C / C++ / MFC

13-Mar-08 16:06

Hello everyone,

Here is the related C++ Spec and my test code. I think virtual base class, no matter direct virtual base class or not, will always be constructed before non-virtual class (including non-virtual direct base class), correct?

Another question is, what means "and only for the constructor of the most derived class as described below" in related Spec statements?

Spec:

--------------------
12.6.2 Initializing bases and members [class.base.init]

5 Initialization shall proceed in the following order:
— First, and only for the constructor of the most derived class as described below, virtual base classes shall
be initialized in the order they appear on a depth-first left-to-right traversal of the directed acyclic graph
of base classes, where “left-to-right” is the order of appearance of the base class names in the derived
class base-specifier-list.
— Then, direct base classes shall be initialized in declaration order as they appear in the base-specifier-list
(regardless of the order of the mem-initializers).
— Then, nonstatic data members shall be initialized in the order they were declared in the class definition
(again regardless of the order of the mem-initializers).
— Finally, the body of the constructor is executed.
[Note: the declaration order is mandated to ensure that base and member subobjects are destroyed in the
reverse order of initialization. ]
--------------------

/*
output
constructor B1
constructor B2
constructor D2
constructor D1
constructor D3
*/

#include <iostream>

using namespace std;

class B1 {
public:
	 B1()
	 {
		 cout << "constructor B1 " << endl;
	 }
};

class B2 {
public:
	 B2()
	 {
		 cout << "constructor B2 " << endl;
	 }
};

class D1 : virtual public B1 {
public:
	 D1()
	 {
		 cout << "constructor D1 " << endl;
	 }
};

class D2 : public virtual B1, public B2 {
public:
	 D2()
	 {
		 cout << "constructor D2 " << endl;
	 }
};

class D3 : public D1, virtual public D2 {
public:
	 D3()
	 {
		 cout << "constructor D3 " << endl;
	 }
};

int main()
{
	D3 d;
	return 0;
}

thanks in advance,
George

Eytukan13-Mar-08 16:25

13-Mar-08 16:25

Your free quesions limit has ended yesterday midnight. You need to start paying now. lol got late for my office, bug someone else till I comeback. Big Grin | :-D

Kid, I'm just joking. Dont take your 2.0 semi-automatic or 1.0 fully automatic guns. byebye Big Grin | :-D

OK,. what country just started work for the day ? The ASP.NET forum is flooded with retarded questions. -Christian Graus

Best wishes to Rexx[^]

George_George13-Mar-08 16:34

13-Mar-08 16:34

Thanks VuNic,

Your past and continue suppose are appreciated. Smile | :)

regards,
George

ThatsAlok13-Mar-08 19:54

ThatsAlok

13-Mar-08 19:54

VuNic wrote:
Dont take your 2.0 semi-automatic or 1.0 fully automatic guns. byebye

What about AK100, i have still that in possesion! and also i know your location Laugh | :laugh:

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
Never mind - my own stupidity is the source of every "problem" - Mixture

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

Hamid_RT23-Mar-08 1:16

Hamid_RT

23-Mar-08 1:16

See here[^] and here[^] for more info. Smile | :)

George_George23-Mar-08 3:15

How to get ALT, SHIFT and CTRL key?

23-Mar-08 3:15

Thanks Hamid,

Great link!

regards,
George

TooShy2Talk13-Mar-08 15:32

13-Mar-08 15:32

Hi,

I want to get ALT, SHIFT and CTRL key from keyboard.
Is it possible in OnKeyDown event?
How can I do it?

Hope you can help me.
Thanks.

Eytukan13-Mar-08 16:14

13-Mar-08 16:14

OnSysKeyDown

OK,. what country just started work for the day ? The ASP.NET forum is flooded with retarded questions. -Christian Graus

Best wishes to Rexx[^]

TooShy2Talk13-Mar-08 16:38

13-Mar-08 16:38

Thanks for the reply.

