Concept definition

template<class D>
concept PBeFS_di_unipi_it::OperatorDomain =  Domain< D > &&
 requires( const D & d , const typename D::state_type & s ,
           typename D::cost_type h , std::uint8_t op ) {
  d.for_each_successor( s , h , op , detail::op_sink<
                         typename D::state_type , typename D::cost_type >{} );
  }

Detailed Description

a Domain that knows the operator by which a state was generated

for_each_successor( s , h_s , op , f ) calls f( t , c , h_t , op_t ) for every successor t of s except the one that the inverse of op leads to, op being the operator that generated s (no_op at the root) and op_t < no_op the one that generates t. Since the inverse move costs as much as the move, going back to the parent never gives a cheaper path, and the searches skip it without looking it up [see Burns et al., SoCS 2012].