Re: private types

[Maciej Sobczak <no.spam@no.spam.com>]

Robert A Duff wrote:

>>>Only a very few C/C++ programmers
>>>actually master the language.
>>
>>As is true for any language that is at least moderately useful.
> 
> True.  Language designers ought to take that into account -- whenever
> possible, try to design features subtle misunderstandings are unlikely
> to cause bugs.

True, I don't have any doubts about it.

> Suppose an Ada programmer and a C++ programmer both think that null/NULL
> must be represented as all-zero-bits.  Both programmers are confused.

Both programmers take assumptions which are equally wrong.

> But which programmer is more likely to write code that won't work
> on a machine where the assumption turns out to be false?

Naither of those programmer should have any problems with their 
programs, because pointers are, well, pointers, not integers. Neither of 
them should have any temptation to interpret pointers as numbers, so 
that the actual "value" of the pointer never really matters. Even the 
question "is the NULL pointer zero?" makes no sense in this light, 
unless you target specific piece of silicon (see my replies to Martin 
Krischik).

In practice, in the world of pointers it's not the NULL pointer 
representation which is causing problems, but rather unconstrained 
pointer arithmetics.

-- 
Maciej Sobczak : http://www.msobczak.com/
Programming    : http://www.msobczak.com/prog/