|
Hie all,
void max(void);
class B;
class A{
public:
B f;
};
class B
{
};
int main(int argc, char* argv[])
{
max();
return 0;
}
void max(void)
{
}
In the above code fragment.call to max is allowed..but the object f of class B inside class A is not allowed.Y it is so?
|
|
|
|
|
Till I interpret your Code is Alright,anyway which compiler are you using for compiling above.it's working fine on My Visual C++ 6.0 Sp5 compiler.
"I Think this Will Help"
[Vote One Here,.....]
<h5
alok gupta="" <br=""> visit me at http://www.thisisalok.tk
|
|
|
|
|
I am using VC 6.0 sp 5 only...It is not possible to compile this code correctly.
|
|
|
|
|
it is enable . I'm attempted .
|
|
|
|
|
At the point that you define class A the size of class B is not known.
Therefore, the compiler can not calculate the size of class A.
...cmk
Save the whales - collect the whole set
|
|
|
|
|
What about the function Max? Also is the size is the only factor matter here?
|
|
|
|
|
As all function pointers are the same size it knows the size of Max() - it is the size of a function pointer. 
On a subsequent pass, or at the linking stage, it can set the pointer to the appropriate value.
...cmk
Save the whales - collect the whole set
|
|
|
|
|
cmk wrote:
At the point that you define class A the size of class B is not known.
Therefore, the compiler can not calculate the size of class A.
Yeah You are Right!!, the compiler can't calculate the size of Class A, so instead of using the declare abive as this
class B;
class A
{
public:
B *f;
}
class B
{
};
this will work fine
"I Think this Will Help"
[Vote One Here,.....]
<h5
alok gupta="" <br=""> visit me at http://www.thisisalok.tk
|
|
|
|
|
Yes, or just define B before A as B will not likely have any reference to A.
Where two class' need to refer to each other one must include a pointer or reference, the other may include an instance, pointer or reference.
...cmk
Save the whales - collect the whole set
|
|
|
|
|
CMK says:
Where two class' need to refer to each other one must include a pointer or reference, the other may include an instance, pointer or reference.
This is not compulsory, I can define header file including total class prototype. rest class details can be in .cpp file.
|
|
|
|
|
Forward declarations can be tricky. You can do one of three things in this instance:
1) Make f a reference.
2) Make f a pointer.
3) Move class B above class A.
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
|
|
|
|
|
I am working with VC++ 5.0 and want to add DirectX support of playing AVI files. DirectX 9.0 SDK has already been installed and the directory options of VC++ have been correctly set. However, when i add #include "dshow.h" to the project and compile the source, I get this error:
E:\DXSDK\INCLUDE\strmif.h(28) : fatal error C1189: #error : this stub requires an updated version of <rpcndr.h>
Can anyone solve this?
<font=sans-serif>|-|3llo Wo|2ld
|
|
|
|
|
Anybody helps?
<font=sans-serif>|-|3llo Wo|2ld
|
|
|
|
|
Hi!
I'd like to make a login dialog box which needs to pop up right before NT own one appears.
As far as I know, once NT login box appears after booting up a system, I can use all Windows's API.
If you have any tip on it, please let me know.
|
|
|
|
|
|
Hi all,
I'm a home-based developer who has a single desktop machine with Visual SourceSafe 6 installed. I recently purchased a notebook.
I'd like to know how can I share a single codebase between the 2 computers, considering that they will not always be connected to each other. i.e. I want to be able to sync both machines, take my notebook offsite, make various code changes to the notebook's VSS database, and later reconnect the 2 machines and sync the changes with my desktop machine's VSS database.
Can I use XP Pro's Offline Files capabilities to keep both versions in sync? Is it safe to just sync the files under VSS\data? Does anyone have any alternative suggestions or caveats?
Many thanks,
Gary
|
|
|
|
|
I do not see how this situation differs from any other networked enviroment. My VSS database resides on a server machine in the computer room, and I check out files from my desktop. If my desktop loses its connection to the network, I can still work on those files and check them in when I am done (and the network connection has been restored). I do not need to keep a separate VSS database on my desktop.
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
|
|
|
|
|
I should have been more specific. Ideally I want to run VSS on the laptop so I can do several days of development (including being able to undo checkouts when I really screw things up) between syncs.
Gary
|
|
|
|
|
i need to be able to dial a phone number from my modem.
|
|
|
|
|
|
Using fprintf? Thanks
<italic>Work hard and a bit of luck is the key to success. You don`t need to be genius, to be rich.
|
|
|
|
|
Why are you using C instead of C++ ? Surely it would be easier to direct an ifstream to the printer ?
You can use any sort of output method you like to print, so long as you direct it to the print DC.
Christian
I have several lifelong friends that are New Yorkers but I have always gravitated toward the weirdo's. - Richard Stringer
|
|
|
|
|
My intention was to print like a DOS application would do? You know, like the printing output of a chashier machine. I hope you understand what I meant. I think, I got the wrong concept about this printing thing. Any idea how to print like the DOS? Do I have to code for that, or set the printer?
<italic>Work hard and a bit of luck is the key to success. You don`t need to be genius, to be rich.
|
|
|
|
|
You can open a file handle to the printer using "LPT1" as the file name in the fopen function.
FILE *pPrinter = fopen(_T("LPT1"), _T("w"));
if (pPrinter)
{
fprintf(pPrinter, _T("Hello World"));
}
"You're obviously a superstar." - Christian Graus about me - 12 Feb '03
"Obviously ??? You're definitely a superstar!!!" mYkel - 21 Jun '04
Within you lies the power for good - Use it!
Honoured as one of The Most Helpful Members of 2004
|
|
|
|
|
Thank you.
<italic>Work hard and a bit of luck is the key to success. You don`t need to be genius, to be rich.
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
