min_positive_element.h

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//
//
/*
    Copyright (C) 2002- 2007, Hammersmith Imanet Ltd
    This file is part of STIR.
 
    SPDX-License-Identifier: Apache-2.0
 
    See STIR/LICENSE.txt for details
*/
 
#ifndef __stir_min_positive_element_h_
#define __stir_min_positive_element_h_

 
#include "stir/common.h"
#include <iostream>
START_NAMESPACE_STIR


template <typename ForwardIter_t>
ForwardIter_t
min_positive_element(ForwardIter_t start, ForwardIter_t end)
{
  // go and look for the first (strictly) positive number
  while (start != end && *start <= 0)
    ++start;
  if (start == end)
    return end;
 
  // now look through the rest for a smaller positive number
  ForwardIter_t result = start;
  while (++start != end)
    if (!(*start <= 0) && *start < *result)
      result = start;
 
  return result;
}
 
END_NAMESPACE_STIR
#endif