Velocity Reviews - Computer Hardware Reviews

Velocity Reviews > Newsgroups > Programming > C++ > Types defined in std::

Reply
Thread Tools

Types defined in std::

 
 
Andy Skypeck
Guest
Posts: n/a
 
      12-04-2003
I am looking for some validation against a dubious coding practice
that prevails where I work. C types defined in types.h (Linux) or
stdint.h (Windows, C99?) are used as if they belong to the C++
standard namespace.

std::uint8_t instead of uint8_t
std::uint32_t instead of uint32_t
....

I don't think the use of std:: is correct. Nowhere are these types
explicitly added to the std namespace. In fact GCC 3.3 fails on them.
Neither are they among the types defined in the C++ standard language
support files listed on page 433 in Stroustrup (2nd Ed.)

std::size_t
std:trdiff_t
std::NULL

defined in <cstddef> are ok. I am wrong about this?
 
Reply With Quote
 
 
 
 
tom_usenet
Guest
Posts: n/a
 
      12-04-2003
On 4 Dec 2003 07:09:30 -0800, http://www.velocityreviews.com/forums/(E-Mail Removed) (Andy Skypeck)
wrote:

>I am looking for some validation against a dubious coding practice
>that prevails where I work. C types defined in types.h (Linux) or
>stdint.h (Windows, C99?) are used as if they belong to the C++
>standard namespace.
>
>std::uint8_t instead of uint8_t
>std::uint32_t instead of uint32_t
>...
>
>I don't think the use of std:: is correct. Nowhere are these types
>explicitly added to the std namespace. In fact GCC 3.3 fails on them.
> Neither are they among the types defined in the C++ standard language
>support files listed on page 433 in Stroustrup (2nd Ed.)
>
>std::size_t
>std:trdiff_t
>std::NULL
>
>defined in <cstddef> are ok. I am wrong about this?


No, they aren't standard types in C++. They are standard in C99
though. But since C99 doesn't have namespaces, std::uint8_t has never
existed. std::uint8_t will probably become part of C++0x, whenever
that is ratified (around 2007-8 I suspect), and it may be part of the
standard library extension before that. Some compilers may be
pre-empting that by providing the standard types, but it isn't yet
standard.

Tom

C++ FAQ: http://www.parashift.com/c++-faq-lite/
C FAQ: http://www.eskimo.com/~scs/C-faq/top.html
 
Reply With Quote
 
 
 
 
Victor Bazarov
Guest
Posts: n/a
 
      12-04-2003
"Andy Skypeck" <(E-Mail Removed)> wrote...
> I am looking for some validation against a dubious coding practice
> that prevails where I work.


Take my word for it: it's better to go with the flow than against
it. Whether your coding practice is dubious or not, it's accepted
in the organisation, and you should do the same if you want to keep
your job.

> C types defined in types.h (Linux) or
> stdint.h (Windows, C99?) are used as if they belong to the C++
> standard namespace.
>
> std::uint8_t instead of uint8_t
> std::uint32_t instead of uint32_t
> ...
>
> I don't think the use of std:: is correct. Nowhere are these types
> explicitly added to the std namespace.


What do you mean by that?

> In fact GCC 3.3 fails on them.


So? How is that proof of anything?

> Neither are they among the types defined in the C++ standard language
> support files listed on page 433 in Stroustrup (2nd Ed.)
>
> std::size_t
> std:trdiff_t
> std::NULL
>
> defined in <cstddef> are ok. I am wrong about this?


NULL is a macro, it cannot be defined in a namespace. The Standard
says (17.4.1.1):

"1 The C++ Standard Library provides definitions for the following
types of entities: Macros, Values, Types, Templates, Classes,
Functions, Objects.

2 All library entities except macros, operator new and operator
delete are defined within the namespace std or namespaces nested
within namespace std."

Now, there is a subclause that says "It is undefined for a C++
program to add declarations or definitions to namespace std [...]"
but it could be argued that types you listed (uint8_t, etc.) are
part of the library implementation and as such belong to std...

Why don't you ask your development supervisor where they get those
types? They will probably be able to explain why 'std::' is used
there.

Victor


 
Reply With Quote
 
Dan W.
Guest
Posts: n/a
 
      12-04-2003
On 4 Dec 2003 07:09:30 -0800, (E-Mail Removed) (Andy Skypeck)
>I don't think the use of std:: is correct. Nowhere are these types
>explicitly added to the std namespace. In fact GCC 3.3 fails on them.


I don't think that use of the ::std namespace is an official stamp of
approval. Take std::hashmap, for example: This is a container that's
been living in ::std for quite a while, even though it is not yet part
of the standard.
 
Reply With Quote
 
Andy Skypeck
Guest
Posts: n/a
 
      12-05-2003
"Victor Bazarov" <(E-Mail Removed)> wrote in message news:<KuJzb.418968$HS4.3341510@attbi_s01>...
> "Andy Skypeck" <(E-Mail Removed)> wrote...
> > I am looking for some validation against a dubious coding practice
> > that prevails where I work.

>
> Take my word for it: it's better to go with the flow than against
> it. Whether your coding practice is dubious or not, it's accepted
> in the organisation, and you should do the same if you want to keep
> your job.


The organisation touts itself as a quality driven "six sigma"
environment. It seeks to write portable, robust, correct C++
code. Questioning what to me seems to be an incorrect
practice is very much in the spirit of the organisation.
Correctness should win out.

> > C types defined in types.h (Linux) or
> > stdint.h (Windows, C99?) are used as if they belong to the C++
> > standard namespace.
> >
> > std::uint8_t instead of uint8_t
> > std::uint32_t instead of uint32_t
> > ...
> >
> > I don't think the use of std:: is correct. Nowhere are these types
> > explicitly added to the std namespace.

