Mixing
How can you access the function from another translation unit without including any files?
I was reading about static functions and it was said that if the function is static then you can use it only in the same file. After testing it, I realized it is not true because if you include the file with a static function you can still use that function in another file. Then I read a clarification that you can actually use static function only in the same translation unit. Ok, that makes sense because it means .cpp + includes, but even if the function is not static, you will still not be able to use it unless you include the file. So how is it even possible to access a function from another translation unit in the first place without including anything, what is the point of static functions?
Main.cpp
#include "Staticf.h"
void main()
{
visible();
}
Staticf.h
#pragma once
#include <iostream>
using namespace std;
static void visible()
{
cout << "Static function is visiblen";
}
This compiles alright. If I make that function non-static and remove #include "Staticf.h" I will not be able to use it in Main anyways. So why are static functions needed if you can't access non-static as well?
c++ static-functions
asked Nov 20 '18 at 18:33
VegetaVegeta
4616
add a comment |
I was reading about static functions and it was said that if the function is static then you can use it only in the same file. After testing it, I realized it is not true because if you include the file with a static function you can still use that function in another file. Then I read a clarification that you can actually use static function only in the same translation unit. Ok, that makes sense because it means .cpp + includes, but even if the function is not static, you will still not be able to use it unless you include the file. So how is it even possible to access a function from another translation unit in the first place without including anything, what is the point of static functions?
Main.cpp
#include "Staticf.h"
void main()
{
visible();
}
Staticf.h
#pragma once
#include <iostream>
using namespace std;
static void visible()
{
cout << "Static function is visiblen";
}
This compiles alright. If I make that function non-static and remove #include "Staticf.h" I will not be able to use it in Main anyways. So why are static functions needed if you can't access non-static as well?
c++ static-functions
asked Nov 20 '18 at 18:33
VegetaVegeta
4616
1
If you include something, the included file and the file that includes it are the same file.
– Neil Butterworth
Nov 20 '18 at 18:35
Yes, I know that, that was not the question
– Vegeta
Nov 20 '18 at 18:41
What is the point of calling someone that you don't know their address, name and phone number?
– Ostrich Groomer
Nov 20 '18 at 18:42
#include <iostream> using namespace std; is the worst path you can take on in a header file.
– πάντα ῥεῖ
Nov 20 '18 at 18:42
FWIW, this is a hold over from C. In C++ if you want to hide a function you can use a namespace.
– NathanOliver
Nov 20 '18 at 18:43
add a comment |
I was reading about static functions and it was said that if the function is static then you can use it only in the same file. After testing it, I realized it is not true because if you include the file with a static function you can still use that function in another file. Then I read a clarification that you can actually use static function only in the same translation unit. Ok, that makes sense because it means .cpp + includes, but even if the function is not static, you will still not be able to use it unless you include the file. So how is it even possible to access a function from another translation unit in the first place without including anything, what is the point of static functions?
Main.cpp
#include "Staticf.h"
void main()
{
visible();
}
Staticf.h
#pragma once
#include <iostream>
using namespace std;
static void visible()
{
cout << "Static function is visiblen";
}
This compiles alright. If I make that function non-static and remove #include "Staticf.h" I will not be able to use it in Main anyways. So why are static functions needed if you can't access non-static as well?
c++ static-functions
asked Nov 20 '18 at 18:33
VegetaVegeta
4616
I was reading about static functions and it was said that if the function is static then you can use it only in the same file. After testing it, I realized it is not true because if you include the file with a static function you can still use that function in another file. Then I read a clarification that you can actually use static function only in the same translation unit. Ok, that makes sense because it means .cpp + includes, but even if the function is not static, you will still not be able to use it unless you include the file. So how is it even possible to access a function from another translation unit in the first place without including anything, what is the point of static functions?
Main.cpp
#include "Staticf.h"
void main()
{
visible();
}
Staticf.h
#pragma once
#include <iostream>
using namespace std;
static void visible()
{
cout << "Static function is visiblen";
}
This compiles alright. If I make that function non-static and remove #include "Staticf.h" I will not be able to use it in Main anyways. So why are static functions needed if you can't access non-static as well?
c++ static-functions
c++ static-functions
asked Nov 20 '18 at 18:33
VegetaVegeta
4616
asked Nov 20 '18 at 18:33
VegetaVegeta
4616
edited Nov 20 '18 at 18:38
Vegeta
asked Nov 20 '18 at 18:33
VegetaVegeta
4616
asked Nov 20 '18 at 18:33
VegetaVegeta
4616
asked Nov 20 '18 at 18:33
VegetaVegeta
4616
4616
1
If you include something, the included file and the file that includes it are the same file.
– Neil Butterworth
Nov 20 '18 at 18:35
Yes, I know that, that was not the question
– Vegeta
Nov 20 '18 at 18:41
What is the point of calling someone that you don't know their address, name and phone number?
– Ostrich Groomer
Nov 20 '18 at 18:42
#include <iostream> using namespace std; is the worst path you can take on in a header file.
