Hi,

When building ACE/TAO I get the warning: Warning 6: value of expression is not used

In ACE/TAO we use a macro ACE_UNUSED_ARG for arguments which are there, but
not used under certain conditions. The macro is defined as
# define ACE_UNUSED_ARG(a) do {/* null */} while (&a == 0)
or
# define ACE_UNUSED_ARG(a) (a)

But both don't suppress the warning with DMC? Anyone an idea how to get rid of warning 6, with such a macro, we don't want do disable it completely.

Johnny

"Johnny Willemsen" <jwillemsen@remedy.nl> wrote in news:ciuli7$1d7s$1@digitaldaemon.com:

> Anyone an idea how to
> get rid of warning 6, with such a macro, we don't want do disable it
> completely.

In wxWidgets we have:

    #define WXUNUSED(identifier)

    #ifdef __BORLANDC__
    #   define wxUnusedVar(identifier) identifier
    #else
        template <class T>
            inline void wxUnusedVar(const T& WXUNUSED(t)) { }
    #endif

and then write code which afaik works with all c++ compilers we support (including DMC):

    wxUnusedVar(some_variable);

ABX

Hi,

Thanks for this, I have added such a construct also to ACE. I only observed that the template way of doing this, increases the size of the app a little, the do/while solution is optimized out by the compiler, the template probably not.

Johnny

"W³odzimierz Skiba" <abx@abx.art.pl> wrote in message news:ciurr4$1j0m$1@digitaldaemon.com...
> "Johnny Willemsen" <jwillemsen@remedy.nl> wrote in news:ciuli7$1d7s$1@digitaldaemon.com:
>
>> Anyone an idea how to
>> get rid of warning 6, with such a macro, we don't want do disable it
>> completely.
>
> In wxWidgets we have:
>
>    #define WXUNUSED(identifier)
>
>    #ifdef __BORLANDC__
>    #   define wxUnusedVar(identifier) identifier
>    #else
>        template <class T>
>            inline void wxUnusedVar(const T& WXUNUSED(t)) { }
>    #endif
>
> and then write code which afaik works with all c++ compilers we support
> (including DMC):
>
>    wxUnusedVar(some_variable);
>
> ABX

"Johnny Willemsen" <jwillemsen@remedy.nl> wrote in message news:ciuli7$1d7s$1@digitaldaemon.com...
> Hi,
>
> When building ACE/TAO I get the warning: Warning 6: value of expression is not used
>
> In ACE/TAO we use a macro ACE_UNUSED_ARG for arguments which are there,
but
> not used under certain conditions. The macro is defined as
> # define ACE_UNUSED_ARG(a) do {/* null */} while (&a == 0)
> or
> # define ACE_UNUSED_ARG(a) (a)
>
> But both don't suppress the warning with DMC? Anyone an idea how to get
rid
> of warning 6, with such a macro, we don't want do disable it completely.

-w6

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