:12

I think your pgLog class is missing a ; after its final bracket. The compiler usually picks this up specifically but for some reason not in this case so the following function is being stuffed.

"The secret of happiness is freedom, and the secret of freedom, courage."
Thucydides (B.C. 460-400)

Nothing to see here - just realized Mr Faithfull already answered

enhzflep28-Jul-08 0:31

enhzflep

28-Jul-08 0:31

Although your style of questioning is interesting - as in, you don't ask any Poke tongue | ;-P

I think you'll find that your class pgLog doesn't have a ; after the last brace.. This may well be the cause of both errors. Leaving the ; off the end of a class definition causes the compiler to talk in tongues at times.

Re: Nothing to see here - just realized Mr Faithfull already answered

limesp28-Jul-08 0:35

limesp

28-Jul-08 0:35

Thanks.

Found that out too.

Alt+tab

mailtochandra2000@yahoo.com27-Jul-08 23:00

mailtochandra2000@yahoo.com

27-Jul-08 23:00

I having my own desktop application and iam launching many application through the desktop application and i required to display only the application which are launched through the desktop application when Alt+tab is pressed

can you pls help me...

Re: Alt+tab [modified]

enhzflep28-Jul-08 0:41

enhzflep

28-Jul-08 0:41

I can think of one way, but my mere mention of it will cause many seasoned ~~reasons~~ readers much anguish.

It's not elegant, and it very definitely is a hack however, ever noticed that if you create an app that has a toolbox window style that you (a) can't see it on the task-bar and (b) can't activate it through the usual alt-tab mechanism?

Think with me here - you can enumerate all windows, you can also change window styles.....

modified on Tuesday, July 29, 2008 7:59 AM

Hierachy Chart for MFC8.0?

Priya_Sundar27-Jul-08 22:31

Priya_Sundar

27-Jul-08 22:31

Hi All,

I need the link to the Hierachy chart for MFC8.0.

I tried to google and searched in MSDN also. But couldnt find it.

Please help!

Priya Sundar

Re: Hierachy Chart for MFC8.0?

Rajesh R Subramanian27-Jul-08 22:42

Rajesh R Subramanian

27-Jul-08 22:42

Priya_Sundar wrote:
I tried to google and searched in MSDN also. But couldnt find it.

It could be a bug in the documentation. They might have missed it out!

If you need the chart for version 9, it's here[^].

The three part chart after you've installed the feature pack for VS 2008 is here[^] (the PDF version of the same is available for download here[^])

Nobody can give you wiser advice than yourself. - Cicero
.·´¯`·->Rajesh<-·´¯`·.

Microsoft MVP - Visual C++[^]

Re: Hierachy Chart for MFC8.0?

Hamid_RT28-Jul-08 3:03

Hamid_RT

28-Jul-08 3:03

Do you need to Microsoft Foundation class Library version 9.0?

Busy Waiting

Daniel Kanev7-Mar-17 10:45

Daniel Kanev

7-Mar-17 10:45

I have read many articles about 'Busy Waiting' prevention in thread synchronization.
I am wondering if busy waiting is really a big problem with processors available nowadays.
What is your opinion - is busy waiting just a theoretical problem or it really affects system performance?

Thank you.

Re: Busy Waiting

CPallini27-Jul-08 22:33

CPallini

27-Jul-08 22:33

Daniel Kanev wrote:
I am wondering if busy waiting is really a big problem with processors available nowadays.

IMHO wasting time is an issue regardless of processor speed.
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

Re: Busy Waiting

Cedric Moonen28-Jul-08 2:05

Cedric Moonen

28-Jul-08 2:05

Daniel Kanev wrote:
I am wondering if busy waiting is really a big problem with processors available nowadays

Suppose that you have a loop in which you constantly check the value of a variable (and do something if the variable is true), no sleep or wait, only an 'endless' loop. This loop will consume the maximum resources it can use on the processor on which it is running. So, even if you have a faster processor, you will only loop faster. But all other process will still be slowed down because of that. So, yes, busy waiting is bad, even if you have the fastest processor in the world.

Cédric Moonen
Software developer

Charting control [v1.4]
OpenGL game tutorial in C++

Re: Busy Waiting

Stephen Hewitt28-Jul-08 14:29

Stephen Hewitt

28-Jul-08 14:29

Yes, it's a big problem on a multitasking OS.

Steve

What's the differences between lstrlen and _tcslen?

fantasy121527-Jul-08 22:14

fantasy1215

27-Jul-08 22:14

Looking into the MSDN, found the functions of lstrlen and _tcslen are the same,
If _tcslen is enough, why does lstrlen exist?
Please help me unlock my mind!

Re: What's the differences between lstrlen and _tcslen?

