Re: [boost] Warning from share_ptr

From: Paul A Bristow (pbristow_at_[hidden])
Date: 2007-01-15 09:28:49

>-----Original Message-----
>From: boost-bounces_at_[hidden] 
>[mailto:boost-bounces_at_[hidden]] On Behalf Of Peter Dimov
>Sent: 14 January 2007 16:08
>To: boost_at_[hidden]
>Subject: Re: [boost] Warning from share_ptr
>
>Paul A Bristow wrote:
>> I am getting an annoying warning when building boost_math.dll AND
>> generating Microsoft VS 8.0 'managed' code /clr:pure, even at warning
>> level 1.
>>
>> (clr code is needed because we are building a Windows .net form in C#
>> to demonstrate Math function and Statistics Distribution using John
>> Maddock's Math Toolkit in C++.  Aside - with a lot of annoying
>> wrapping, John has made this work).
>>
>> The message is:
>>
>> C4793 'vararg' : causes native code generation for function 'void
>> boost::detail::sp_enable_shared_from_this(const
>> boost::detail::shared_count &,...)'

>If you compile with /clr:pure, you presumably don't want 
>native functions in 
>your assembly, so the warning is legitimate (unless the 
>optimizer is smart 
>enough to see that the function is empty and not include it in the 
>assembly).

I don't want this native function - and I don't believe I am using it,
so I presume the optimizer isn't smart enough to see that...

This works OK for me:

#ifdef _MANAGED
// C4793) // 'vararg' : causes native code generation for function 'void boost::detail::sp_enable_shared_from_this(const
boost::detail::shared_count &,...)'
// Avoid using vararg ... with a dummy.

struct sp_any_pointer
{
    template<class T> sp_any_pointer( T* ) {}
};

inline void sp_enable_shared_from_this( shared_count const & /*pn*/, 
sp_any_pointer, sp_any_pointer )
{
}

#else // NOT managed.

#ifdef sgi
// Turn off: the last argument of the varargs function "sp_enable_shared_from_this" is unnamed
# pragma set woff 3506
#endif

inline void sp_enable_shared_from_this( shared_count const & /*pn*/, ... )
{
}

#ifdef sgi
# pragma reset woff 3506
#endif

#endif // _MANAGED

So this looks much better than quieting the warning.

I have presumed that SGI won't generate this warning if it manages to produce managed code (and defines _MANAGED macro)?

Many thanks.

Paul

---
Paul A Bristow
Prizet Farmhouse, Kendal, Cumbria UK LA8 8AB
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pbristow_at_[hidden]