473,396 Members | 2,010 Online
Bytes | Software Development & Data Engineering Community
Post Job

Home Posts Topics Members FAQ

Join Bytes to post your question to a community of 473,396 software developers and data experts.

What following statement means?

//a header file

#define API_ABC

//a CPP file

class API_ABC Myclass;
class Myclass{
......
};

What does "#define API_ABC" do when declaring a class(Myclass in this
case)? Why use it?

Thanks.

WM

Jul 23 '05 #1
2 1467
we*****@yahoo.com wrote:
//a header file

#define API_ABC

//a CPP file

class API_ABC Myclass;
class Myclass{
.....
};

What does "#define API_ABC" do when declaring a class(Myclass in this
case)? Why use it?


Why don't you ask the one who wrote it?

In some systems you're allowed to give additional qualifiers to any
symbol or class, like __declspec(dllexport) or some such nonsense.
Perhaps in some other incarnation of this code 'API_ABC' is actually
defined to expand into some kind of linkage specification...

V
Jul 23 '05 #2
In message <11**********************@z14g2000cwz.googlegroups .com>,
we*****@yahoo.com writes
//a header file

#define API_ABC

//a CPP file

class API_ABC Myclass;
class Myclass{
.....
};

What does "#define API_ABC" do when declaring a class(Myclass in this
case)?
Nothing, in this case.
Why use it?


(a) Maybe as a hint to the maintainer that the class is an abstract base
class needed for this application programming interface .

(b) In some programming environments the macro might be differently
defined, so it expands to some (non-standard) compiler- and
platform-dependent string which tells the compiler to do something
special with the class.

--
Richard Herring
Jul 23 '05 #3

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

220
by: Brandon J. Van Every | last post by:
What's better about Ruby than Python? I'm sure there's something. What is it? This is not a troll. I'm language shopping and I want people's answers. I don't know beans about Ruby or have...
54
by: Brandon J. Van Every | last post by:
I'm realizing I didn't frame my question well. What's ***TOTALLY COMPELLING*** about Ruby over Python? What makes you jump up in your chair and scream "Wow! Ruby has *that*? That is SO...
29
by: asj | last post by:
Can you guess what this is? http://www.blueboard.com/phone/apache_sept_2003.gif It's a history of the IIs "Titanic", which is being slowly and painfully sunk by the open source Apache web...
12
by: Steven T. Hatton | last post by:
This is something I've been looking at because it is central to a currently broken part of the KDevelop new application wizard. I'm not complaining about it being broken, It's a CVS images. ...
1
by: David | last post by:
I'm running into problems using XSD.exe to generate classes from XSD files using the <Include> functionality. Being a complete newbie with this, I am obviously missing something obvious I have...
12
by: prashna | last post by:
Hi all, I am new to C and I am working on some simple programs.I am getting the following warning which I am not able to find what it is, please let me know what is causing this warning.Also What...
4
by: Tina | last post by:
This is an issue regarding what exactly is accomplished by using "Protected" when defining a variable. It seems it does much more than just applying Protected status to a variable. I have an...
669
by: Xah Lee | last post by:
in March, i posted a essay “What is Expressiveness in a Computer Language”, archived at: http://xahlee.org/perl-python/what_is_expresiveness.html I was informed then that there is a academic...
11
by: antonyliu2002 | last post by:
I know that this has been asked and answered thousands of times. As a matter of fact, I know that I need to say If Not Page.IsPostBack Then 'Do something End If for things that needs to be...
38
by: Zytan | last post by:
What is the difference between these two lines? Dim args As Object() = New Object() {strText} Dim args As Object() = {strText} args seems usuable from either, say, like so: ...
0
by: Charles Arthur | last post by:
How do i turn on java script on a villaon, callus and itel keypad mobile phone
0
by: emmanuelkatto | last post by:
Hi All, I am Emmanuel katto from Uganda. I want to ask what challenges you've faced while migrating a website to cloud. Please let me know. Thanks! Emmanuel
0
BarryA
by: BarryA | last post by:
What are the essential steps and strategies outlined in the Data Structures and Algorithms (DSA) roadmap for aspiring data scientists? How can individuals effectively utilize this roadmap to progress...
1
by: Sonnysonu | last post by:
This is the data of csv file 1 2 3 1 2 3 1 2 3 1 2 3 2 3 2 3 3 the lengths should be different i have to store the data by column-wise with in the specific length. suppose the i have to...
0
marktang
by: marktang | last post by:
ONU (Optical Network Unit) is one of the key components for providing high-speed Internet services. Its primary function is to act as an endpoint device located at the user's premises. However,...
0
by: Hystou | last post by:
Most computers default to English, but sometimes we require a different language, especially when relocating. Forgot to request a specific language before your computer shipped? No problem! You can...
0
Oralloy
by: Oralloy | last post by:
Hello folks, I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>". The problem is that using the GNU compilers,...
0
jinu1996
by: jinu1996 | last post by:
In today's digital age, having a compelling online presence is paramount for businesses aiming to thrive in a competitive landscape. At the heart of this digital strategy lies an intricately woven...
0
tracyyun
by: tracyyun | last post by:
Dear forum friends, With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.