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http://www.artima.com/intv/goldilocks.html[^]
I especially liked the section "Climbing Above C-Level."
Stroustrup: "The C++ community has yet to internalize the facilities offered by standard C++. By reconsidering the style of C++ use, major improvements in ease of writing, correctness, maintainability, and efficiency can be obtained."
This is all too true. And it certainly applies to the code I'm having to maintain at the moment. It also applies to almost all the C++ code I've had to maintain over the past few years. Part of the problem has been that Standard C++ (STL, etc.) was difficult and certainly when STL was new it was pretty damn difficult to get to grips with. I remember at one time seeing the theoretical document behind the original HP (I think it was HP?) implementation and being completely bamboozled.
However, today there are plenty of good books around so current C++ developers should have no excuse for avoiding it (though Francis Glassborow of The Association of C and C++ Users tells me that the majority of professional programmers don't read books on programming so this may have something to do with it). Sure Standard C++ is big and does get pretty complicated but in fact basic use of it is easy and can alleviate a lot of common problems. There are lots of worked examples in, e.g., the MS Visual C++ online help. That was my first route into it.
Stroustrup: "Most of these techniques are criticized unfairly for being inefficient. The assumption is that if it is elegant, if it is higher level, it must be slow. It could be slow in a few cases, so deal with those few cases at the lower level, but start at a higher level. In some cases, you simply don't have the overhead. For example, vectors really are as fast as arrays. "
This too rings true. C/C++ developers are often obsessed with perceived inefficiency and often have poor intuition about it. Some time ago I read a case study on the use of Eiffel at a Fortune 500 storage manufacturer. Eiffel is an OO language analogous to Java and C# (i.e., managed runtime, etc.). The project required rewriting an existing C application in Eiffel. The developers were new to Eiffel and had the intuition that performance would be inferior as a result of Eiffel's managed runtime. In fact, it turned out that the new application was 10 times faster. Obviously, much of this performance boost would have been due to moving to a more efficient OO design, resulting in more code re-use. Also, no doubt the C application would have been faster than the original had it been redesigned in C. Still, it showed up the poor intuition of the C developers. We should aim first at maintainability and correctness. Efficiency will often follow as a consequence.
Kevin
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Dear developers,
One never knows to what edge freelance development can take you, like it did to me now all desperate to find a database implementation for embedded systems that are not .NET or 0x86 compatible. I have a pure C/C++ portable platform for some sort of programmable terminals, and I need a more or less generic implementation of a simple database, preferably with indexes or some sort of optimization. Any table is deemed to never have more than 1000 records. And the entire database is best residing in a single file. It’s killing me to think that these progressing days I would have to marvel it all on my own like in old times.
One last detail: It would be the nicest implementation with file-access level implemented clearly, like a driver so that I could just insert my own file-access operations that will work for me.
Anyone who has whatever relevant please, throw at me, be endlessly grateful for that.
Regards,
Just one of you.
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Hi all,
I am using the following code:
CArray<int,int> myArray;
for (int i=0;i < 10;i++)
myArray.Add(i);
myArray.RemoveAt(5);
TRACE(_T("\n"));
for ( i = 0; i < myArray.GetSize(); i++)
{
TRACE(_T("%d\n"),myArray.GetAt(i));
}
TRACE(_T("size is : %d"),myArray.GetSize());
TRACE(_T("\n"));
myArray.SetAtGrow(5,200);
for ( i = 0; i < myArray.GetSize(); i++)
{
TRACE(_T("%d\n"),myArray.GetAt(i));
}
TRACE(_T("size is : %d\n\n"),myArray.GetSize());
problem is, both sizes are 9 in the debug output window....
and for the second time i print the array i see that 200 is instead of 6 and not 5!!!??????
can any1 help here?
thanks
Yaron
Ask not what your application can do for you,
Ask what you can do for your application
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Yep pretty normal... SetAtGrow only increases the size if the index specified is bigger than the actual size... I bet you need InsertAt rather than SetAtGrow
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hi,
thanks for reply,
i've managed with SetAt instead of remove and then setatgrow....
thanks
Yaron
Ask not what your application can do for you,
Ask what you can do for your application
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Hi ive got app with Static splitter window. On each pane there is a listctrl (classic file explorer). When i first start my app i cant get any item focused even if i use SetActivePane and SetItemState. The same problem i have when i try to change view with tab key. The pane is active (or i quess so) but no list member is activated till i mouse click on it.
Can u help me plz ? Thanks in advance.
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im making a mp3 player and i want to get the end o the music to pass to the next music in the list
im actually doing this:
while(MCIWndGetPosition(m_Video) == MCIWndGetEnd(m_Video))
{
::MessageBox(m_Video,"PING","PING",MB_OK);
}
but when the end position ends it doesnt return the testing message box
please somebody help me resolving this issue
Regards
AI_Warrior
Portugal;P
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lol?
what you have here means that the program will loop THROUGH the message box until the end is reached.
once the message box shows, the execution stops here!
if you want to do it that way, it has to look like:
while( player_online )
{
play_next_track();
while( MCIWndGetPosition(m_Video) != MCIWndGetEnd(m_Video) )
Sleep( 1 );
}
but i don't know if this is the optimal way... i propose to use an existing mp3 player, until you've learned how it works the best way!
