sl@0: /* Boost interval/checking.hpp template implementation file
sl@0:  *
sl@0:  * Copyright 2002 Hervé Brönnimann, Guillaume Melquiond, Sylvain Pion
sl@0:  *
sl@0:  * Distributed under the Boost Software License, Version 1.0.
sl@0:  * (See accompanying file LICENSE_1_0.txt or
sl@0:  * copy at http://www.boost.org/LICENSE_1_0.txt)
sl@0:  */
sl@0: 
sl@0: #ifndef BOOST_NUMERIC_INTERVAL_CHECKING_HPP
sl@0: #define BOOST_NUMERIC_INTERVAL_CHECKING_HPP
sl@0: 
sl@0: #include <stdexcept>
sl@0: #include <string>
sl@0: #include <cassert>
sl@0: #include <boost/limits.hpp>
sl@0: 
sl@0: namespace boost {
sl@0: namespace numeric {
sl@0: namespace interval_lib {
sl@0: 
sl@0: struct exception_create_empty
sl@0: {
sl@0:   void operator()()
sl@0:   {
sl@0:     throw std::runtime_error("boost::interval: empty interval created");
sl@0:   }
sl@0: };
sl@0: 
sl@0: struct exception_invalid_number
sl@0: {
sl@0:   void operator()()
sl@0:   {
sl@0:     throw std::invalid_argument("boost::interval: invalid number");
sl@0:   }
sl@0: };
sl@0: 
sl@0: template<class T>
sl@0: struct checking_base
sl@0: {
sl@0:   static T pos_inf()
sl@0:   {
sl@0:     assert(std::numeric_limits<T>::has_infinity);
sl@0:     return std::numeric_limits<T>::infinity();
sl@0:   }
sl@0:   static T neg_inf()
sl@0:   {
sl@0:     assert(std::numeric_limits<T>::has_infinity);
sl@0:     return -std::numeric_limits<T>::infinity();
sl@0:   }
sl@0:   static T nan()
sl@0:   {
sl@0:     assert(std::numeric_limits<T>::has_quiet_NaN);
sl@0:     return std::numeric_limits<T>::quiet_NaN();
sl@0:   }
sl@0:   static bool is_nan(const T& x)
sl@0:   {
sl@0:     return std::numeric_limits<T>::has_quiet_NaN && (x != x);
sl@0:   }
sl@0:   static T empty_lower()
sl@0:   {
sl@0:     return (std::numeric_limits<T>::has_quiet_NaN ?
sl@0:             std::numeric_limits<T>::quiet_NaN() : static_cast<T>(1));
sl@0:   }
sl@0:   static T empty_upper()
sl@0:   {
sl@0:     return (std::numeric_limits<T>::has_quiet_NaN ?
sl@0:             std::numeric_limits<T>::quiet_NaN() : static_cast<T>(0));
sl@0:   }
sl@0:   static bool is_empty(const T& l, const T& u)
sl@0:   {
sl@0:     return !(l <= u); // safety for partial orders
sl@0:   }
sl@0: };
sl@0: 
sl@0: template<class T, class Checking = checking_base<T>,
sl@0:          class Exception = exception_create_empty>
sl@0: struct checking_no_empty: Checking
sl@0: {
sl@0:   static T nan()
sl@0:   {
sl@0:     assert(false);
sl@0:     return Checking::nan();
sl@0:   }
sl@0:   static T empty_lower()
sl@0:   {
sl@0:     Exception()();
sl@0:     return Checking::empty_lower();
sl@0:   }
sl@0:   static T empty_upper()
sl@0:   {
sl@0:     Exception()();
sl@0:     return Checking::empty_upper();
sl@0:   }
sl@0:   static bool is_empty(const T&, const T&)
sl@0:   {
sl@0:     return false;
sl@0:   }
sl@0: };
sl@0: 
sl@0: template<class T, class Checking = checking_base<T> >
sl@0: struct checking_no_nan: Checking
sl@0: {
sl@0:   static bool is_nan(const T&)
sl@0:   {
sl@0:     return false;
sl@0:   }
sl@0: };
sl@0: 
sl@0: template<class T, class Checking = checking_base<T>,
sl@0:          class Exception = exception_invalid_number>
sl@0: struct checking_catch_nan: Checking
sl@0: {
sl@0:   static bool is_nan(const T& x)
sl@0:   {
sl@0:     if (Checking::is_nan(x)) Exception()();
sl@0:     return false;
sl@0:   }
sl@0: };
sl@0: 
sl@0: template<class T>
sl@0: struct checking_strict:
sl@0:   checking_no_nan<T, checking_no_empty<T> >
sl@0: {};
sl@0: 
sl@0: } // namespace interval_lib
sl@0: } // namespace numeric
sl@0: } // namespace boost
sl@0: 
sl@0: #endif // BOOST_NUMERIC_INTERVAL_CHECKING_HPP