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_OPERATORS_HPP 
Chris@16: #define BOOST_UNITS_OPERATORS_HPP
Chris@16: 
Chris@16: 
Chris@16: ///
Chris@16: /// \file
Chris@16: /// \brief Compile time operators and typeof helper classes.
Chris@16: /// \details
Chris@16: ///   These operators declare the compile-time operators needed to support dimensional
Chris@16: ///   analysis algebra.  They require the use of Boost.Typeof, emulation or native.
Chris@16: ///   Typeof helper classes define result type for heterogeneous operators on value types.
Chris@16: ///   These must be defined through specialization for powers and roots.
Chris@16: ///
Chris@16: 
Chris@16: #include <boost/static_assert.hpp>
Chris@16: #include <boost/type_traits/is_same.hpp>
Chris@16: 
Chris@16: #include <boost/units/config.hpp>
Chris@16: 
Chris@16: namespace boost {
Chris@16: namespace units {
Chris@16: 
Chris@16: #if BOOST_UNITS_HAS_TYPEOF
Chris@16: 
Chris@16: #ifndef BOOST_UNITS_DOXYGEN
Chris@16: 
Chris@16: // to avoid need for default constructor and eliminate divide by zero errors.
Chris@16: namespace typeof_ {
Chris@16: 
Chris@16: /// INTERNAL ONLY
Chris@16: template<class T> T make();
Chris@16: 
Chris@16: } // namespace typeof_
Chris@16: 
Chris@16: #endif
Chris@16: 
Chris@16: #if (BOOST_UNITS_HAS_BOOST_TYPEOF)
Chris@16: 
Chris@16: template<typename X> struct unary_plus_typeof_helper            
Chris@16: {
Chris@16:     BOOST_TYPEOF_NESTED_TYPEDEF_TPL(nested, (+typeof_::make<X>()))
Chris@16:     typedef typename nested::type type;
Chris@16: };
Chris@16: 
Chris@16: template<typename X> struct unary_minus_typeof_helper           
Chris@16: {
Chris@16:     BOOST_TYPEOF_NESTED_TYPEDEF_TPL(nested, (-typeof_::make<X>()))
Chris@16:     typedef typename nested::type type;
Chris@16: };
Chris@16: 
Chris@16: template<typename X,typename Y> struct add_typeof_helper        
Chris@16: {
Chris@16:     BOOST_TYPEOF_NESTED_TYPEDEF_TPL(nested, (typeof_::make<X>()+typeof_::make<Y>()))
Chris@16:     typedef typename nested::type type;
Chris@16: };
Chris@16: 
Chris@16: template<typename X,typename Y> struct subtract_typeof_helper   
Chris@16: {
Chris@16:     BOOST_TYPEOF_NESTED_TYPEDEF_TPL(nested, (typeof_::make<X>()-typeof_::make<Y>()))
Chris@16:     typedef typename nested::type type;
Chris@16: };
Chris@16: 
Chris@16: template<typename X,typename Y> struct multiply_typeof_helper   
Chris@16: {
Chris@16:     BOOST_TYPEOF_NESTED_TYPEDEF_TPL(nested, (typeof_::make<X>()*typeof_::make<Y>()))
Chris@16:     typedef typename nested::type type;
Chris@16: };
Chris@16: 
Chris@16: template<typename X,typename Y> struct divide_typeof_helper     
Chris@16: {
Chris@16:     BOOST_TYPEOF_NESTED_TYPEDEF_TPL(nested, (typeof_::make<X>()/typeof_::make<Y>()))
Chris@16:     typedef typename nested::type type;
Chris@16: };
Chris@16: 
Chris@16: #elif (BOOST_UNITS_HAS_MWERKS_TYPEOF)
Chris@16: 
Chris@16: template<typename X> struct unary_plus_typeof_helper            { typedef __typeof__((+typeof_::make<X>())) type; };
Chris@16: template<typename X> struct unary_minus_typeof_helper           { typedef __typeof__((-typeof_::make<X>())) type; };
Chris@16: 
Chris@16: template<typename X,typename Y> struct add_typeof_helper        { typedef __typeof__((typeof_::make<X>()+typeof_::make<Y>())) type; };
Chris@16: template<typename X,typename Y> struct subtract_typeof_helper   { typedef __typeof__((typeof_::make<X>()-typeof_::make<Y>())) type; };
Chris@16: template<typename X,typename Y> struct multiply_typeof_helper   { typedef __typeof__((typeof_::make<X>()*typeof_::make<Y>())) type; };
Chris@16: template<typename X,typename Y> struct divide_typeof_helper     { typedef __typeof__((typeof_::make<X>()/typeof_::make<Y>())) type; };