Don't try it, just do it! 
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Hi, how could I send a click through SendMessae or PostMessage ?? I want to use it with a parent window, this way:
CWnd* pWnd = GetParent()
pWnd->SendMessage(/* I don't know where I must send this and how */);
Thanks in advance. 
MaestroProgramador.Com
I didn't fail hundred times, I found hundred ways that didn't work.
No fallé cien veces, encontré cien maneras de que no funcionara.
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Click what, a button?
I case of button:
pWnd->SendMessage(WM_COMMAND,MAKEWORD(::GetDlgCtrlID(wndButton),BN_CLICKED),(LPARAM)wndButton);
regards
modified 12-Sep-18 21:01pm.
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For example, a listctrl is parent of a progress bar into it. I want when click on the progress bar to send the clic to the clistctrl that created it, that way. I would like to want how to send the click and where... I mean, where (HWND...).
Thanks in advance.
Rafael Fernández López.
I didn't fail hundred times, I found hundred ways that didn't work.
No fallé cien veces, encontré cien maneras de que no funcionara.
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Thanks mike for replying my message but what I wanted to know (and still don't know) is how to post the message.
<br />
CWnd* pWnd = GetParent();<br />
<br />
pWnd->SendMessage();<br />
Thanks everyone !!
Rafael Fernández López.
I didn't fail hundred times, I found hundred ways that didn't work.
No fallé cien veces, encontré cien maneras de que no funcionara.
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Yes, that's what I want to do, but I don't know the syntax of SendMessage. Could you type an example please ?
Thank you.
Rafael Fernández López.
I didn't fail hundred times, I found hundred ways that didn't work.
No fallé cien veces, encontré cien maneras de que no funcionara.
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From MSDN:
CWnd::SendMessage<br />
LRESULT SendMessage( UINT message, WPARAM wParam = 0, LPARAM lParam = 0 );<br />
...<br />
Sends the specified message to this window. The SendMessage member function calls the window procedure directly and does not return until that window procedure has processed the message.
So in your case it would be
GetParent->SendMessage(WM_LBUTTONDOWN, vkeystatus, MAKELPARAM(x,y) );
GetParent->SendMessage(WM_LBUTTONUP, vkeystatus, MAKELPARAM(x,y) );
HTH
“Our solar system is Jupiter and a bunch of junk” - Charley Lineweaver 2002
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Thank you Jonas Larsson, Mike and Greg for your help. It was very useful.
Rafael Fernández López.
I didn't fail hundred times, I found hundred ways that didn't work.
No fallé cien veces, encontré cien maneras de que no funcionara.
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Hi guys,
I think this is an embarassingly dumb question but it's causing me grief so I thought I'd ask for help.
I have 2 list boxes in a modal dialog. I know how to fill them using AddString() just find but this relies on having created the dialog with Create() then accessing. When I create the dialog using DoModal() how/where/when do I use AddString()?
Any help much appreciated.
S
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Hi,
since it is a Modal Dialog initialize the List Ctrl in the OnInitDialog() method.....
something like this:
BOOL CYourDlg::OnInitDialog()
{
CDialog::OnInitDialog();
m_FirstList.AddString(...);
m_SecondList.AddString(...);
...
...
}
hope this helps ya
Yaron
Ask not what your application can do for you,
Ask what you can do for your application
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Cheers Yaron ... thanks a lot man, it worked first time.
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i have a query: i use a dialog to take in user input for a rect dimensions but i tested it using AfxMessagebox and encounter assertion error, may i know where is the problem? i have a variable m_length of float type.
void Dialog :: OnOK
{
UpdateData(TRUE);
float length=m_length;
AfxMessageBox(length);
}
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Hi,
this could occur due to several problems:
1) look in the DDX method of the class that the m_length is defined there.
if it is not than the UpdataData(TRUE) will not be valid for m_length.
2) use format string for the float variable as follows:
CString szLength;
szLength.Format(_T("%d"),m_length);
AfxMessageBox(length);
hope this helps ya
Yaron
Ask not what your application can do for you,
Ask what you can do for your application
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the DDX method shows:
DDX_Text(pDX, IDC_LENGTH, m_length);
does that mean that the UpDateData(TRUE) is unable to take in the float m_length? i need my member variables to be float preferably because i am using it for OpenGL rendering and as i encountered problems putting my variables into OpenGl that why i was testing to check whether my function can take in the float values.... is there a better way?
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ok, i see the problem now...
open the class wizard (CTRL+W) and go to the definition of IDC_LENGTH and delete the m_str_length member. add a new member called m_length which will be not from CString type but from float type. then you should see an entry in the DDX as follows:
DDX_Text(pDX, IDC_LENGTH, m_length);
now the update data will hold the number within the m_length...and all u have to do is convert it to string and display it....
hope this helps ya
Yaron
Ask not what your application can do for you,
Ask what you can do for your application
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erm okie thanx but actually i made a typo error in my earlier message, it is really DDX_Text(pDX, IDC_LENGTH, m_length) already.. so that means AfxMessageBox cannot display a float directly? need to convert to String?
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