All Questions
Tagged with pragma include-guards
14 questions
1
vote
0
answers
143
views
How to disable inclusion of header when using `#pragma once` (similiary to when using include guards)?
From time to time I have to retrofit unit testing into an unfriendly environment.
In these cases include guards are pretty useful, because:
I could suppress inclusion of unwanted header file,
I could ...
- 891
4
votes
3
answers
8k
views
#pragma once vs. include guards [duplicate]
I am going through Implementation defined behavior control
and there is the following text in relation to #pragma once:
Unlike header guards, this pragma makes it impossible to erroneously use the ...
- 1,053
0
votes
0
answers
61
views
pragma once or ifndef define endif [duplicate]
in header files we use pre-processor making an inclusion guards so in view of avoiding multiple header files inclusion so we write:
// mytest.h
#ifndef MY_TEST_H
#define MY_TEST_H
// code here
int ...
user6911618
1
vote
1
answer
261
views
Why are there no include guards in Numerical Recipes header files?
novice C++ programmer here.
I'm using Numerical Recipes (V3) source code as part of a larger, modulated C++ project.
While I'll try not to get into the specifics of my problem, I am curious as to ...
- 21
0
votes
2
answers
393
views
Understanding headers and include
I am trying to grasp how actually multiple definitions of include files collaborate and sometimes collide. So I have a custom header file file.h, where some functions are declared within an #include ...
- 4,743
23
votes
1
answer
10k
views
How to make CLion use "#pragma once" instead of "ifndef ... def ..." by default for new header files?
By default, CLion will add the following lines to a newly created header file:
#ifndef SOME_NAME_H
#define SOME_NAME_H
.... your code here
#endif //SOME_NAME_H
But I like #pragma once more. How can ...
- 20.6k
3
votes
2
answers
1k
views
Compiler does not support #pragma once
I have a compiler (PGI) that does not support
#pragma once
but the library (thrust) I would like to include uses them.
Is there a workaround for this problem?
- 163
6
votes
3
answers
8k
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When to use include guards or #pragma once C++ [closed]
Is it good practice to use your choice of either/both include guards and #pragma once in every header file, or just those with something such as a class declaration?
I am tempted to put it in every ...
- 3,316
3
votes
2
answers
172
views
Since other abusable but useful features have been standardized, why not #pragma once?
The nonstandard #pragma once feature is implemented on practically all C++ compilers, but the C++ standard excludes it.
The usual explanation of why #pragma once, or some language construct that does ...
- 14.4k
36
votes
3
answers
6k
views
Should I still use #include guards AND #pragma once?
http://en.wikipedia.org/wiki/Pragma_once
Should I still use include guards when all of these compilers support #pragma once?
A lot of responses on stack overflow say to use both for compatibility, but ...
- 37.7k
5
votes
2
answers
999
views
Does "#pragma once" have the potential to cause errors?
All of my header files use include guards as well as pragma once:
#pragma once
#ifndef FILE_NAME_H
#define FILE_NAME_H
class foo
{
//foo interface..
};
#endif /* FILE_NAME_H */
I understand ...
- 37.7k
5
votes
3
answers
4k
views
multiple definition and namespace
Is that the right way to have functions in namespace that i will #include in multiple files?
test.h
#pragma once
#ifndef TEST
#define TEST
namespace test{
namespace {
...
- 1,603
62
votes
9
answers
12k
views
Why isn't C/C++'s "#pragma once" an ISO standard?
I am currently working on a big project and maintaining all those include guards makes me crazy! Writing it by hand is frustrating waste of time. Although many editors can generate include guards this ...
- 8,683
444
votes
16
answers
256k
views
Is #pragma once a safe include guard?
I've read that there is some compiler optimization when using #pragma once which can result in faster compilation. I recognize that is non-standard, and thus could pose a cross-platform compatibility ...
- 15.8k