Hi, This code: #include <boost/mpl/vector.hpp> #include <boost/mpl/pop_front.hpp> #include <boost/mpl/assert.hpp> #include <boost/mpl/equal.hpp> using namespace boost; // Doc says: pop_front returns a vector typedef mpl::pop_front< mpl::vector<bool,char,int> >::type v; // Doc says: vectors have a type member equal to itself BOOST_MPL_ASSERT(( mpl::equal< v, v::type > )); fails to compile with GCC ( v::type is mpl::vector3<bool,char,int> ) and compiles fine with other compilers. Examples for false conclusions that could be easily drawn from the current documentation: "Oh great - I do not need mpl::identity when using v with mpl::eval_if" "Let's inherit from 'v::type' so I can save the '::type' later" "::type always gives the numbered form of my current sequence so I can use it with partial specialization" I got trapped by this in two different places (and I still hope not to be surpassingly stupid ;-). Shouldn't this behaviour be documented in some way ? Regards, Tobias