Thread: How to reference variables declared in codes from header file?

Hello,

I have some inline functions declared in the header file and need to access some variables declared in the codes that include the header file, is there a where to do so?

For example:

Code:

module.h:
inline t_print() { printf("modid = %d\n", modid); }

// this should print 1 or 2
inline some_func() { t_print(); };

module1.cpp:
static long modid = 1;
t_print();  // this should give modid = 1

module2.cpp:
static long modid = 2;
t_print(); // this should give modid = 2

Any suggestion out there? Thanks.

Thanks for the reply.

Yes, actually both modules in the example include module.h file. Then when module1.cpp calls some_func(), the printed line should be with "modid = 1"; and when module2.cpp calls some_func(), the printed line would be "modid = 2".

But since modids are declared as static in the cpp modules, they are not accessible in the header file. Thus the question is whether there is a way, or alternate solution to acheive the similar requirement?

Thanks again.

You should have some_func and t_print take modid as a parameter, that's what parameters are for.

Otherwise extern might work for you.

Yes, passing as argument would solve the situation. I guess that would be the only solution now. Initially the reason I wanted to use static in cpp module was to avoid passing as argument, the programmers need not know about the modid.

Thank you.

Don't complicate things just pass modid as a parameter to the function t_print(). Using global variables can be quite an inconvenience. Your best bet may be to go object oriented and store the globals in their separate modules. That's just a suggestion, though.