[boost] is_const type trats implementation

From: Gennadiy Rozental (rogeeff_at_[hidden])
Date: 2002-07-26 17:25:31

is_const type trats implementation for compilers without partal
specialization using helper template is_const_impl/is_const_helper like
this:

template <bool is_ref = true, bool array>
struct is_const_helper
    : ::boost::type_traits::false_result
{
};

Sunpro 6.1 does not like default template parameter since it is not the last
parameter. Could we fix it somehow?

Gennadiy.