Re: [Boost-users] [fusion] C arrays in fusion::vector

Subject: Re: [Boost-users] [fusion] C arrays in fusion::vector
From: Christopher Schmidt (mr.chr.schmidt_at_[hidden])
Date: 2009-10-10 18:22:19

Jean-Louis Leroy schrieb:
> msvc9+fusion 1.40 reject this:
> 
>   fusion::vector<int, char[20]> v;
> 
> 1>C:\Users\JLL\Documents\Visual Studio 
> 2008\Projects\boost_1_40_0\boost/fusion/container/vector/detail/vector_n.hpp(43) 
> : error C2440: '<function-style-cast>' : cannot convert from 'int' to 
> 'char [20]'
> 1>        There are no conversions to array types, although there are 
> conversions to references or pointers to arrays
> 1>        C:\Users\JLL\Documents\Visual Studio 
> 2008\Projects\boost_1_40_0\boost/fusion/container/vector/detail/vector_n.hpp(42) 
> : while compiling class template member function 
> 'boost::fusion::vector_data2<Derived,T0,T1>::vector_data2(void)'
> 1>        with
> 1>        [
> 1>            Derived=boost::fusion::vector2<int,char [20]>,
> 1>            T0=int,
> 1>            T1=char [20]
> 1>        ]
> 
> Am I doing something wrong ?
> 
> Anyway I can wrap the C array in a class (template)...
> 
> Thanks,
> J-L

That's because fusion containers internally initialize their elements in 
the default constructor via e0(T0()),...eN-1(TN-1()).
I consider this to be a bug, fusion containers should initialize their 
elements analogue to std::pair and std::tuple simply via m0(),...mN-1().

-Christopher