function scope

[carmelo]

Hi, I wrote a program in c++ and it works. now i want to put all the
code in 1 file and leave in the main.cpp only a few things. In the
main I call a function that is in the other file but it doesn't work.
I tryed to declare the function extern, I tried to include an header
with the declaration, but the problem is always the same, error C2129:
static function 'void display(void)' declared but not defined. What
can I do?

[jason.cipriani@gmail.com]

Re: function scope

"carmelo" <carmelo.abramo @gmail.comwrote in message
news:cfa08981-
af30-4018-8d46-242f59fdf253@60 g200...le groups.com...

Hi, I wrote a program in c++ and it works. now i want to put all the
code in 1 file and leave in the main.cpp only a few things. In the
main I call a function that is in the other file but it doesn't work.
I tryed to declare the function extern, I tried to include an header
with the declaration, but the problem is always the same, error C2129:
static function 'void display(void)' declared but not defined. What
can I do?

When you declare/define a function as "static", that function is only
in scope in the file it is declared/defined in (and it is not exported
from that translation unit either). Don't declare it as static.

In the file you want to use display() in, declare it simply as:

void display (void);

And in the file that defines display, define it just like:

void display (void) {
// your code
}

The "extern" is implied on function declarations.

If you start using your display() function in more than one other
source file, eventually it becomes convenient to just stick the
declarations in a header file and #include that header in all the
source files you want to use display() in.

Jason

[tOmMy]

Re: function scope

Maybe，yo u can use "extern" keyword.

On Feb 27, 5:24 pm, carmelo <carmelo.abr... @gmail.comwrote :

Hi, I wrote a program in c++ and it works. now i want to put all the
code in 1 file and leave in the main.cpp only a few things. In the
main I call a function that is in the other file but it doesn't work.
I tryed to declare the function extern, I tried to include an header
with the declaration, but the problem is always the same, error C2129:
static function 'void display(void)' declared but not defined. What
can I do?

[carmelo]

Re: function scope

On 27 Feb, 10:32, "jason.cipri... @gmail.com"
<jason.cipri... @gmail.comwrote :

"carmelo" <carmelo.abr... @gmail.comwrote in message
>
news:cfa08981-
af30-4018-8d46-242f59fdf...@60 g2000hsy.google groups.com...
>

Hi, I wrote a program in c++ and it works. now i want to put all the
code in 1 file and leave in the main.cpp only a few things. In the
main I call a function that is in the other file but it doesn't work.
I tryed to declare the function extern, I tried to include an header
with the declaration, but the problem is always the same, error C2129:
static function 'void display(void)' declared but not defined. What
can I do?

>
When you declare/define a function as "static", that function is only
in scope in the file it is declared/defined in (and it is not exported
from that translation unit either). Don't declare it as static.
>
In the file you want to use display() in, declare it simply as:
>
void display (void);
>
And in the file that defines display, define it just like:
>
void display (void) {
// your code
>
}
>
The "extern" is implied on function declarations.
>
If you start using your display() function in more than one other
source file, eventually it becomes convenient to just stick the
declarations in a header file and #include that header in all the
source files you want to use display() in.
>
Jason

Thank you sooooooooooo much Jason! Now It works!!

[Victor Bazarov]

Re: function scope

jason.cipriani@ gmail.com wrote:

[..]
In the file you want to use display() in, declare it simply as:
>
void display (void);
>
And in the file that defines display, define it just like:
>
void display (void) {
// your code
}
[..]

A nit-pick. Consider abandoning the C-induced habit of
putting the keyword 'void' between parentheses in function
declarations. It is considered much better to write
_nothing_ in the argument list if it is to have _nothing_:

void display();
...
void display() {
// your code
}

V
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