Re: Selecting a C++ standard

[Bob Friesenhahn]

On Sun, 28 Oct 2012, Roger Leigh wrote:
> > Testing for features is a problem separate from compiler mode setting.
>
> Yes, but we aren't really talking about testing strict standards
> conformance here.  We just want the compiler put in a *specific*
> mode.  If I want C11, I certainly won't find the C99 or C89
> fallbacks useful at all.  I want it to fail there and then.

This is making the grave assumption that all compilers support options 
to support multiple explicit language modes and that system headers 
follow suit.  Total failure is not usually acceptable behavior.

If the code was written for C89 then I am likely to want to continue 
compiling it for C89 if possible but also allow "best effort" if the 
compiler does not have a C89 mode.  If the code is updated to also 
work properly for C99, then C99 can be requested.

Those of us who updated C89 code to work with C99 compilers realize 
that it is not necessarily a trivial task (e.g. changes to aliasing 
rules).  C99 code can be written in a way that it will work with C89 
compilers, but C89-originated code may malfunction when compiled with 
C99 compilers.

Bob
--
Bob Friesenhahn
address@hidden, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/