Re: C2512 - No default constructor available [modified] - C / C++ / MFC Discussion Boards

Re: C2512 - No default constructor available [modified]

Sarath C16-Jul-06 5:28

16-Jul-06 5:28

there's no default constructor defined in your class. you should pass the bool value to the CSentenceArray class.
i.e the implementation code of CSentenceList constructor, you should pass teh bool value to as initialization list

CSentenceList::CSentenceList(bool bCreateArray) : CSentenceArray(bCreateArray)
{
}

hope it's clear

SaRath.

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-- modified at 11:28 Sunday 16th July, 2006

Re: C2512 - No default constructor available

jon-8016-Jul-06 6:05

jon-80

16-Jul-06 6:05

I think that's what I'm doing actually...

#include "StdAfx.h"
#include ".\sentencelist.h"

CSentenceList::CSentenceList(bool bCreateArray) : CSentenceArray(bCreateArray)
{//Code}

CSentenceList::~CSentenceList ()
{}

Error:

error C2512: 'CSentenceArray' : no appropriate default constructor available
error C2436: 'CSentenceArray' : member function or nested class in constructor initializer list

Jon

Re: C2512 - No default constructor available

bob1697216-Jul-06 6:37

bob16972

16-Jul-06 6:37

Make sure you have the equivalent of a default destructor by giving the parameters of your constructor default values. "C++ will not attempt to create a default constructor for you if you declare one" (Effective C++ Third Edition - Scott Meyers)

Try this in your declaration in the header file...
CSentenceList(bool bCreateArray=false);

Re: C2512 - No default constructor available

jon-8016-Jul-06 6:46

jon-80

16-Jul-06 6:46

I tried adding a default value, even in the base class, but it's still unsuccessful.

CSentenceList::CSentenceList(bool bCreateArray = false) : CSentenceArray(bCreateArray = false)
{int x = NULL;}

CSentenceList::~CSentenceList ()
{}

Jon

Re: C2512 - No default constructor available

bob1697216-Jul-06 6:49

bob16972

16-Jul-06 6:49

No, your putting it in the implementation section.

Put it only in the declaration in the header file.

Re: C2512 - No default constructor available

David Crow17-Jul-06 3:24

David Crow

17-Jul-06 3:24

jon_80 wrote:

I think that's what I'm doing actually...

Not per the code you've shown. The compiler is telling you exactly what the problem is. CSentenceArray has no default constructor.

class CSentenceArray
{
public:
    CSentenceArray( void );
};

"Money talks. When my money starts to talk, I get a bill to shut it up." - Frank

"Judge not by the eye but by the heart." - Native American Proverb

Re: C2512 - No default constructor available

Mike Dimmick16-Jul-06 6:44

Mike Dimmick

16-Jul-06 6:44

You have declared a function called CSentenceArray in the CSentenceList class. I suspect this is hiding the CSentenceArray class constructor. Remove or rename this function, I'm pretty sure this is illegal anyway and you're just getting a poor diagnostic message from the compiler.

Stability. What an interesting concept. -- Chris Maunder

Re: C2512 - No default constructor available [modified]

bob1697216-Jul-06 6:53

bob16972

16-Jul-06 6:53

Thats just passing the parameter to the base class which is correct, otherwise the base class will not get any parameters to initialize with. The class declaration shows CSentenceList is derived from CSentenceArray...

class CSentenceList :
// Sentences stored as a linked list
public CSentenceArray

-- modified at 12:57 Sunday 16th July, 2006

Oh crud, I just spotted what you were talking about. I missed that the first time around. You are right. That doesn't look quite right...

protected:
void CSentenceArray(bool bCreateArray);
virtual void storeSentence(const char *pszSentence);
virtual void swapWithNext();
virtual int HowManyWords(const char *pszWord);
};

-- modified at 13:01 Sunday 16th July, 2006

How to convert this c++ code to javascript/html form?

L33VaNcL33F16-Jul-06 3:21

L33VaNcL33F

16-Jul-06 3:21

Hi everybody,
My question is how to convert this c++ code to javascript or html that can generate the result random number?

#include <cstdlib> 
#include <ctime> 
#include <iostream>

using std::cout;

int main( ) {

  // srand will set a random starting point for rand()
  // We use the time as a seed, as it's always changing
  srand( ( unsigned )time( 0 ) ); 

  // We generate a random number between 0 and 4013
  // 4013 because ( 22423 * 4013 => 89983499 and
  // 89983499 + 10016486 => 99999985 - our max value )
  int randomKey = rand() % 4013; 

  // Output the generated key and don't immediately close the command prompt window
  cout << "Your random key is: " << ( 10016486 + ( randomKey * 22423 ) ) << "\n"; 
  system( "PAUSE" );

  return 0;
}

Thanks for any help

Re: How to convert this c++ code to javascript/html form?

