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by: Evan |
last post by:
Is there any standard for when to use #if
!defined(SOME_INCLUSION_GUARD) versus #ifndef SOME_INCLUSION_GUARD?
Aside from being able to combine multiple things into an #if, is there
any difference? My VC++ docs say that thay are equivalent, but is
there any convention on when to use one vs. another?
Also, how widely is #pragma once supported?
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by: prettysmurfed |
last post by:
Hi all
I have this, probably stupid question, how to avoid multiple
definitions when a header file is included more than once.
I thought, when you wrote the header-file and used the
ifndef/define directives, the code between the statements
define and endif was only compiled once. But this seems
to be incorrect, as I get a whole bunch of errors when
I compile the critter.
For example if I include header.h more than once the
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by: DrUg13 |
last post by:
#ifndef HEADER_H
#define HEADER_H
blah blal
#endif
So this tells the compiler That if its defined do not define it again.
Could someone help me understand this.
Does this mean that if I use the same clasee in two different classes
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by: Michael Sgier |
last post by:
Hello
I get the error below. But why and what does ifndef? Well what
is ifndef?
Many thanks and regards
Michael
error: syntax error before `(' token
#ifndef MD2SwapInt
static __inline__ Uint32 MD2SwapInt(Uint32 D) {
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by: John Hanley |
last post by:
I have a program where both my main.c and program.c files use the program.h
file. So I #include "program.h" in both the .c files. The program.h file
has
#ifndef PROGRAM_H
#define PROGRAM_H
....
#endif
Yet when I build my program, the DJGPP compiler tells me there are multiple
definitions of each of my functions.
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by: Qiao Jian |
last post by:
I am new to c. Today I just read an h file within which there is statements:
#ifndef _RANDOM_H
#define _RANDOM_H
So what is the meaning or purpose of this statement?
When should I use such statement in my own program?
Thank you so much!
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by: vfunc |
last post by:
Despite a #ifndef I am getting a redefinition error
The offending .h file looks like the following
#ifndef DISTRIB_H
#define DISTRIB_H
double dblpi; // this is getting compiled twice
etc...
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by: canoewhiteh2o |
last post by:
I am converting a couple of C header files to C#. It is mainly just a
bunch C structs but I am not sure how to handle the #ifdef and #ifndef
in C#. For example:
#ifndef DATE_TIME
#define DATE_TIME unsigned long
#endif // NOT DATE_TIME
The #define DATE_TIME I am handling with:
public const UInt32 DATE_TIME;
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by: Johs |
last post by:
Each time I make a new .h file in eclipse it starts with this:
#ifndef FUNCS_H_
#define FUNCS_H_
// here goes all the code
#endif /*FUNCS_H_*/
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by: Studlyami |
last post by:
Okay I have been wondering this for a while now. I am a little confused on the difference between these two defines #pragma once & #ifndef.
From my understanding #pragma is compiler dependent, meaning that it will be handled differently depending on the compiler? #ifndef is not dependent on the compiler.
So from that i take it that its more universal to use #ifndef because its the standard, but if I use #pragma once in visual...
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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 effortlessly switch the default language on Windows 10 without reinstalling. I'll walk you through it.
First, let's disable language synchronization. With a Microsoft account, language settings sync across devices. To prevent any complications,...
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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 tapestry of website design and digital marketing. It's not merely about having a website; it's about crafting an immersive digital experience that captivates audiences and drives business growth.
The Art of Business Website Design
Your website is...
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by: Hystou |
last post by:
Overview:
Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows Update option using the Control Panel or Settings app; it automatically checks for updates and installs any it finds, whether you like it or not. For most users, this new feature is actually very convenient. If you want to control the update process,...
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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 protocol has its own unique characteristics and advantages, but as a user who is planning to build a smart home system, I am a bit confused by the choice of these technologies. I'm particularly interested in Zigbee because I've heard it does some...
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by: isladogs |
last post by:
The next Access Europe User Group meeting will be on Wednesday 1 May 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM).
In this session, we are pleased to welcome a new presenter, Adolph Dupré who will be discussing some powerful techniques for using class modules.
He will explain when you may want to use classes instead of User Defined Types (UDT). For example, to manage the data in unbound forms.
Adolph will...
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by: conductexam |
last post by:
I have .net C# application in which I am extracting data from word file and save it in database particularly. To store word all data as it is I am converting the whole word file firstly in HTML and then checking html paragraph one by one.
At the time of converting from word file to html my equations which are in the word document file was convert into image.
Globals.ThisAddIn.Application.ActiveDocument.Select();...
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by: TSSRALBI |
last post by:
Hello
I'm a network technician in training and I need your help.
I am currently learning how to create and manage the different types of VPNs and I have a question about LAN-to-LAN VPNs.
The last exercise I practiced was to create a LAN-to-LAN VPN between two Pfsense firewalls, by using IPSEC protocols.
I succeeded, with both firewalls in the same network. But I'm wondering if it's possible to do the same thing, with 2 Pfsense firewalls...
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by: 6302768590 |
last post by:
Hai team
i want code for transfer the data from one system to another through IP address by using C# our system has to for every 5mins then we have to update the data what the data is updated we have to send another system
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by: muto222 |
last post by:
How can i add a mobile payment intergratation into php mysql website.
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