text: /* -*- mode: c++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
  
  /*
   Copyright (C) 2004, 2005, 2006, 2007 StatPro Italia srl
  
   This file is part of QuantLib, a free-software/open-source library
   for financial quantitative analysts and developers - http://quantlib.org/
  
   QuantLib is free software: you can redistribute it and/or modify it
   under the terms of the QuantLib license.  You should have received a
   copy of the license along with this program; if not, please email
   <quantlib-dev@lists.sf.net>. The license is also available online at
   <http://quantlib.org/license.shtml>.
  
   This program is distributed in the hope that it will be useful, but WITHOUT
   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
   FOR A PARTICULAR PURPOSE.  See the license for more details.
  */
  
  #include <ql/math/comparison.hpp>
  #include <ql/termstructure.hpp>
  #include <utility>
  
  namespace QuantLib {
  
      TermStructure::TermStructure(DayCounter dc)
      : settlementDays_(Null<Natural>()), dayCounter_(std::move(dc)) {}
  
      TermStructure::TermStructure(const Date& referenceDate, Calendar cal, DayCounter dc)
      : calendar_(std::move(cal)), referenceDate_(referenceDate), settlementDays_(Null<Natural>()),
        dayCounter_(std::move(dc)) {}
  
      TermStructure::TermStructure(Natural settlementDays, Calendar cal, DayCounter dc)
      : moving_(true), updated_(false), calendar_(std::move(cal)), settlementDays_(settlementDays),
        dayCounter_(std::move(dc)) {
          registerWith(Settings::instance().evaluationDate());
      }
  
      const Date& TermStructure::referenceDate() const {
          if (!updated_) {
              Date today = Settings::instance().evaluationDate();
              referenceDate_ = calendar().advance(today, settlementDays(), Days);
              updated_ = true;
          }
          return referenceDate_;
      }
  
      void TermStructure::update() {
          if (moving_)
              updated_ = false;
          notifyObservers();
      }
  
      void TermStructure::checkRange(const Date& d,
                                     bool extrapolate) const {
          QL_REQUIRE(d >= referenceDate(),
                     "date (" << d << ") before reference date (" <<
                     referenceDate() << ")");
          QL_REQUIRE(extrapolate || allowsExtrapolation() || d <= maxDate(),
                     "date (" << d << ") is past max curve date ("
                              << maxDate() << ")");
      }
  
      void TermStructure::checkRange(Time t,
                                     bool extrapolate) const {
          QL_REQUIRE(t >= 0.0,
                     "negative time (" << t << ") given");
          QL_REQUIRE(extrapolate || allowsExtrapolation()
                     || t <= maxTime() || close_enough(t, maxTime()),
                     "time (" << t << ") is past max curve time ("
                              << maxTime() << ")");
      }
  
  }
  