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Sacado_Fad_Expression.hpp
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4 // Sacado Package
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7 // Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
8 // the U.S. Government retains certain rights in this software.
9 //
10 // This library is free software; you can redistribute it and/or modify
11 // it under the terms of the GNU Lesser General Public License as
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28 //
29 // The forward-mode AD classes in Sacado are a derivative work of the
30 // expression template classes in the Fad package by Nicolas Di Cesare.
31 // The following banner is included in the original Fad source code:
32 //
33 // ************ DO NOT REMOVE THIS BANNER ****************
34 //
35 // Nicolas Di Cesare <Nicolas.Dicesare@ann.jussieu.fr>
36 // http://www.ann.jussieu.fr/~dicesare
37 //
38 // CEMRACS 98 : C++ courses,
39 // templates : new C++ techniques
40 // for scientific computing
41 //
42 //********************************************************
43 //
44 // A short implementation ( not all operators and
45 // functions are overloaded ) of 1st order Automatic
46 // Differentiation in forward mode (FAD) using
47 // EXPRESSION TEMPLATES.
48 //
49 //********************************************************
50 // @HEADER
51 
52 #ifndef SACADO_FAD_EXPRESSION_HPP
53 #define SACADO_FAD_EXPRESSION_HPP
54 
55 #include "Sacado_Traits.hpp"
57 
58 namespace Sacado {
59 
60  namespace Fad {
61 
63 
70  template <typename> struct BaseExpr {};
71 
72  struct ExprSpecDefault {};
73  template <typename ExprT> struct ExprSpec {
75  };
76 
78 
82  template <typename ExprT, typename Spec> class Expr {};
83 
84  template <typename ExprT, typename Spec>
85  struct ExprSpec< Expr<ExprT,Spec> > {
86  typedef Spec type;
87  };
88 
90 
95  template <typename T>
96  struct ExprLevel {
97  static const unsigned value = 0;
98  };
99 
100  template <typename T>
101  struct ExprLevel< Expr<T> > {
102  static const unsigned value =
104  };
105 
107  template <typename T>
108  struct IsFadExpr {
109  static const bool value = false;
110  };
111 
112  template <typename T>
113  struct IsFadExpr< Expr<T> > {
114  static const bool value = true;
115  };
116 
118 
121  template <typename ConstT>
122  class ConstExpr {
123 
124  public:
125 
127  typedef ConstT value_type;
128 
131 
133  typedef ConstT base_expr_type;
134 
137  ConstExpr(const ConstT& constant) : constant_(constant) {}
138 
141  const ConstT& val() const { return constant_; }
142 
145  const ConstT& val(int j) const { return constant_; }
146 
147  protected:
148 
150  const ConstT& constant_;
151 
152  }; // class ConstExpr
153 
154  } // namespace Fad
155 
156  template <typename T>
157  struct IsExpr< Fad::Expr<T> > {
158  static const bool value = true;
159  };
160 
161  template <typename T>
162  struct BaseExprType< Fad::Expr<T> > {
164  };
165 
166  template <typename T>
167  struct ValueType< Fad::ConstExpr<T> > {
169  };
170 
171 } // namespace Sacado
172 
173 #include "Sacado_SFINAE_Macros.hpp"
174 
175 #endif // SACADO_FAD_EXPRESSION_HPP
Wrapper for a generic expression template.
ScalarType< value_type >::type scalar_type
Typename of scalar&#39;s (which may be different from ConstT)
Constant expression template.
const ConstT & constant_
The constant.
static const bool value
Is a type an expression.
#define KOKKOS_INLINE_FUNCTION
#define T
Definition: Sacado_rad.hpp:573
Determine whether a given type is an expression.
Meta-function for determining concrete base expression.
Get the base Fad type from a view/expression.
KOKKOS_INLINE_FUNCTION ConstExpr(const ConstT &constant)
Constructor.
ConstT base_expr_type
Typename of base-expressions.
Meta-function for determining nesting with an expression.
KOKKOS_INLINE_FUNCTION const ConstT & val(int j) const
Return value of operation.
static const unsigned value
ConstT value_type
Typename of argument values.
Base template specification for ValueType.
KOKKOS_INLINE_FUNCTION const ConstT & val() const
Return value of operation.