I think it's the same function as OnKeyDown().
Can I monitor SHIFT and CTRL with it?

Eytukan13-Mar-08 17:40

13-Mar-08 17:40

Sorry ignore my previous reply. It's for ATL combination keys.
Clickety[^]

OK,. what country just started work for the day ? The ASP.NET forum is flooded with retarded questions. -Christian Graus

Best wishes to Rexx[^]

Mahesh Kulkarni13-Mar-08 18:14

Mahesh Kulkarni

13-Mar-08 18:14

<code>
    BOOL bCtrl = ::GetKeyState(VK_CONTROL);
BOOL bAlt = ::GetKeyState(VK_SHIFT);
BOOL bShift = ::GetKeyState(VK_MENU);</code>

This will help you to know the combination keydown tracking.

The secret of life is not enjoyment
but education through experience.
- Swami Vivekananda.

ThatsAlok13-Mar-08 19:53

ThatsAlok

13-Mar-08 19:53

Mahesh Kulkarni wrote:
BOOL bCtrl = ::GetKeyState(VK_CONTROL); BOOL bAlt = ::GetKeyState(VK_SHIFT); BOOL bShift = ::GetKeyState(VK_MENU);

though it is the nice way to get key state, but you have poll this thing every time to get state of the key.,

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

Mahesh Kulkarni13-Mar-08 20:43

Mahesh Kulkarni

13-Mar-08 20:43

Yes alok I do agree with u.
But I got only this solution to do this....if any alternative for this please tell.

The secret of life is not enjoyment
but education through experience.
- Swami Vivekananda.

TooShy2Talk13-Mar-08 21:16

13-Mar-08 21:16

Thank you for the reply.
I will try this now.

TooShy2Talk13-Mar-08 21:40

13-Mar-08 21:40

I tried your code inside OnKeyDown() event but
the result is unpredictable.

if(::GetKeyState(VK_CONTROL))
AfxMessageBox(L"CONTROL");

if(::GetKeyState(VK_SHIFT))
AfxMessageBox(L"SHIFT");

if(::GetKeyState(VK_MENU))
AfxMessageBox(L"ALT");

When ALT is pressed, either no display or
wrong message(CONTROL or SHIFT)

CONTROL and SHIFT sometimes correct but
sometimes display all.

Did i do something wrong?
How will i use the code?

Pimpl Idiom client/serve compile/link

Mahesh Kulkarni14-Mar-08 2:40

Mahesh Kulkarni

14-Mar-08 2:40

Try this...

<code>
      BOOL bCtrl = ::GetKeyState(VK_CONTROL)& 0x8000;
      BOOL bShift = ::GetKeyState(VK_SHIFT)& 0x8000;
      BOOL bAlt = ::GetKeyState(VK_MENU)& 0x8000 ;	
</code>

The secret of life is not enjoyment
but education through experience.
- Swami Vivekananda.

George_George13-Mar-08 15:26

About your opaque pointer

13-Mar-08 15:26

Hello everyone,

Suppose in Pimpl Idiom, we put private members into Pimpl class (implementation class).

(http://www.gotw.ca/gotw/024.htm)

My questions are, if we changed the Pimpl class and do not change visible parts of the whole component (class). There are two parties, component and client. Inside the component, there are two parts, Pimpl part and visible (to client) part.

1. For the component, I think it needs re-compile, since private members of Pimpl part changed are referred by visible parts (public members refer to private members);

2. I am not sure whether for the whole component, it needs to relink? I think it depends on whether other compile unit of the component invokes functions from the Pimpl part of component? Is it correct?

3. I am not sure whether for the client, it needs re-link? If we provide the whole component as a static lib, client needs to re-link, right? And if we provide the whole component as a DLL, and client implicit links with it with import library, does the client needs relink again?

thanks in advance,
George

Eytukan13-Mar-08 16:08