Meta.h revision c981c48f5bc9aefeffc0bcb0cc3934c2fae179dd
1868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)// This file is part of Eigen, a lightweight C++ template library 2868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)// for linear algebra. 3868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)// 4868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)// Copyright (C) 2008-2009 Gael Guennebaud <gael.guennebaud@inria.fr> 5f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// Copyright (C) 2006-2008 Benoit Jacob <jacob.benoit.1@gmail.com> 65d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)// 75d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)// This Source Code Form is subject to the terms of the Mozilla 8f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)// Public License v. 2.0. If a copy of the MPL was not distributed 95d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)// with this file, You can obtain one at http://mozilla.org/MPL/2.0/. 10868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles) 11868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)#ifndef EIGEN_META_H 12a36e5920737c6adbddd3e43b760e5de8431db6e0Torne (Richard Coles)#define EIGEN_META_H 13f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles) 14868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)namespace Eigen { 15868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles) 16a36e5920737c6adbddd3e43b760e5de8431db6e0Torne (Richard Coles)namespace internal { 17868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles) 18868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)/** \internal 19868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles) * \file Meta.h 20868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles) * This file contains generic metaprogramming classes which are not specifically related to Eigen. 211320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci * \note In case you wonder, yes we're aware that Boost already provides all these features, 22868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles) * we however don't want to add a dependency to Boost. 23868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles) */ 241320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci 25868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)struct true_type { enum { value = 1 }; }; 26868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)struct false_type { enum { value = 0 }; }; 27868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles) 281320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tuccitemplate<bool Condition, typename Then, typename Else> 29868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)struct conditional { typedef Then type; }; 30868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles) 31868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)template<typename Then, typename Else> 32868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)struct conditional <false, Then, Else> { typedef Else type; }; 33868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles) 346d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles)template<typename T, typename U> struct is_same { enum { value = 0 }; }; 35868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)template<typename T> struct is_same<T,T> { enum { value = 1 }; }; 36868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles) 37868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)template<typename T> struct remove_reference { typedef T type; }; 38868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)template<typename T> struct remove_reference<T&> { typedef T type; }; 39868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles) 40868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)template<typename T> struct remove_pointer { typedef T type; }; 411320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tuccitemplate<typename T> struct remove_pointer<T*> { typedef T type; }; 42868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)template<typename T> struct remove_pointer<T*const> { typedef T type; }; 4323730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles) 4423730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles)template <class T> struct remove_const { typedef T type; }; 4523730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles)template <class T> struct remove_const<const T> { typedef T type; }; 4623730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles)template <class T> struct remove_const<const T[]> { typedef T type[]; }; 4723730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles)template <class T, unsigned int Size> struct remove_const<const T[Size]> { typedef T type[Size]; }; 4823730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles) 4923730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles)template<typename T> struct remove_all { typedef T type; }; 5023730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles)template<typename T> struct remove_all<const T> { typedef typename remove_all<T>::type type; }; 5123730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles)template<typename T> struct remove_all<T const&> { typedef typename remove_all<T>::type type; }; 5223730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles)template<typename T> struct remove_all<T&> { typedef typename remove_all<T>::type type; }; 531320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tuccitemplate<typename T> struct remove_all<T const*> { typedef typename remove_all<T>::type type; }; 5423730a6e56a168d1879203e4b3819bb36e3d8f1fTorne (Richard Coles)template<typename T> struct remove_all<T*> { typedef typename remove_all<T>::type type; }; 