Chris@16: 
Chris@16: #elif (BOOST_UNITS_HAS_GNU_TYPEOF) || defined(BOOST_UNITS_DOXYGEN)
Chris@16: 
Chris@16: template<typename X> struct unary_plus_typeof_helper            { typedef typeof((+typeof_::make<X>())) type; };
Chris@16: template<typename X> struct unary_minus_typeof_helper           { typedef typeof((-typeof_::make<X>())) type; };
Chris@16: 
Chris@16: template<typename X,typename Y> struct add_typeof_helper        { typedef typeof((typeof_::make<X>()+typeof_::make<Y>())) type; };
Chris@16: template<typename X,typename Y> struct subtract_typeof_helper   { typedef typeof((typeof_::make<X>()-typeof_::make<Y>())) type; };
Chris@16: template<typename X,typename Y> struct multiply_typeof_helper   { typedef typeof((typeof_::make<X>()*typeof_::make<Y>())) type; };
Chris@16: template<typename X,typename Y> struct divide_typeof_helper     { typedef typeof((typeof_::make<X>()/typeof_::make<Y>())) type; };
Chris@16: 
Chris@16: #endif
Chris@16: 
Chris@16: #else // BOOST_UNITS_HAS_TYPEOF
Chris@16: 
Chris@16: template<typename X> struct unary_plus_typeof_helper            { typedef X type; };
Chris@16: template<typename X> struct unary_minus_typeof_helper           { typedef X type; };
Chris@16: 
Chris@16: template<typename X,typename Y> struct add_typeof_helper        { BOOST_STATIC_ASSERT((is_same<X,Y>::value == true)); typedef X type; };
Chris@16: template<typename X,typename Y> struct subtract_typeof_helper   { BOOST_STATIC_ASSERT((is_same<X,Y>::value == true)); typedef X type; };
Chris@16: template<typename X,typename Y> struct multiply_typeof_helper   { BOOST_STATIC_ASSERT((is_same<X,Y>::value == true)); typedef X type; };
Chris@16: template<typename X,typename Y> struct divide_typeof_helper     { BOOST_STATIC_ASSERT((is_same<X,Y>::value == true)); typedef X type; };
Chris@16: 
Chris@16: #endif // BOOST_UNITS_HAS_TYPEOF
Chris@16: 
Chris@16: template<typename X,typename Y> struct power_typeof_helper;
Chris@16: template<typename X,typename Y> struct root_typeof_helper;
Chris@16: 
Chris@16: #ifdef BOOST_UNITS_DOXYGEN
Chris@16: 
Chris@16: /// A helper used by @c pow to raise
Chris@16: /// a runtime object to a compile time
Chris@16: /// known exponent.  This template is intended to
Chris@16: /// be specialized.  All specializations must
Chris@16: /// conform to the interface shown here.
Chris@16: /// @c Exponent will be either the exponent
Chris@16: /// passed to @c pow or @c static_rational<N>
Chris@16: /// for and integer argument, N.
Chris@16: template<typename BaseType, typename Exponent>
Chris@16: struct power_typeof_helper
Chris@16: {
Chris@16:     /// specifies the result type
Chris@16:     typedef detail::unspecified type;
Chris@16:     /// Carries out the runtime calculation.
Chris@16:     static type value(const BaseType& base);
Chris@16: };
Chris@16: 
Chris@16: /// A helper used by @c root to take a root
Chris@16: /// of a runtime object using a compile time
Chris@16: /// known index.  This template is intended to
Chris@16: /// be specialized.  All specializations must
Chris@16: /// conform to the interface shown here.
Chris@16: /// @c Index will be either the type
Chris@16: /// passed to @c pow or @c static_rational<N>
Chris@16: /// for and integer argument, N.
Chris@16: template<typename Radicand, typename Index>
Chris@16: struct root_typeof_helper
Chris@16: {
Chris@16:     /// specifies the result type
Chris@16:     typedef detail::unspecified type;
Chris@16:     /// Carries out the runtime calculation.
Chris@16:     static type value(const Radicand& base);
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_OPERATORS_HPP