Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.c > #8064

Re: flowto (Just for fun)

Show all headers | View raw

On 2011-07-10, Dr Nick <3-nospam@temporary-address.org.uk> wrote:
> Ike Naar <ike@sverige.freeshell.org> writes:
>
>> On 2011-07-10, Phil Carmody <thefatphil_demunged@yahoo.co.uk> wrote:
>>> gwowen <gwowen@gmail.com> writes:
>>>> On Jul 8, 12:39?am, Phil Carmody <thefatphil_demun...@yahoo.co.uk>
>>>> wrote:
>>>> 
>>>> > However, making it a solitary enum just to avoid making it a #define is
>>>> > nothing more than sophistry.
>>>> 
>>>> Scoping is not sophistry.
>>>
>>> You can make #defines disappear just as easily as enums, were that
>>> to be an issue.
>>
>> Actually, it can be a bit tricky to do it well.
>> Can you demonstrate how easily the enums can be replaced by #defines
>> in the program below?
>>
>> #include <assert.h>
>>
>> enum {value = 0};
>> int global = value;
>>
>> void foo(int, int);
>>
>> int main(void)
>> {
>>   enum {value = 1};
>>   foo(global, value);
>>   return 0;
>> }
>>
>> void foo(int i0, int i1)
>> {
>>   assert(i0 == value && i1 == 1);
>> }
>
> Sure:
>
> #define GLOBAL_DEFAULT 0
> #define APPROPRIATE_VALUE 1
>
> #include <assert.h>
>
> int global = GLOBAL_DEFAULT;
>
> void foo(int, int);
>
> int main(void)
> {
>    foo(global, APPROPRIATE_VALUE);
>    return 0;
> }
>
> void foo(int i0, int i1)
> {
>    assert(i0 == value && i1 == 1);
> }
>
> A heck of a lot less obfuscated as well!

Names were changed, and a local entity (``value'' inside main) was
moved to the global level. That's more than merely using #defines
instead of enums.

The small example may look obfuscated, but in a large program you
want to be able to use local names (e.g. restricted to a function
body) without running the risk of breaking things globally.

Your solution might break code that uses the name APPROPRIATE_VALUE
for other purposes.

Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar

Thread

Re: flowto (Just for fun) luser- -droog <mijoryx@yahoo.com> - 2011-07-07 00:03 -0700
  Re: flowto (Just for fun) Dr Nick <3-nospam@temporary-address.org.uk> - 2011-07-07 08:06 +0100
    Re: flowto (Just for fun) Shao Miller <sha0.miller@gmail.com> - 2011-07-07 19:34 -0400
    Re: flowto (Just for fun) Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-07-08 02:39 +0300
      Re: flowto (Just for fun) Keith Thompson <kst-u@mib.org> - 2011-07-07 17:09 -0700
      Re: flowto (Just for fun) gwowen <gwowen@gmail.com> - 2011-07-08 03:10 -0700
        Re: flowto (Just for fun) Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-07-10 04:44 +0300
          Re: flowto (Just for fun) Ike Naar <ike@sverige.freeshell.org> - 2011-07-10 08:51 +0000
            Re: flowto (Just for fun) Dr Nick <3-nospam@temporary-address.org.uk> - 2011-07-10 10:52 +0100
              Re: flowto (Just for fun) Ike Naar <ike@sverige.freeshell.org> - 2011-07-10 11:12 +0000
                Re: flowto (Just for fun) Dr Nick <3-nospam@temporary-address.org.uk> - 2011-07-10 12:15 +0100
                Re: flowto (Just for fun) Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-07-11 03:32 -0700
                Re: flowto (Just for fun) Dr Nick <3-nospam@temporary-address.org.uk> - 2011-07-11 20:11 +0100
            Re: flowto (Just for fun) Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-07-10 20:42 +0300
            Re: flowto (Just for fun) "io_x" <a@b.c.invalid> - 2011-07-11 08:08 +0200
    Re: flowto (Just for fun) luser- -droog <mijoryx@yahoo.com> - 2011-07-10 23:51 -0700
      Re: flowto (Just for fun) "io_x" <a@b.c.invalid> - 2011-07-11 09:15 +0200
  Re: flowto (Just for fun) "io_x" <a@b.c.invalid> - 2011-07-08 20:06 +0200

csiph-web