pairutil.h

/***************************************************************************
 *
 *   Copyright (C) 2006-2009 by Willem van Straten
 *   Licensed under the Academic Free License version 2.1
 *
 ***************************************************************************/
 
#include <utility>
#include <iostream>
 
namespace std
{
  template<typename T>
  class numeric_limits< pair<T,T> >
  {
    public:
    static const int digits10 = numeric_limits<T>::digits10;
  };
 
  template<class T, class U>
  ostream& operator << (ostream& os, pair<T,U> vals)
  {
    return os << vals.first << ":" << vals.second;
  }
 
  template<class T, class U>
  istream& operator >> (istream& is, pair<T,U>& vals)
  {
    bool bracketed = is.peek() == '(';
 
    if (bracketed)
      is.get();
 
    char separator = 0;
 
    is >> vals.first >> separator >> vals.second;
 
    if ( (bracketed && separator != ',') || (!bracketed && separator != ':') )
    {
      is.setstate (istream::failbit);
      return is;
    }
 
    if (bracketed)
    {
      if (is.peek() != ')')
        is.setstate (istream::failbit);
      else
        is.get();
    }
 
    return is;
  }
}
 
// Stretch min and max to normalized range
template<typename T>
void stretch (const std::pair<T,T>& norm, T& min, T& max)
{
  T diff = max - min;
  max = min + norm.second * diff;
  min = min + norm.first * diff;
}
 
// Stretch range to normalized range
template<typename T>
void stretch (const std::pair<T,T>& norm, std::pair<T,T>& range)
{
  stretch (norm, range.first, range.second);
}
 
template<typename T, typename U>
bool compair1 (const std::pair<T,U>& a, const std::pair<T,U>& b)
{
  return a.first < b.first;
}
 
template<typename T, typename U>
bool compair2 (const std::pair<T,U>& a, const std::pair<T,U>& b)
{
  return a.second < b.second;
}