– πάντα ῥεῖ
Nov 20 '18 at 18:42
FWIW, this is a hold over from C. In C++ if you want to hide a function you can use a namespace.
– NathanOliver
Nov 20 '18 at 18:43
add a comment |
1
If you include something, the included file and the file that includes it are the same file.
– Neil Butterworth
Nov 20 '18 at 18:35
Yes, I know that, that was not the question
– Vegeta
Nov 20 '18 at 18:41
What is the point of calling someone that you don't know their address, name and phone number?
– Ostrich Groomer
Nov 20 '18 at 18:42
#include <iostream> using namespace std; is the worst path you can take on in a header file.
– πάντα ῥεῖ
Nov 20 '18 at 18:42
FWIW, this is a hold over from C. In C++ if you want to hide a function you can use a namespace.
– NathanOliver
Nov 20 '18 at 18:43
1
1
If you include something, the included file and the file that includes it are the same file.
– Neil Butterworth
Nov 20 '18 at 18:35
If you include something, the included file and the file that includes it are the same file.
– Neil Butterworth
Nov 20 '18 at 18:35
Yes, I know that, that was not the question
– Vegeta
Nov 20 '18 at 18:41
Yes, I know that, that was not the question
– Vegeta
Nov 20 '18 at 18:41
What is the point of calling someone that you don't know their address, name and phone number?
– Ostrich Groomer
Nov 20 '18 at 18:42
What is the point of calling someone that you don't know their address, name and phone number?
– Ostrich Groomer
Nov 20 '18 at 18:42
#include <iostream> using namespace std; is the worst path you can take on in a header file.– πάντα ῥεῖ
Nov 20 '18 at 18:42
#include <iostream> using namespace std; is the worst path you can take on in a header file.– πάντα ῥεῖ
Nov 20 '18 at 18:42
FWIW, this is a hold over from C. In C++ if you want to hide a function you can use a namespace.
– NathanOliver
Nov 20 '18 at 18:43
FWIW, this is a hold over from C. In C++ if you want to hide a function you can use a namespace.
– NathanOliver
Nov 20 '18 at 18:43
add a comment |
2 Answers
2
active
oldest
votes
You can access non-static functions from other translation units. You just need a forward declaration:
somemodule.cpp
void func()
{
// details
}
main.cpp
void func();
int main()
{
func();
}
It is, of course, a best practice to put the forward declaration in a header file.
So what use are static functions?
In modern C++, they actually aren't much use. static is a feature C++ inherited from C. In C, declaring a helper function static is actually pretty useful because C doesn't have namespaces. You can use static to eliminate the chance of name collisions between your private helper functions and the private helper functions in other translation units. In C++, it's generally preferred to wrap your private helpers in a class or anonymous namespace.
answered Nov 20 '18 at 18:42
Peter RudermanPeter Ruderman
10.2k2352
You could mention OOP for your C++ section =)
– Chris Mc
Nov 20 '18 at 18:48
Thanks, I tested it and this answered my question. I didn't think about forward declaration
– Vegeta
Nov 20 '18 at 18:50
add a comment |
If the function is static (as if free static function), you cannot access it from another translation unit.
Remove the static, and if you can't include a header (you probably can though... change the former static function's header), add a prototype in the file.
answered Nov 20 '18 at 18:35
Matthieu BrucherMatthieu Brucher
14.9k32140
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
You can access non-static functions from other translation units. You just need a forward declaration:
somemodule.cpp
void func()
{
// details
}
main.cpp
void func();
int main()
{
func();
}
It is, of course, a best practice to put the forward declaration in a header file.
So what use are static functions?
In modern C++, they actually aren't much use. static is a feature C++ inherited from C. In C, declaring a helper function static is actually pretty useful because C doesn't have namespaces. You can use static to eliminate the chance of name collisions between your private helper functions and the private helper functions in other translation units. In C++, it's generally preferred to wrap your private helpers in a class or anonymous namespace.
answered Nov 20 '18 at 18:42
Peter RudermanPeter Ruderman
10.2k2352
You could mention OOP for your C++ section =)
– Chris Mc
Nov 20 '18 at 18:48
Thanks, I tested it and this answered my question. I didn't think about forward declaration
– Vegeta
Nov 20 '18 at 18:50
add a comment |
You can access non-static functions from other translation units. You just need a forward declaration:
somemodule.cpp
void func()
{
// details
}
main.cpp
void func();
int main()
{
func();
}
It is, of course, a best practice to put the forward declaration in a header file.
So what use are static functions?
