namespace boost {
  namespace itl {
    template<typename DomainT , 
             ITL_COMPARE Compare = ITL_COMPARE_INSTANCE(std::less, DomainT), 
             template< class, ITL_COMPARE >class Interval = itl::interval, 
             ITL_ALLOC Alloc = std::allocator> 
      class interval_set;

    template<class DomainT , ITL_COMPARE Compare, 
             template< class, ITL_COMPARE >class Interval, ITL_ALLOC Alloc> 
      struct is_set<itl::interval_set< DomainT, Compare, Interval, Alloc >>;
    template<class DomainT , ITL_COMPARE Compare, 
             template< class, ITL_COMPARE >class Interval, ITL_ALLOC Alloc> 
      struct is_interval_container<itl::interval_set< DomainT, Compare, Interval, Alloc >>;
    template<class DomainT , ITL_COMPARE Compare, 
             template< class, ITL_COMPARE >class Interval, ITL_ALLOC Alloc> 
      struct type_to_string<itl::interval_set< DomainT, Compare, Interval, Alloc >>;
    template<class DomainT , ITL_COMPARE Compare, 
             template< class, ITL_COMPARE >class Interval, ITL_ALLOC Alloc> 
      bool is_element_equal(const interval_set< DomainT, Compare, Interval, Alloc > & lhs, 
                            const interval_set< DomainT, Compare, Interval, Alloc > & rhs);
  }
}