Justin Tay16-Jul-06 3:33

Justin Tay

16-Jul-06 3:33

Googling "javascript random" yields this[^] as the first result...

error C2259: : cannot instantiate abstract class

RockyJames16-Jul-06 1:35

RockyJames

16-Jul-06 1:35

Hi,
i have developed COM componet,its a custom Component,it supports ConnectionPoints,the Conntection interface is dervied from IUnknown.In the Client Side i have imported tlb file,I have wrote class CSink:_ISampleEvents

CSink psink;
psink = new CSink;

the following error is occuring
error C2259: : cannot instantiate abstract class

why..? how to avoid it,what could be the reason?

Thanks in before
james

Re: error C2259: : cannot instantiate abstract class

vecodo_doon16-Jul-06 3:26

vecodo_doon

16-Jul-06 3:26

CSink psink; //should be CSink* psink?

you'd better check the class CSink and make sure that
the CSink impliment all the virtual functions whose it's drivied from

hi

Re: error C2259: : cannot instantiate abstract class

Taka Muraoka16-Jul-06 3:28

Taka Muraoka

16-Jul-06 3:28

An abstract class is one that has one or more pure virtual functions defined. The intent is that you derive from that class and provide actual implementations for each of these functions. You can't instantiate a class that has a pure virtual function defined (since if you called it, the computer wouldn't knnow what to do) so the error message you're getting indicates that you've missed (at least) one.

0 bottles of beer on the wall, 0 bottles of beer, you take 1 down, pass it around, 4294967295 bottles of beer on the wall.

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Re: error C2259: : cannot instantiate abstract class

RockyJames16-Jul-06 3:42

RockyJames

16-Jul-06 3:42

yeah i have overridden all the pure virtual function`s in the derived class,and wrote their implementation,even then i am getting error..

Re: error C2259: : cannot instantiate abstract class

Taka Muraoka16-Jul-06 4:02

Taka Muraoka

16-Jul-06 4:02

You have to check all the way up the hierarchy. Maybe you're deriving from a class that is derived from a class that is derived from a class that still has a pure virtual function Smile | :)

The error message is definitely caused by this (although vecodo_doon's comment may well be the cause as well).

Re: error C2259: : cannot instantiate abstract class

Mike Dimmick16-Jul-06 7:23

Mike Dimmick

16-Jul-06 7:23

Have you implemented all of IUnknown's methods?

If you're using ATL's support by deriving from CComObjectRoot(Ex), the class you declare is not complete - it still has some abstract methods. You have to make use of the CComObject family of templates (CComObject, CComAggObject, CComPolyObject, CComObjectStack) to actually create an instance. The ATL implementation of the class factory does this for you, depending on which DECLARE_AGGREGATABLE macro you used.

Stability. What an interesting concept. -- Chris Maunder

steps for connection with server?

With_problem16-Jul-06 1:15

With_problem

16-Jul-06 1:15

if i want to get connected with server what r the minimum requirment.Other then port number what should i need.From where to start....

Re: steps for connection with server?

Mike Dimmick16-Jul-06 6:48

Mike Dimmick

16-Jul-06 6:48

This is such an open-ended question it's hard to know what to do with it. What protocol do you want to use? What sort of server?

The only link I can give you is the Winsock Programmer's FAQ[^], which might help a little.

Stability. What an interesting concept. -- Chris Maunder

Re: steps for connection with server?

ThatsAlok16-Jul-06 22:40

ThatsAlok

16-Jul-06 22:40

priyanka s wrote:
f i want to get connected with server what r the minimum requirmen

HI Priyanka,
here is solution for your Problem :-
http://codeproject.com/internet/#Client%2FServer+Development[^]

"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: steps for connection with server?

David Crow17-Jul-06 3:27

David Crow

17-Jul-06 3:27

You can connect to a remote machine (e.g., server) with a UNC path. Since you give no supporting information, a more detailed answer is not possible.

"Money talks. When my money starts to talk, I get a bill to shut it up." - Frank

"Judge not by the eye but by the heart." - Native American Proverb

Problem with 2D Graph ActiveX Control [modified]

Semion_N16-Jul-06 0:43

Semion_N

16-Jul-06 0:43

Hello,
I have a problem with more than one graph creation.
I added an element:

<br />
m_Graph.AddElement();<br />

than I wrote this line

<br />
m_Graph.PlotXY( i , pointsArray[i] ,arrIndex);<br />

the arrIndex=1
But it says that the element not found!
Here is a link to the article:
http://www.codeproject.com/miscctrl/ntgraph_activex.asp[^]

SnaidiS(Semion)

-- modified at 6:46 Sunday 16th July, 2006

Re: Problem with 2D Graph ActiveX Control

Semion_N16-Jul-06 4:12

Semion_N

16-Jul-06 4:12

please, I need some help

SnaidiS(Semion)

Re: Problem with 2D Graph ActiveX Control

Semion_N16-Jul-06 8:18

Semion_N

16-Jul-06 8:18

why nobody helps me?

SnaidiS(Semion)

Saving a BITMAP on disc

snir_ya15-Jul-06 23:49