Calibration/facilities/include/facilities/Utility.h

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// $Header: /bes/bes/BossCvs/Calibration/facilities/facilities/Utility.h,v 1.1.1.1 2005/10/17
// 06:11:40 maqm Exp $ author: Sawyer Gillespie
 
#ifndef _H_FACILITES_UTILITY
#  define _H_FACILITIES_UTILITY
 
#  include <algorithm>
#  include <utility>
#  include <vector>
 
// utility functions for use with iterators -
 
// NOTE: In STL form, these functions could be encapsulated into iterators
//  themselves. However the gcc compiler does not necessarily support the
//  iterator class (?). It is
//  therefore more simple to create these functions
//  (it also requires less code, but might not be as useful down the road).
 
template <class FwdIt, class UniPred, class BinPred>
inline std::pair<FwdIt, FwdIt> adjacent_find_if( const FwdIt& first, const FwdIt& last,
                                                 UniPred if_pred, BinPred adj_pred ) {
  FwdIt i = std::find_if( first, last, if_pred );
  FwdIt j = i;
  if ( i != last ) i = std::find_if( ++i, last, if_pred );
  while ( i != last )
  {
    if ( adj_pred( ( *j ), ( *i ) ) ) return std::make_pair( j, i );
    j = i++;
    while ( !( if_pred( *i ) ) && ( i != last ) ) ++i;
  }
  return std::make_pair( last, last );
}
 
template <class FwdIt, class UniPred, class BinPred>
inline std::vector<FwdIt> adjacent_find_multiple( const FwdIt& first, const FwdIt& last,
                                                  UniPred if_pred, BinPred adj_pred,
                                                  unsigned N = 2 )
 
// FwdIt class is a forward iterator class into a container (must support ++ operator)
// BinPred is a binary predicate function which returns bool (note that there are two separate
//  comparison functions: one for the individual element adjacency, and another for group
//  adjacency (that is there are two levels of adjacency here.)
{
  std::vector<FwdIt>      itvec;
  std::pair<FwdIt, FwdIt> adjpr1 = adjacent_find_if( first, last, if_pred, adj_pred );
  if ( adjpr1.second == last ) return itvec;
 
  itvec.push_back( adjpr1.first );
  itvec.push_back( adjpr1.second );
  std::pair<FwdIt, FwdIt> adjpr2;
 
  while ( ( itvec.size() < N ) && ( adjpr1.second != last ) )
  {
    adjpr2 = adjacent_find_if( adjpr1.second, last, if_pred, adj_pred );
    if ( adjpr2.second == last ) return std::vector<FwdIt>();
    if ( adj_pred( ( *adjpr1.second ), ( *adjpr2.second ) ) ) itvec.push_back( adjpr2.second );
    else
    {
      itvec.clear();
      itvec.push_back( adjpr2.first );
      itvec.push_back( adjpr2.second );
    }
    adjpr1.second = adjpr2.second;
  }
  return itvec;
}
#endif