Concept definition

template<class P>
concept PBeFS_di_unipi_it::BranchAndBound =  requires( const P & p , unsigned i ) {
 typename P::node_type;
 requires std::copyable< typename P::node_type >;
 requires BBValue< bb_value_t< P > >;
 { P::sense } -> std::convertible_to< Sense >;
 { p.root() } -> std::convertible_to< typename P::node_type >;
 } && ( BBEvaluator< const P , typename P::node_type , bb_value_t< P > > ||
        requires( const P & p , unsigned i ) {
         { p.make_worker( i ) }
          -> BBEvaluator< typename P::node_type , bb_value_t< P > >;
         } )

Detailed Description

a B&B problem

A type P is a BranchAndBound problem if it provides the copyable type node_type, the constant sense, the method root() giving the node of the whole set, optionally the type value_type of its values [see BBValue], double if it gives none, and either the methods evaluate( n ) and branch( n , sink ) of a BBEvaluator, which have to be safe to call concurrently in a parallel search, or make_worker( i ), which returns the BBEvaluator of the worker i (e.g., one with its own copy of a model and of a solver).

Optionally, P may give hash( n ), which the distributed search uses to send n to its owner, and estimate( n ), the estimate of the best feasible value under n that orders the nodes with Selection::best_estimate.