In modern C++, they actually aren't much use. static is a feature C++ inherited from C. In C, declaring a helper function static is actually pretty useful because C doesn't have namespaces. You can use static to eliminate the chance of name collisions between your private helper functions and the private helper functions in other translation units. In C++, it's generally preferred to wrap your private helpers in a class or anonymous namespace.
answered Nov 20 '18 at 18:42
Peter RudermanPeter Ruderman
10.2k2352
You could mention OOP for your C++ section =)
– Chris Mc
Nov 20 '18 at 18:48
Thanks, I tested it and this answered my question. I didn't think about forward declaration
– Vegeta
Nov 20 '18 at 18:50
add a comment |
You can access non-static functions from other translation units. You just need a forward declaration:
somemodule.cpp
void func()
{
// details
}
main.cpp
void func();
int main()
{
func();
}
It is, of course, a best practice to put the forward declaration in a header file.
So what use are static functions?
In modern C++, they actually aren't much use. static is a feature C++ inherited from C. In C, declaring a helper function static is actually pretty useful because C doesn't have namespaces. You can use static to eliminate the chance of name collisions between your private helper functions and the private helper functions in other translation units. In C++, it's generally preferred to wrap your private helpers in a class or anonymous namespace.
answered Nov 20 '18 at 18:42
Peter RudermanPeter Ruderman
10.2k2352
You can access non-static functions from other translation units. You just need a forward declaration:
somemodule.cpp
void func()
{
// details
}
main.cpp
void func();
int main()
{
func();
}
It is, of course, a best practice to put the forward declaration in a header file.
So what use are static functions?
In modern C++, they actually aren't much use. static is a feature C++ inherited from C. In C, declaring a helper function static is actually pretty useful because C doesn't have namespaces. You can use static to eliminate the chance of name collisions between your private helper functions and the private helper functions in other translation units. In C++, it's generally preferred to wrap your private helpers in a class or anonymous namespace.
answered Nov 20 '18 at 18:42
Peter RudermanPeter Ruderman
10.2k2352
answered Nov 20 '18 at 18:42
Peter RudermanPeter Ruderman
10.2k2352
answered Nov 20 '18 at 18:42
Peter RudermanPeter Ruderman
10.2k2352
answered Nov 20 '18 at 18:42
Peter RudermanPeter Ruderman
10.2k2352
10.2k2352
You could mention OOP for your C++ section =)
– Chris Mc
Nov 20 '18 at 18:48
Thanks, I tested it and this answered my question. I didn't think about forward declaration
– Vegeta
Nov 20 '18 at 18:50
add a comment |
You could mention OOP for your C++ section =)
– Chris Mc
Nov 20 '18 at 18:48
Thanks, I tested it and this answered my question. I didn't think about forward declaration
– Vegeta
Nov 20 '18 at 18:50
You could mention OOP for your C++ section =)
– Chris Mc
Nov 20 '18 at 18:48
You could mention OOP for your C++ section =)
– Chris Mc
Nov 20 '18 at 18:48
Thanks, I tested it and this answered my question. I didn't think about forward declaration
– Vegeta
Nov 20 '18 at 18:50
Thanks, I tested it and this answered my question. I didn't think about forward declaration
– Vegeta
Nov 20 '18 at 18:50
add a comment |
If the function is static (as if free static function), you cannot access it from another translation unit.
Remove the static, and if you can't include a header (you probably can though... change the former static function's header), add a prototype in the file.
answered Nov 20 '18 at 18:35
Matthieu BrucherMatthieu Brucher
14.9k32140
add a comment |
If the function is static (as if free static function), you cannot access it from another translation unit.
Remove the static, and if you can't include a header (you probably can though... change the former static function's header), add a prototype in the file.
answered Nov 20 '18 at 18:35
Matthieu BrucherMatthieu Brucher
14.9k32140
add a comment |
If the function is static (as if free static function), you cannot access it from another translation unit.
Remove the static, and if you can't include a header (you probably can though... change the former static function's header), add a prototype in the file.
answered Nov 20 '18 at 18:35
Matthieu BrucherMatthieu Brucher
14.9k32140
If the function is static (as if free static function), you cannot access it from another translation unit.
Remove the static, and if you can't include a header (you probably can though... change the former static function's header), add a prototype in the file.
answered Nov 20 '18 at 18:35
Matthieu BrucherMatthieu Brucher
14.9k32140
answered Nov 20 '18 at 18:35
Matthieu BrucherMatthieu Brucher
14.9k32140
answered Nov 20 '18 at 18:35
Matthieu BrucherMatthieu Brucher
14.9k32140
answered Nov 20 '18 at 18:35
Matthieu BrucherMatthieu Brucher
14.9k32140
14.9k32140
add a comment |
add a comment |
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1
If you include something, the included file and the file that includes it are the same file.
– Neil Butterworth
Nov 20 '18 at 18:35
Yes, I know that, that was not the question
– Vegeta
Nov 20 '18 at 18:41
What is the point of calling someone that you don't know their address, name and phone number?
– Ostrich Groomer
Nov 20 '18 at 18:42
#include <iostream> using namespace std; is the worst path you can take on in a header file.– πάντα ῥεῖ
Nov 20 '18 at 18:42
FWIW, this is a hold over from C. In C++ if you want to hide a function you can use a namespace.
– NathanOliver
Nov 20 '18 at 18:43