_AnsHUMAN_ 27-Jul-08 22:34

_AnsHUMAN_

27-Jul-08 22:34

When your project settings are MBCS, tcslen and lstrlen are same. You
should not use lstrlen on a UNICODE string. _tcslen will work on a
UNICODE string as well as MBCS.
If you dont know what MBCS/UNICODE are, use _tcslen

Somethings seem HARD to do, until we know how to do them.
Wink | ;-)

_AnShUmAn_

_beginthread issue

Programm3r27-Jul-08 21:45

Programm3r

27-Jul-08 21:45

Hi all,

When I try to use the _beginthread method, I receive the following error: error C2664: '_beginthread' : cannot convert parameter 1 from 'void (__stdcall *)(void *)' to 'void (__cdecl *)(void *)'

Function definition: void performActionsOnReader(void* par)
Begin Thread Call: _beginthread(performActionsOnReader, 0, NULL);

It's a dll project with the following preprocessors:

#ifdef STATIC_LIBRARY
  #define DLL_IMPORT_EXPORT
#else
  #ifdef WIN32
    #ifdef DLL_SOURCE_CODE
       #define DLL_IMPORT_EXPORT __declspec(dllexport) __stdcall
    #else
       #define DLL_IMPORT_EXPORT __declspec(dllimport) __stdcall
    #endif
  #else
    #define DLL_IMPORT_EXPORT FAR PASCAL
  #endif
#endif

#ifdef __cplusplus
  #define NoMangle extern "C"
#else
  #define NoMangle
#endif

Could the preproccesors cause the problem or am I doing something wrong?

The only programmers that are better that C programmers are those who code in 1's and 0's Green Alien | [Alien]

Programm3r
My Blog: ^_^

Re: _beginthread issue

CPallini27-Jul-08 22:22

CPallini

27-Jul-08 22:22

The error occurs since the exported function use the __stdcall linkage while _beginthread expects the __cdecl one (see, for instance [^]). As a workaround your application may wrap the DLL function, for instance:

// client side (i.e. the application)
void wrapPerformActionsOnReader(void* par)
{
  // invoke the DLL function.
  performActionsOnReader(par);
}

and then pass the wrapper to _beginthread.
Smile | :)

Re: _beginthread issue

Programm3r27-Jul-08 22:48

Programm3r

27-Jul-08 22:48

Thanks for the help Smile | :)

The only programmers that are better that C programmers are those who code in 1's and 0's Green Alien | [Alien]

Programm3r
My Blog: ^_^

You are welcome.

CPallini27-Jul-08 23:13

CPallini

27-Jul-08 23:13

Comparison between MFC6.0 and MFC8.0

Priya_Sundar27-Jul-08 21:09

Priya_Sundar

27-Jul-08 21:09

Hi All,

Can anyone tell me some links that tell the differences or comparision between MFC6 and MFC8?

I tried to google, but couldnt find it.

Kindly help!

Priya Sundar

Re: Comparison between MFC6.0 and MFC8.0

_AnsHUMAN_ 27-Jul-08 21:42

_AnsHUMAN_

27-Jul-08 21:42

Priya_Sundar wrote:
MFC6 and MFC8?

Do you mean VS6.0 and VS8.0
AFAIK there is nothing like MFC6 or MFC8 that may be the reason you don't find anything on google related with it

Somethings seem HARD to do, until we know how to do them.
Wink | ;-)

_AnShUmAn_

Re: Comparison between MFC6.0 and MFC8.0

Rajesh R Subramanian27-Jul-08 21:48

Rajesh R Subramanian

27-Jul-08 21:48

_AnShUmAn_ wrote:
AFAIK there is nothing like MFC6 or MFC8

*sigh*

Actually, there *is* MFC 6.0 and MFC 8.0

Nobody can give you wiser advice than yourself. - Cicero
.·´¯`·->Rajesh<-·´¯`·.

Microsoft MVP - Visual C++[^]

Re: Comparison between MFC6.0 and MFC8.0

_AnsHUMAN_ 27-Jul-08 22:16

_AnsHUMAN_

27-Jul-08 22:16

Thanks for the update.

Somethings seem HARD to do, until we know how to do them.
Wink | ;-)

_AnShUmAn_

Re: Comparison between MFC6.0 and MFC8.0

Rajesh R Subramanian27-Jul-08 22:23

Rajesh R Subramanian

27-Jul-08 22:23

No, that wasn't an update; it didn't happen all of a sudden - those versions of MFC were already existent. Having worked on MFC for several years (your profile), I was shocked you didn't know it. I would guess that you probably were emphasizing more on Win32, ATL or something else. Smile | :)

Nobody can give you wiser advice than yourself. - Cicero
.·´¯`·->Rajesh<-·´¯`·.

Microsoft MVP - Visual C++[^]

Re: Comparison between MFC6.0 and MFC8.0 [modified]

_AnsHUMAN_ 27-Jul-08 22:29

_AnsHUMAN_

27-Jul-08 22:29

ATL/COM. On another note I like to see and build code in MFC .

Somethings seem HARD to do, until we know how to do them.
Wink | ;-)

_AnShUmAn_

modified on Monday, July 28, 2008 4:47 AM

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