[3332] | 1 | //////////////////////////////////////////////////////////////////////////////// |
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| 2 | // The Loki Library |
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| 3 | // Copyright (c) 2001 by Andrei Alexandrescu |
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| 4 | // This code accompanies the book: |
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| 5 | // Alexandrescu, Andrei. "Modern C++ Design: Generic Programming and Design |
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| 6 | // Patterns Applied". Copyright (c) 2001. Addison-Wesley. |
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| 7 | // Permission to use, copy, modify, distribute and sell this software for any |
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| 8 | // purpose is hereby granted without fee, provided that the above copyright |
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| 9 | // notice appear in all copies and that both that copyright notice and this |
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| 10 | // permission notice appear in supporting documentation. |
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| 11 | // The author or Addison-Wesley Longman make no representations about the |
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| 12 | // suitability of this software for any purpose. It is provided "as is" |
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| 13 | // without express or implied warranty. |
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| 14 | // |
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| 15 | // Changes by Orxonox (Reto) |
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| 16 | // Removed all stdInt, etc. type traits and function pointer traits |
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| 17 | // and added UnqualifiedReferredType. |
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| 18 | //////////////////////////////////////////////////////////////////////////////// |
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| 19 | #ifndef LOKI_TYPETRAITS_INC_ |
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| 20 | #define LOKI_TYPETRAITS_INC_ |
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| 21 | |
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| 22 | // $Id: TypeTraits.h 835 2007-08-02 19:39:02Z syntheticpp $ |
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| 23 | |
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| 24 | |
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| 25 | #if (defined _MSC_VER) && (_MSC_VER < 1400) |
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| 26 | #include <string> |
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| 27 | #endif |
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| 28 | |
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| 29 | |
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| 30 | #ifdef _MSC_VER |
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| 31 | #pragma warning( push ) |
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| 32 | #pragma warning( disable : 4180 ) //qualifier applied to function type has no meaning; ignored |
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| 33 | #endif |
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| 34 | |
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| 35 | namespace Loki |
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| 36 | { |
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| 37 | //////////////////////////////////////////////////////////////////////////////// |
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| 38 | // class NullType |
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| 39 | // Used as a placeholder for "no type here" |
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| 40 | // Useful as an end marker in typelists |
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| 41 | //////////////////////////////////////////////////////////////////////////////// |
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| 42 | |
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| 43 | class NullType {}; |
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| 44 | |
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| 45 | //////////////////////////////////////////////////////////////////////////////// |
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| 46 | // class template IsCustomUnsignedInt |
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| 47 | // Offers a means to integrate nonstandard built-in unsigned integral types |
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| 48 | // (such as unsigned __int64 or unsigned long long int) with the TypeTraits |
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| 49 | // class template defined below. |
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| 50 | // Invocation: IsCustomUnsignedInt<T> where T is any type |
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| 51 | // Defines 'value', an enum that is 1 iff T is a custom built-in unsigned |
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| 52 | // integral type |
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| 53 | // Specialize this class template for nonstandard unsigned integral types |
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| 54 | // and define value = 1 in those specializations |
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| 55 | //////////////////////////////////////////////////////////////////////////////// |
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| 56 | |
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| 57 | template <typename T> |
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| 58 | struct IsCustomUnsignedInt |
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| 59 | { |
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| 60 | enum { value = 0 }; |
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| 61 | }; |
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| 62 | |
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| 63 | //////////////////////////////////////////////////////////////////////////////// |
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| 64 | // class template IsCustomSignedInt |
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| 65 | // Offers a means to integrate nonstandard built-in unsigned integral types |
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| 66 | // (such as unsigned __int64 or unsigned long long int) with the TypeTraits |
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| 67 | // class template defined below. |
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| 68 | // Invocation: IsCustomSignedInt<T> where T is any type |
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| 69 | // Defines 'value', an enum that is 1 iff T is a custom built-in signed |
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| 70 | // integral type |
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| 71 | // Specialize this class template for nonstandard unsigned integral types |
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| 72 | // and define value = 1 in those specializations |
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| 73 | //////////////////////////////////////////////////////////////////////////////// |
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| 74 | |
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| 75 | template <typename T> |
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| 76 | struct IsCustomSignedInt |
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| 77 | { |
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| 78 | enum { value = 0 }; |
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| 79 | }; |
