Thread: Helper functions: design issue

Suppose I have a generally useful function declared in a header that relies on a number of helper functions which are not meant to be called by other functions. Where and how would it be recommended to declare the helper functions? Would there be any issues if they are declared in the implementation file (of the useful function) and not in the header?

I would generally declare and define the helper functions in the unnamed namespace of the implementation file, and not mention them at all in the header. I'm not entirely sure if that is best practice, though.

Normally, I would use the "Pascal" principle of putting the helper functions above the "external" function, e.g:

Code:

#include <somefunction.h>

static int helper1(...)
{
  ...
}

static int helper2(...)
{
...
}

int somefunction(...)
{
...
   x = helper1();
...
   y = helper2();
...
   return soemthing;
}

This is of course both a style issue, and other people may have other ideas of which order you place functions, etc. And if helper1 and helper2 are mutually recursive, then you will of course have to forward declare one to call it from the other.

By making the functions static, they are not "visible" to other functions.

--
Mats