// Boost.Units - A C++ library for zero-overhead dimensional analysis and // unit/quantity manipulation and conversion // // Copyright (C) 2003-2008 Matthias Christian Schabel // Copyright (C) 2008 Steven Watanabe // // 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_UNITS_POW_HPP #define BOOST_UNITS_POW_HPP #include <boost/type_traits/is_integral.hpp> #include <boost/units/operators.hpp> #include <boost/units/static_rational.hpp> #include <boost/units/detail/static_rational_power.hpp> /// \file /// \brief Raise values to exponents known at compile-time. namespace boost { namespace units { /// raise a value to a @c static_rational power. template<class Rat,class Y> BOOST_CONSTEXPR inline typename power_typeof_helper<Y,Rat>::type pow(const Y& x) { return power_typeof_helper<Y,Rat>::value(x); } /// raise a value to an integer power. template<long N,class Y> BOOST_CONSTEXPR inline typename power_typeof_helper<Y,static_rational<N> >::type pow(const Y& x) { return power_typeof_helper<Y,static_rational<N> >::value(x); } #ifndef BOOST_UNITS_DOXYGEN /// raise @c T to a @c static_rational power. template<class T, long N,long D> struct power_typeof_helper<T, static_rational<N,D> > { typedef typename mpl::if_<boost::is_integral<T>, double, T>::type internal_type; typedef detail::static_rational_power_impl<static_rational<N, D>, internal_type> impl; typedef typename impl::type type; static BOOST_CONSTEXPR type value(const T& x) { return impl::call(x); } }; /// raise @c float to a @c static_rational power. template<long N,long D> struct power_typeof_helper<float, static_rational<N,D> > { // N.B. pathscale doesn't accept inheritance for some reason. typedef power_typeof_helper<double, static_rational<N,D> > base; typedef typename base::type type; static BOOST_CONSTEXPR type value(const double& x) { return base::value(x); } }; #endif /// take the @c static_rational root of a value. template<class Rat,class Y> BOOST_CONSTEXPR typename root_typeof_helper<Y,Rat>::type root(const Y& x) { return root_typeof_helper<Y,Rat>::value(x); } /// take the integer root of a value. template<long N,class Y> BOOST_CONSTEXPR typename root_typeof_helper<Y,static_rational<N> >::type root(const Y& x) { return root_typeof_helper<Y,static_rational<N> >::value(x); } #ifndef BOOST_UNITS_DOXYGEN /// take @c static_rational root of an @c T template<class T, long N,long D> struct root_typeof_helper<T,static_rational<N,D> > { // N.B. pathscale doesn't accept inheritance for some reason. typedef power_typeof_helper<T, static_rational<D,N> > base; typedef typename base::type type; static BOOST_CONSTEXPR type value(const T& x) { return(base::value(x)); } }; #endif } // namespace units } // namespace boost #endif // BOOST_UNITS_STATIC_RATIONAL_HPP