Re: [Boost-users] [fusion] .at<N>() template member in containers?

6 Oct 2010


      On Wed, Oct 6, 2010 at 12:09 PM, michi7x7  wrote:
...
Hi
...
Besides possible redundancy, why is that the fusion containers, for
example fusion::vector, doesn't have a template member function to
extract elements?
what do you mean? .at<>() is a template member function.
at_c<N>() is from Boost.Spirit and uses .at<>() internally (i guess).
it doesn't seem so:

    vector bfv;
    clog << bfv.at<0>() << endl; //ERROR
 error: ‘struct boost::fusion::vector’ has no member named ‘at’
...
Wouldn't it be more consistent with std::vector v, v[2] or v.at(2);
...
That's not possible, because the return-type has to be known during
compile-time. You can't do this with "normal" arguments.
presicely, I am asking for .at<N>() (I just noticed that boost::tuples have
.get<N>() member)

Thanks for the answer,
Alfredo

Re: [Boost-users] [fusion] .at<N>() template member in containers?

Alfredo Correa