.h file supposed to be interface with extern functions; how to define in .cc file that includes the header?

Question

I have a function in my header file 1t.h that looks like the following:

extern int dthreads_libinit(dthreads_func_t func, void *arg);

I then want to implement that function in a separate file which includes 1t.h:

int dthreads_libinit(dthreads_funct_t func, void* arg) {
    //Do something here...
}

I get these errors though:

‘int dthreads_libinit’ redeclared as different kind of symbol'
error: previous declaration of ‘int dthreads_libinit(dthreads_func_t, void*)

What is wrong with what I am doing?

Answer 1

You have a typo in the signature of your function definition

 dthreads_libinit(dthreads_funct_t func, void* arg) {
                            // ^

If you correct this to

 dthreads_libinit(dthreads_func_t func, void* arg) {

as it's used for the func param in the function declaration

 extern int dthreads_libinit(dthreads_func_t func, void *arg);

the code compiles fine (no matter, wether g++ or gcc is used).