Re: Pass by Reference Function Question

"Robbie Hatley" <>
Fri, 11 Apr 2008 16:29:19 -0700
Bryan Parkoff asked:

    I write my large project in C++ source code. My C++ source code
contains approximate four thousand small functions. Most of them are

Ewww. Don't do that. If these functions are all doing nearly
the same thing (as I very much suspect), replace those 4000
functions with maybe 7 or 13 or 21 functions taking arguments
(passed by value or by reference, maybe returning a value and
maybe not, as the problem demands) to configure their behavior.

The whole idea of functions is STRUCTURE. That means top-level
functions call mid-level functions, and mid-level functions
call bottom-level functions. Having 4000 tiny, nearly-identical
bottom-level functions is a design nightmare.

I define variables and functions in the global scope.

Don't define variables at the global scope. Period.

The global variables and global functions are hidden to prevent
from accessing by the programmers. All global functions share
global variables.

I don't see how you can make global variables "hidden",
unless you make them file-static, so that only one translation
unit sees them.

If you need data hiding (encapsulation), define your objects
either on the stack (local, "auto") in functions, or dynamically
(using new and delete).

You can still allow one function to have read/write access to
local variables in another function by passing arguments by
non-const reference, like so:

void function2 (double & asdf) // NON-CONST REF!!!!!
   asdf *= 2.0; // alters "trouble" in function1 below

int function1 (void)
   double trouble = 47;
   function2(trouble); // double trouble (pardon pun)
   std::cout << trouble << std::endl; // prints 94
   return 42;

    Only very few global functions are allowed to be reusability for the
programmers to use. Few global functions access most hidden functions
during the time execution.
    My question is -- do you think that pass by reference is really
necessary? Pass by reference is necessary unless you want to reuse function
with the choice of global / local variables. Please advise.

Passing by non-const reference is the only way I know of that
one function can alter local variables in another function.
I use it a lot in my C++ programming. I try for ZERO global
variables. I often don't quite make it, electing to have
2 or 3 global variables, if they truly are used by a lot of
different functions. But that's really just laziness on my
part; it *could* all be done with non-const refs instead.

Robbie Hatley
lonewolf aatt well dott com
www dott well dott com slant user slant lonewolf slant

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