boost/numeric/interval/rounding.hpp
/* Boost interval/rounding.hpp template implementation file
*
* Copyright 2002-2003 Herv� Br�nnimann, Guillaume Melquiond, Sylvain Pion
*
* Distributed under the Boost Software License, Version 1.0.
* (See accompanying file LICENSE_1_0.txt or
* copy at http://www.boost.org/LICENSE_1_0.txt)
*/
#ifndef BOOST_NUMERIC_INTERVAL_ROUNDING_HPP
#define BOOST_NUMERIC_INTERVAL_ROUNDING_HPP
namespace boost {
namespace numeric {
namespace interval_lib {
/*
* Default rounding_control class (does nothing)
*/
template<class T>
struct rounding_control
{
typedef int rounding_mode;
static void get_rounding_mode(rounding_mode&) {}
static void set_rounding_mode(rounding_mode) {}
static void upward() {}
static void downward() {}
static void to_nearest() {}
static const T& to_int(const T& x) { return x; }
static const T& force_rounding(const T& x) { return x; }
};
/*
* A few rounding control classes (exact/std/opp: see documentation)
* rounded_arith_* control the rounding of the arithmetic operators
* rounded_transc_* control the rounding of the transcendental functions
*/
template<class T, class Rounding = rounding_control<T> >
struct rounded_arith_exact;
template<class T, class Rounding = rounding_control<T> >
struct rounded_arith_std;
template<class T, class Rounding = rounding_control<T> >
struct rounded_arith_opp;
template<class T, class Rounding>
struct rounded_transc_dummy;
template<class T, class Rounding = rounded_arith_exact<T> >
struct rounded_transc_exact;
template<class T, class Rounding = rounded_arith_std<T> >
struct rounded_transc_std;
template<class T, class Rounding = rounded_arith_opp<T> >
struct rounded_transc_opp;
/*
* State-saving classes: allow to set and reset rounding control
*/
namespace detail {
template<class Rounding>
struct save_state_unprotected: Rounding
{
typedef save_state_unprotected<Rounding> unprotected_rounding;
};
} // namespace detail
template<class Rounding>
struct save_state: Rounding
{
typename Rounding::rounding_mode mode;
save_state() {
this->get_rounding_mode(mode);
this->init();
}
~save_state() { this->set_rounding_mode(mode); }
typedef detail::save_state_unprotected<Rounding> unprotected_rounding;
};
template<class Rounding>
struct save_state_nothing: Rounding
{
typedef save_state_nothing<Rounding> unprotected_rounding;
};
template<class T>
struct rounded_math: save_state_nothing<rounded_arith_exact<T> >
{};
} // namespace interval_lib
} // namespace numeric
} // namespace boost
#endif // BOOST_NUMERIC_INTERVAL_ROUNDING_HPP