Re: [boost] [Accumulators + Signals2] Compilation error with GCC when both are used

Subject: Re: [boost] [Accumulators + Signals2] Compilation error with GCC when both are used
From: sguazt (marco.guazzone_at_[hidden])
Date: 2011-06-09 09:29:58

On Thu, Jun 9, 2011 at 3:20 PM, Frank Mori Hess <frank.hess_at_[hidden]> wrote:
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> On Thursday, June 09, 2011, sguazt wrote:
>> I get the following errors:
>> --- [error] ---
>> In file included from ./boost-trunk/boost/signals2.hpp:20:0,
>>                  from boost_signals2_accumulators.cpp:4:
>> ./boost-trunk/boost/signals2/signal_type.hpp:29:2: error: #error This
>> header requires BOOST_PARAMETER_MAX_ARITY to be defined as 7 or
>> greater prior to including Boost.Parameter headers
>
> BOOST_PARAMETER_MAX_ARITY is a user-definable macro used by Boost.Parameter.
> boost/signals2/signal_type.hpp needs it to be at least 7, but will only set
> it to 7 if it hasn't already been defined by the user or by an earlier
> include of the Boost.Parameter headers (which is probably done by the
> Accumulators library).  So you need to either define
> BOOST_PARAMETER_MAX_ARITY to 7 or more (preferably as a compiler option so
> it is done before any includes), or take some care to either not include
> signal_type.hpp or make sure it gets included before
> boost/parameter/config.hpp (which will default define the macro to 5).
>

Gordon and Frank,
Thank you very much for your quick reply.
Indeed, setting BOOST_PARAMETER_MAX_ARITY to 7 seems to fix.
Hope this "design issue" (?!?) will be fixed later... From the macro
name, it seems something related to the emulation of C++0x variable
template parameters.

Thank you very much!

Best,

-- Marco