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

On Oct 1, 2005, at 6:57 PM, David Abrahams wrote:

"Noel Belcourt" writes:

...

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_MPL_ASSERT((equal >::type>));

One more observation about this, this code doesn't compile if r and p1 are a vector_c or a vector_c with CW 9.5 on Tiger 10.4.2. The compiler output is attached. For example, if r and p1 are declared as follows, the code will not compile. typedef vector_c r,p1; BOOST_MPL_ASSERT(( equal >::type>)); The problem seems to be that the sequence produced by invoking transform using a boolean binary function is a different type than vector_c. The fix is trivial. typedef vector_c r,p1; BOOST_MPL_ASSERT(( equal >::type, transform >::type>)); While clunky, this works, and also works if we declare r and p1 as vector_c. Just want to be sure that this is known and expected behavior?

BOOST_MPL_ASSERT(( equal_to< find< zip_view , not_equal_to,or_,second<_> >

...

::type , end >::type

))

I'll be sure to read up on zip_view and try this out. Thanks for your help. -- Noel