Subj : Re: Any help on why?
To   : borland.public.cpp.borlandcpp
From : Bob Gonder
Date : Thu Jul 08 2004 04:09 pm

Thomas Maeder [TeamB] wrote:
>Bob Gonder  writes:
>
>>> In contrary to your code, mine is at least correct.
>>
>> Not quite, yours is also wrong-endian on Win/Intel.
>
>Mine is endianness agnostic.

Don't see how that can be.
>>>>>unsigned char const *const begin(reinterpret_cast<unsigned char *>(&d));
This returns the lowest address (the  LSB) of d.
(MSB in BigEndian, right?)

>>>>>unsigned char const *const end(begin + sizeof d);
This returns the address 1 past d (1 past MSB)
(Again, LSB in BigEndian, right?)

>>>>>for (unsigned char const *c = begin; c!=end; ++c)
This outputs data LSB-to-MSB, which is backwards for a hex value.

In BigEndian, it would output MSB-to-LSB, which is the normal way to
display a hex value.

For  long d = 0x12345678
Your output for LittleEndian would be
78563412
For Big Endian it would be
12345678

Hardly agnostic (or correct)

We weren't talking hex dumps here (for which your code is fine), we
were talking %x replacements for displaying hex values. For that, your
code is broken.

>>>>>double d(3.11415);
>>>>>unsigned char const *const begin(reinterpret_cast<unsigned char *>(&d));
>>>>>unsigned char const *const end(begin + sizeof d);
>>>>>for (unsigned char const *c = begin; c!=end; ++c)
>>
>> Should be   c=end-1, c>= begin; --c
>
>That would have undefined behavior when c is moved to begin-1.

Could be, but I'd do it completely different anyway.
probably closer to c=end;do{--c;use c;}while(c != begin)
And, being a library subroutine, I'd switch it, along with all my file
and screen io routines, when changing platforms. I have no
expectations that my libraries will survive intact when platforms
collide.  But, I'm trying to improve my applications so they rely on
library code instead of platform code.

>> Go along with that, but maybe better would be to fire those inept
>> programmers (or retrain them).
>
>After all these things you posted in this thread, I doubt that you are in
>a position to ask somebody else to get retrained, I'm afraid.

But then, I'm not the code snob that abhors "inappropriate" usage.
_If_ I were, I wouldn't look to ISO to "fix" the language, I'd "fix"
the programmers.  The language was just fine, thankyouverymuch.

I do try to look ahead to 64, perhaps 128 bit x86 platforms, but I
don't see worrying about Motorola or other cross-platform issues.
It just isn't important to me, nor I'd think to most non-academics.
Maybe large enterprises worry, but then they worry about lots of
things that don't affect normal people.

.