>
> What do you mean by that?
>
> > In fact GCC 3.3 fails on them.

> So? How is that proof of anything?


The release notes for GCC-3.3 discuss types included in std::

> > Neither are they among the types defined in the C++ standard language
> > support files listed on page 433 in Stroustrup (2nd Ed.)
> >
> > std::size_t
> > std:trdiff_t
> > std::NULL
> >
> > defined in <cstddef> are ok. I am wrong about this?

>
> NULL is a macro, it cannot be defined in a namespace. The Standard
> says (17.4.1.1):


I stand corrected on NULL.

> Now, there is a subclause that says "It is undefined for a C++
> program to add declarations or definitions to namespace std [...]"
> but it could be argued that types you listed (uint8_t, etc.) are
> part of the library implementation and as such belong to std...


I would accept that but, as I said above, the types are defined in a
file that is not part of the library implementation.

> Why don't you ask your development supervisor where they get those
> types? They will probably be able to explain why 'std::' is used
> there.


I have. They have an external file stdint.h defining these types.
It is not part of any of the compilers we use. It is hand made to
imitate the types defined for C99. Some definitions init it even
collide with those in types.h in gcc-3.3. I have brought up this point
repeatedly with the leads to no avail. For my own satisfaction I'd
like to get to the bottom of this, which is why I posted.
 
Reply With Quote
 
Victor Bazarov
Guest
Posts: n/a
 
      12-05-2003
"Andy Skypeck" <(E-Mail Removed)> wrote...
> "Victor Bazarov" <(E-Mail Removed)> wrote in message

news:<KuJzb.418968$HS4.3341510@attbi_s01>...
> > "Andy Skypeck" <(E-Mail Removed)> wrote...
> > > I am looking for some validation against a dubious coding practice
> > > that prevails where I work.

> >
> > Take my word for it: it's better to go with the flow than against
> > it. Whether your coding practice is dubious or not, it's accepted
> > in the organisation, and you should do the same if you want to keep
> > your job.

>
> The organisation touts itself as a quality driven "six sigma"
> environment. It seeks to write portable, robust, correct C++
> code. Questioning what to me seems to be an incorrect
> practice is very much in the spirit of the organisation.
> Correctness should win out.
>
> > > C types defined in types.h (Linux) or
> > > stdint.h (Windows, C99?) are used as if they belong to the C++
> > > standard namespace.
> > >
> > > std::uint8_t instead of uint8_t
> > > std::uint32_t instead of uint32_t
> > > ...
> > >
> > > I don't think the use of std:: is correct. Nowhere are these types
> > > explicitly added to the std namespace.

> >
> > What do you mean by that?
> >
> > > In fact GCC 3.3 fails on them.

> > So? How is that proof of anything?

>
> The release notes for GCC-3.3 discuss types included in std::
>
> > > Neither are they among the types defined in the C++ standard language
> > > support files listed on page 433 in Stroustrup (2nd Ed.)
> > >
> > > std::size_t
> > > std:trdiff_t
> > > std::NULL
> > >
> > > defined in <cstddef> are ok. I am wrong about this?

> >
> > NULL is a macro, it cannot be defined in a namespace. The Standard
> > says (17.4.1.1):

>
> I stand corrected on NULL.
>
> > Now, there is a subclause that says "It is undefined for a C++
> > program to add declarations or definitions to namespace std [...]"
> > but it could be argued that types you listed (uint8_t, etc.) are
> > part of the library implementation and as such belong to std...

>
> I would accept that but, as I said above, the types are defined in a
> file that is not part of the library implementation.
>
> > Why don't you ask your development supervisor where they get those
> > types? They will probably be able to explain why 'std::' is used
> > there.

>
> I have. They have an external file stdint.h defining these types.
> It is not part of any of the compilers we use. It is hand made to
> imitate the types defined for C99. Some definitions init it even
> collide with those in types.h in gcc-3.3. I have brought up this point
> repeatedly with the leads to no avail. For my own satisfaction I'd
> like to get to the bottom of this, which is why I posted.


Andy,

If you're trying to figure out why such thing has been done, you need
to keep talking to your colleagues and leads. There must not be "to no
avail" there. You are simply not supposed to give up. They are YOUR
colleagues, you're supposed to work TOGETHER, not against each other.

If you're looking for a justification to pick up a fight with them,
it is quite possible that you'll lose. They will tell you "we needed
those C99 types, since they are likely to be included in C++0x, so we
put them where our compiler can find them, and we put them in the 'std'
namespace because that's where they'll end up when added to C++0x".
The header <stdint.h> is standard in C99 and contains the "exact-width
integer types". A conflict with a GCC's non-standard header <types.h>
does NOT matter and has to be dealt with in a routine manner, not argued
about in public.

Just MHO.

Victor


 
Reply With Quote
 
 
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Re: __STDC_IEC_559__ (defined or !defined ?) Keith Thompson C Programming 0 08-17-2010 04:36 PM
User-defined exception: "global name 'TestRunError' is not defined" jmike@alum.mit.edu Python 1 07-10-2008 12:37 PM
defined? for recursive function call v/s defined? for function call stack Alok Ruby 3 04-13-2006 11:53 AM
Using parenthesis with defined (#if defined(...)) Angel Tsankov C++ 1 04-05-2006 10:00 PM
#if (defined(__STDC__) && !defined(NO_PROTOTYPE)) || defined(__cplusplus) Oodini C Programming 1 09-27-2005 07:58 PM



Advertisments