Chris@16: // Boost.Units - A C++ library for zero-overhead dimensional analysis and 
Chris@16: // unit/quantity manipulation and conversion
Chris@16: //
Chris@16: // Copyright (C) 2003-2008 Matthias Christian Schabel
Chris@16: // Copyright (C) 2008 Steven Watanabe
Chris@16: //
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See
Chris@16: // accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_UNITS_POW_HPP 
Chris@16: #define BOOST_UNITS_POW_HPP
Chris@16: 
Chris@16: #include <boost/math_fwd.hpp>
Chris@16: #include <boost/type_traits/is_integral.hpp>
Chris@16: 
Chris@16: #include <boost/units/operators.hpp>
Chris@16: #include <boost/units/static_rational.hpp>
Chris@16: #include <boost/units/detail/static_rational_power.hpp>
Chris@16: 
Chris@16: /// \file 
Chris@16: /// \brief Raise values to exponents known at compile-time.
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16: namespace units {
Chris@16: 
Chris@16: /// raise a value to a @c static_rational power.
Chris@16: template<class Rat,class Y>
Chris@16: inline typename power_typeof_helper<Y,Rat>::type
Chris@16: pow(const Y& x)
Chris@16: {
Chris@16:     return power_typeof_helper<Y,Rat>::value(x);
Chris@16: }
Chris@16: 
Chris@16: /// raise a value to an integer power.
Chris@16: template<long N,class Y>
Chris@16: inline typename power_typeof_helper<Y,static_rational<N> >::type
Chris@16: pow(const Y& x)
Chris@16: {
Chris@16:     return power_typeof_helper<Y,static_rational<N> >::value(x);
Chris@16: }
Chris@16: 
Chris@16: #ifndef BOOST_UNITS_DOXYGEN
Chris@16: 
Chris@16: /// raise @c T to a @c static_rational power.
Chris@16: template<class T, long N,long D> 
Chris@16: struct power_typeof_helper<T, static_rational<N,D> >                
Chris@16: { 
Chris@16:     typedef typename mpl::if_<boost::is_integral<T>, double, T>::type internal_type;
Chris@16:     typedef detail::static_rational_power_impl<static_rational<N, D>, internal_type> impl;
Chris@16:     typedef typename impl::type type; 
Chris@16:     
Chris@16:     static type value(const T& x)  
Chris@16:     {
Chris@16:         return impl::call(x);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: /// raise @c float to a @c static_rational power.
Chris@16: template<long N,long D> 
Chris@16: struct power_typeof_helper<float, static_rational<N,D> >
Chris@16: {
Chris@16:     // N.B.  pathscale doesn't accept inheritance for some reason.
Chris@16:     typedef power_typeof_helper<double, static_rational<N,D> > base;
Chris@16:     typedef typename base::type type;
Chris@16:     static type value(const double& x)
Chris@16:     {
Chris@16:         return base::value(x);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: #endif
Chris@16: 
Chris@16: /// take the @c static_rational root of a value.
Chris@16: template<class Rat,class Y>
Chris@16: typename root_typeof_helper<Y,Rat>::type
Chris@16: root(const Y& x)
Chris@16: {
Chris@16:     return root_typeof_helper<Y,Rat>::value(x);
Chris@16: }
Chris@16: 
Chris@16: /// take the integer root of a value.
Chris@16: template<long N,class Y>
Chris@16: typename root_typeof_helper<Y,static_rational<N> >::type
Chris@16: root(const Y& x)
Chris@16: {
Chris@16:     return root_typeof_helper<Y,static_rational<N> >::value(x);
Chris@16: }
Chris@16: 
Chris@16: #ifndef BOOST_UNITS_DOXYGEN
Chris@16: 
Chris@16: /// take @c static_rational root of an @c T
Chris@16: template<class T, long N,long D> 
Chris@16: struct root_typeof_helper<T,static_rational<N,D> >
Chris@16: {
Chris@16:     // N.B.  pathscale doesn't accept inheritance for some reason.
Chris@16:     typedef power_typeof_helper<T, static_rational<D,N> > base;
Chris@16:     typedef typename base::type type;
Chris@16:     static type value(const T& x)
Chris@16:     {
Chris@16:         return(base::value(x));
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: #endif
Chris@16: 
Chris@16: } // namespace units
Chris@16: 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #endif // BOOST_UNITS_STATIC_RATIONAL_HPP