Re: [Boost-users] [Boost][mpl] vector_c boolean operations

"Noel Belcourt" writes:

Let me see if I understand this.

So if I want to perform an element-wise mpl::or operation of two sequences (r, p1) and then test the resulting sequence for equivalence to the input sequence, something like this should work since as you observe below, mpl::equal will compare two sequences and yield a scalar boolean.

BOOST_STATIC_ASSERT(( equal< r , transform >::type

...

::type::value ));

Yes. BOOST_MPL_ASSERT((equal >::type>)); would be nicer and give better messages. And other things might be much more efficient, e.g. BOOST_MPL_ASSERT(( equal_to< find< zip_view , not_equal_to,or_,second<_> > >::type , end >::type > ))

...

Second, you seem to be trying to use the equal algorithm, which operates on sequences, on the results of some invocation of mpl::or_, which does not return a sequence but a scalar bool-valued MPL integral constant.

True, I was confused about this point. So I'll use transform to generate a sequence representing the element-wise binary operation and then use equal.

Great; good luck! -- Dave Abrahams Boost Consulting www.boost-consulting.com