55868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles) 56868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)template<typename T> struct is_arithmetic { enum { value = false }; }; 571320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tuccitemplate<> struct is_arithmetic<float> { enum { value = true }; }; 58f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)template<> struct is_arithmetic<double> { enum { value = true }; }; 59f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)template<> struct is_arithmetic<long double> { enum { value = true }; }; 603551c9c881056c480085172ff9840cab31610854Torne (Richard Coles)template<> struct is_arithmetic<bool> { enum { value = true }; }; 613551c9c881056c480085172ff9840cab31610854Torne (Richard Coles)template<> struct is_arithmetic<char> { enum { value = true }; }; 62f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)template<> struct is_arithmetic<signed char> { enum { value = true }; }; 63f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)template<> struct is_arithmetic<unsigned char> { enum { value = true }; }; 64f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)template<> struct is_arithmetic<signed short> { enum { value = true }; }; 65f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)template<> struct is_arithmetic<unsigned short>{ enum { value = true }; }; 66868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)template<> struct is_arithmetic<signed int> { enum { value = true }; }; 67868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)template<> struct is_arithmetic<unsigned int> { enum { value = true }; }; 681320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tuccitemplate<> struct is_arithmetic<signed long> { enum { value = true }; }; 69868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles)template<> struct is_arithmetic<unsigned long> { enum { value = true }; }; 70868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles) 71a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles)template <typename T> struct add_const { typedef const T type; }; 72f2477e01787aa58f445919b809d89e252beef54fTorne (Richard Coles)template <typename T> struct add_const<T&> { typedef T& type; }; 735d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 746d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles)template <typename T> struct is_const { enum { value = 0 }; }; 751320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tuccitemplate <typename T> struct is_const<T const> { enum { value = 1 }; }; 766d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles) 776d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles)template<typename T> struct add_const_on_value_type { typedef const T type; }; 786d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles)template<typename T> struct add_const_on_value_type<T&> { typedef T const& type; }; 796d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles)template<typename T> struct add_const_on_value_type<T*> { typedef T const* type; }; 805d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)template<typename T> struct add_const_on_value_type<T* const> { typedef T const* const type; }; 815d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)template<typename T> struct add_const_on_value_type<T const* const> { typedef T const* const type; }; 825d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 835d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)/** \internal Allows to enable/disable an overload 845d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) * according to a compile time condition. 855d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) */ 865d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)template<bool Condition, typename T> struct enable_if; 875d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 885d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)template<typename T> struct enable_if<true,T> 895d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles){ typedef T type; }; 905d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 915d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 925d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 935d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)/** \internal 945d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) * A base class do disable default copy ctor and copy assignement operator. 955d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) */ 965d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)class noncopyable 975d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles){ 985d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) noncopyable(const noncopyable&); 995d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) const noncopyable& operator=(const noncopyable&); 1005d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)protected: 1015d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) noncopyable() {} 1025d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) ~noncopyable() {} 1035d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)}; 1045d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 1055d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 1065d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)/** \internal 1075d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) * Convenient struct to get the result type of a unary or binary functor. 1085d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) * 1095d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) * It supports both the current STL mechanism (using the result_type member) as well as 1105d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) * upcoming next STL generation (using a templated result member). 