boost/numeric/interval/checking.hpp
/* Boost interval/checking.hpp template implementation file
*
* Copyright Herv� Br�nnimann, Guillaume Melquiond, Sylvain Pion 2002
* Permission to use, copy, modify, sell, and distribute this software
* is hereby granted without fee provided that the above copyright notice
* appears in all copies and that both that copyright notice and this
* permission notice appear in supporting documentation,
*
* None of the above authors nor Polytechnic University make any
* representation about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
* $Id: checking.hpp,v 1.5 2003/06/01 05:50:53 gmelquio Exp $
*/
#ifndef BOOST_NUMERIC_INTERVAL_CHECKING_HPP
#define BOOST_NUMERIC_INTERVAL_CHECKING_HPP
#include <stdexcept>
#include <cassert>
#include <boost/limits.hpp>
namespace boost {
namespace numeric {
namespace interval_lib {
struct exception_create_empty
{
void operator()()
{
throw std::runtime_error("boost::interval: empty interval created");
}
};
struct exception_invalid_number
{
void operator()()
{
throw std::invalid_argument("boost::interval: invalid number");
}
};
template<class T>
struct checking_base
{
static T inf()
{
assert(std::numeric_limits<T>::has_infinity);
return std::numeric_limits<T>::infinity();
}
static T nan()
{
assert(std::numeric_limits<T>::has_quiet_NaN);
return std::numeric_limits<T>::quiet_NaN();
}
static bool is_nan(const T& x)
{
return std::numeric_limits<T>::has_quiet_NaN && (x != x);
}
static T empty_lower()
{
return (std::numeric_limits<T>::has_quiet_NaN ?
std::numeric_limits<T>::quiet_NaN() : static_cast<T>(1));
}
static T empty_upper()
{
return (std::numeric_limits<T>::has_quiet_NaN ?
std::numeric_limits<T>::quiet_NaN() : static_cast<T>(0));
}
static bool is_empty(const T& l, const T& u)
{
return !(l <= u); // safety for partial orders
}
};
template<class T, class Checking = checking_base<T>,
class Exception = exception_create_empty>
struct checking_no_empty: Checking
{
static T nan()
{
assert(false);
return Checking::nan();
}
static T empty_lower()
{
Exception()();
return Checking::empty_lower();
}
static T empty_upper()
{
Exception()();
return Checking::empty_upper();
}
static bool is_empty(const T&, const T&)
{
return false;
}
};
template<class T, class Checking = checking_base<T> >
struct checking_no_nan: Checking
{
static bool is_nan(const T&)
{
return false;
}
};
template<class T, class Checking = checking_base<T>,
class Exception = exception_invalid_number>
struct checking_catch_nan: Checking
{
static bool is_nan(const T& x)
{
if (Checking::is_nan(x)) Exception()();
return false;
}
};
template<class T>
struct checking_strict:
checking_no_nan<T, checking_no_empty<T> >
{};
namespace detail {
template <class T> inline bool is_nan(const T& x) { return x != x; }
} // namespace detail
} // namespace interval_lib
} // namespace numeric
} // namespace boost
#endif // BOOST_NUMERIC_INTERVAL_CHECKING_HPP