Re: C / C++ Language Standards

[Ingo Krabbe <ikrabbe dot ask at web dot de>]

Am Donnerstag, 27. Juli 2006 23:55 schrieb João Lopes:
> Hi,
>
> I am trying to understand what "versions" of C and C++ exists, and what
> are supported by GCC.
>
>     *Language Standards Supported by GCC*
>     http://gcc.gnu.org/onlinedocs/gcc-4.1.0/gcc/Standards.html#Standards
>     *Options Controlling C Dialect*
>     http://gcc.gnu.org/onlinedocs/gcc-4.1.0/gcc/C-Dialect-Options.html
>
>
> For example, i can say "At project X we will use PHP 5.1, or JAVA 1.5",
> but if i use C++ what can i say ?

Saying you use JAVA 1.5 means that you don't use a standard but sun's java 
machine at version 1.5.  The same for PHP, since you use a php installation 
of the 5.1 release from the php.net group.

Both aren't standardized by some industrie standard commitee but are as-is 
standards from a production and management group.

When you use a ANSI C Compiler, as GCC is as described at the first link, you 
can say you implement your project X with (ANSI X3.159-1989) which is the 
correct reference to the ANSI standard document also known as 'c89' (which 
referes to the UNIX System Command as described here:
http://www.opengroup.org/onlinepubs/007908799/xcu/c89.html  ).

Later ISO took over the standardization of C, taken C89 and moved that to C90, 
which is a shortcut for ISO/IEC 9899:1990 (see the arguments to the -std 
option with gcc).

Of course if you don't want to use the standard specifications you can do the 
same as you did with java and php telling:

We make project X with PHP5.1, Java 1.5 and GCC 4.

But you can also say:

We make project X with PHP5.1, Java 1.5 and any ISO/IEC 9899:1990 conforming C 
Compiler (i.e. GCC 3,4).

See also the wikipedia articles to the C and C++ languages, describing also 
several compilers at the market and the standards that apply to the 
languages.

C++03 isn't currently implemented by any compiler, as far as I know, since the 
standard specification is in development itself.

See also:

http://www.research.att.com/~bs/C++.html






> Google tells me about two C++ Standards ( C++98 / C++03 ) / /and two C
> Standards ( C89 / C99 ),  so i can say this :
>
> "I will use C++ ISO98 on project X, by using GCC with *-std=**c++98*"
> "I will use C     ISO99 on project X, by using GCC with  *-std=**c99*"
>
> Thanks,
> João Lopes