• "Johnny Willemsen" <jwillemsen remedy.nl> Sep 23 2004
• "W³odzimierz Skiba" <abx abx.art.pl> Sep 23 2004
• "Johnny Willemsen" <jwillemsen remedy.nl> Sep 24 2004
• "Walter" <newshound digitalmars.com> Sep 30 2004

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,


 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


 of warning 6, with such a macro, we don't want do disable it completely.


-w6

see www.digitalmars.com/ctg/sc.html#dashw