Re: [Boost-users] [Boost.Intrusive] Intrusive doubly linked list does not compile on xlC11.1

19 Nov 2011

      On 11/18/2011 10:51 AM, Ion Gaztañaga wrote:
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El 18/11/2011 2:09, Ioannis Papadopoulos escribió:
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On 11/15/2011 07:15 PM, Ioannis Papadopoulos wrote:
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Hi,
I'm trying to compile the intrusive doubly linked list example from
http://www.boost.org/doc/libs/1_47_0/doc/html/intrusive/list.html#intrusive....
using xlC11.1 on AIX/Power5+ and I am getting the following error:
Is xlC standard conforming enough? I don't access to that compiler so I
don't test it with that toolset.
Ion
xlC 11.1 is quite good and till now I haven't encountered major issues. 
I'm willing to go through the code and fix intrusive for xlC, provided 
that I get some guidance.

For starters, the is_convertible is invoking undefined behavior. xlC 
rightfully warns against passing a non-POD through ellipsis (only PODs 
are allowed there, otherwise it is considered undefined behavior:

"/scratch/ipapado/usr/include/boost/intrusive/detail/mpl.hpp", line 
70.45: 1540-2924 (W) Cannot pass an argument of non-POD class type 
"boost::intrusive::detail::is_convertibleboost::intrusive::none,boost::intrusive::none,boost::intrusive::none,&MyClass::member_hook_> 
*,boost::intrusive::detail::default_hook_tag *>::false_t" through ellipsis.

Changing it to

template 
class is_convertible
{
    typedef char true_t;
    /**/ struct /**/ false_t { char dummy[2]; };
    static true_t dispatch( /**/ U* /**/ );
    static false_t dispatch(...);
    public:
    static const bool value = sizeof(dispatch(static_cast(0))) == 
sizeof(true_t);
};

or using the one provided in type_traits, resolves the warnings. Still 
trying to figure out why the error with the conversion exists though.