[libiberty] Add ARG_UNUSED as a C++-friendly replacement for ATTRIBUTE_UNUSED

[Jason Merrill]

On Tue, 13 Jul 2004 10:15:47 +0200, Bernardo Innocenti <bernie@develer.com> wrote:

> Richard Henderson wrote:
>> On Tue, Jul 13, 2004 at 09:50:36AM +0200, Bernardo Innocenti wrote:
>> 
>>>define ARG_UNUSED(T,N) to "T N").
>> 
>> 
>> If we do this, I'd prefer
>> 
>> 	T ARG_UNUSED(N)
>> 
>> #ifdef __cplusplus
>> # define ARG_UNUSED(N)
>> #elif somegccversion
>> # define ARG_UNUSED(N)	N ATTRIBUTE_UNUSED
>> #else
>> # define ARG_UNUSED(N)	N
>> #endif
>
> This wouldn't allow us to support g++ < 3.4:
>
>  # define ARG_UNUSED(T,N)   ATTRIBUTE_UNUSED T N

Huh?  rth's definition above supports all C++ compilers just fine.

Jason