1115d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) * If none of these members is provided, then the type of the first argument is returned. FIXME, that behavior is a pretty bad hack. 1125d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) */ 1135d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)template<typename T> struct result_of {}; 1145d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 1155d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)struct has_none {int a[1];}; 1165d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)struct has_std_result_type {int a[2];}; 1175d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)struct has_tr1_result {int a[3];}; 1185d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 1195d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)template<typename Func, typename ArgType, int SizeOf=sizeof(has_none)> 1205d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)struct unary_result_of_select {typedef ArgType type;}; 1215d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 1225d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)template<typename Func, typename ArgType> 1235d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)struct unary_result_of_select<Func, ArgType, sizeof(has_std_result_type)> {typedef typename Func::result_type type;}; 1245d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 1255d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)template<typename Func, typename ArgType> 126struct unary_result_of_select<Func, ArgType, sizeof(has_tr1_result)> {typedef typename Func::template result<Func(ArgType)>::type type;}; 127 128template<typename Func, typename ArgType> 129struct result_of<Func(ArgType)> { 130 template<typename T> 131 static has_std_result_type testFunctor(T const *, typename T::result_type const * = 0); 132 template<typename T> 133 static has_tr1_result testFunctor(T const *, typename T::template result<T(ArgType)>::type const * = 0); 134 static has_none testFunctor(...); 135 136 // note that the following indirection is needed for gcc-3.3 137 enum {FunctorType = sizeof(testFunctor(static_cast<Func*>(0)))}; 138 typedef typename unary_result_of_select<Func, ArgType, FunctorType>::type type; 139}; 140 141template<typename Func, typename ArgType0, typename ArgType1, int SizeOf=sizeof(has_none)> 142struct binary_result_of_select {typedef ArgType0 type;}; 143 144template<typename Func, typename ArgType0, typename ArgType1> 145struct binary_result_of_select<Func, ArgType0, ArgType1, sizeof(has_std_result_type)> 146{typedef typename Func::result_type type;}; 147 148template<typename Func, typename ArgType0, typename ArgType1> 149struct binary_result_of_select<Func, ArgType0, ArgType1, sizeof(has_tr1_result)> 150{typedef typename Func::template result<Func(ArgType0,ArgType1)>::type type;}; 151 152template<typename Func, typename ArgType0, typename ArgType1> 153struct result_of<Func(ArgType0,ArgType1)> { 154 template<typename T> 155 static has_std_result_type testFunctor(T const *, typename T::result_type const * = 0); 156 template<typename T> 157 static has_tr1_result testFunctor(T const *, typename T::template result<T(ArgType0,ArgType1)>::type const * = 0); 158 static has_none testFunctor(...); 159 160 // note that the following indirection is needed for gcc-3.3 161 enum {FunctorType = sizeof(testFunctor(static_cast<Func*>(0)))}; 162 typedef typename binary_result_of_select<Func, ArgType0, ArgType1, FunctorType>::type type; 163}; 164 165/** \internal In short, it computes int(sqrt(\a Y)) with \a Y an integer. 166 * Usage example: \code meta_sqrt<1023>::ret \endcode 167 */ 168template<int Y, 169 int InfX = 0, 170 int SupX = ((Y==1) ? 1 : Y/2), 171 bool Done = ((SupX-InfX)<=1 ? true : ((SupX*SupX <= Y) && ((SupX+1)*(SupX+1) > Y))) > 172 // use ?: instead of || just to shut up a stupid gcc 4.3 warning 173class meta_sqrt 174{ 175 enum { 176 MidX = (InfX+SupX)/2, 177 TakeInf = MidX*MidX > Y ? 1 : 0, 178 NewInf = int(TakeInf) ? InfX : int(MidX), 179 NewSup = int(TakeInf) ? int(MidX) : SupX 180 }; 181 public: 182 enum { ret = meta_sqrt<Y,NewInf,NewSup>::ret }; 183}; 184 185template<int Y, int InfX, int SupX> 186class meta_sqrt<Y, InfX, SupX, true> { public: enum { ret = (SupX*SupX <= Y) ? SupX : InfX }; }; 187 188/** \internal determines whether the product of two numeric types is allowed and what the return type is */ 189template<typename T, typename U> struct scalar_product_traits; 190 191template<typename T> struct scalar_product_traits<T,T> 192{ 193 //enum { Cost = NumTraits<T>::MulCost }; 194 typedef T ReturnType; 195}; 196 197template<typename T> struct scalar_product_traits<T,std::complex<T> > 198{ 199 //enum { Cost = 2*NumTraits<T>::MulCost }; 200 typedef std::complex<T> ReturnType; 201}; 202 203template<typename T> struct scalar_product_traits<std::complex<T>, T> 204{ 205 //enum { Cost = 2*NumTraits<T>::MulCost }; 206 typedef std::complex<T> ReturnType; 207}; 208 209// FIXME quick workaround around current limitation of result_of 210// template<typename Scalar, typename ArgType0, typename ArgType1> 211// struct result_of<scalar_product_op<Scalar>(ArgType0,ArgType1)> { 212// typedef typename scalar_product_traits<typename remove_all<ArgType0>::type, typename remove_all<ArgType1>::type>::ReturnType type; 213// }; 214 215template<typename T> struct is_diagonal 216{ enum { ret = false }; }; 217 218template<typename T> struct is_diagonal<DiagonalBase<T> > 219{ enum { ret = true }; }; 220 221template<typename T> struct is_diagonal<DiagonalWrapper<T> > 222{ enum { ret = true }; }; 223 224template<typename T, int S> struct is_diagonal<DiagonalMatrix<T,S> > 225{ enum { ret = true }; }; 226 227} // end namespace internal 228 229} // end namespace Eigen 230 231#endif // EIGEN_META_H 232