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| 80 | |
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| 81 | //////////////////////////////////////////////////////////////////////////////// |
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| 82 | // class template IsCustomFloat |
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| 83 | // Offers a means to integrate nonstandard floating point types with the |
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| 84 | // TypeTraits class template defined below. |
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| 85 | // Invocation: IsCustomFloat<T> where T is any type |
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| 86 | // Defines 'value', an enum that is 1 iff T is a custom built-in |
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| 87 | // floating point type |
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| 88 | // Specialize this class template for nonstandard unsigned integral types |
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| 89 | // and define value = 1 in those specializations |
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| 90 | //////////////////////////////////////////////////////////////////////////////// |
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| 91 | |
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| 92 | template <typename T> |
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| 93 | struct IsCustomFloat |
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| 94 | { |
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| 95 | enum { value = 0 }; |
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| 96 | }; |
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| 97 | |
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| 98 | //////////////////////////////////////////////////////////////////////////////// |
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| 99 | // Helper types for class template TypeTraits defined below |
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| 100 | //////////////////////////////////////////////////////////////////////////////// |
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| 101 | |
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| 102 | namespace Private |
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| 103 | { |
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| 104 | template <typename U> struct AddPointer |
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| 105 | { |
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| 106 | typedef U* Result; |
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| 107 | }; |
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| 108 | |
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| 109 | template <typename U> struct AddPointer<U&> |
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| 110 | { |
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| 111 | typedef U* Result; |
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| 112 | }; |
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| 113 | |
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| 114 | template <class U> struct AddReference |
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| 115 | { |
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| 116 | typedef U & Result; |
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| 117 | }; |
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| 118 | |
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| 119 | template <class U> struct AddReference<U &> |
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| 120 | { |
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| 121 | typedef U & Result; |
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| 122 | }; |
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| 123 | |
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| 124 | template <> struct AddReference<void> |
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| 125 | { |
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| 126 | typedef NullType Result; |
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| 127 | }; |
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| 128 | |
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| 129 | template <class U> struct AddParameterType |
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| 130 | { |
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| 131 | typedef const U & Result; |
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| 132 | }; |
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| 133 | |
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| 134 | template <class U> struct AddParameterType<U &> |
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| 135 | { |
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| 136 | typedef U & Result; |
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| 137 | }; |
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| 138 | |
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| 139 | template <> struct AddParameterType<void> |
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| 140 | { |
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| 141 | typedef NullType Result; |
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| 142 | }; |
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| 143 | }// namespace Private |
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| 144 | |
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| 145 | //////////////////////////////////////////////////////////////////////////////// |
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| 146 | // class template TypeTraits |
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| 147 | // |
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| 148 | // Figures out at compile time various properties of any given type |
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| 149 | // Invocations (T is a type, TypeTraits<T>::Property): |
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| 150 | // |
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| 151 | // - isPointer : returns true if T is a pointer type |
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| 152 | // - PointeeType : returns the type to which T points if T is a pointer |
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| 153 | // type, NullType otherwise |
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| 154 | // - isReference : returns true if T is a reference type |
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| 155 | // - ReferredType : returns the type to which T refers if T is a reference |
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| 156 | // type, NullType otherwise |
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| 157 | // - ParameterType : returns the optimal type to be used as a parameter for |
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| 158 | // functions that take Ts |
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| 159 | // - isConst : returns true if T is a const-qualified type |
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| 160 | // - NonConstType : Type with removed 'const' qualifier from T, if any |
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| 161 | // - isVolatile : returns true if T is a volatile-qualified type |
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| 162 | // - NonVolatileType : Type with removed 'volatile' qualifier from T, if any |
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| 163 | // - UnqualifiedType : Type with removed 'const' and 'volatile' qualifiers from |
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| 164 | // T, if any |
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| 165 | // - ParameterType : returns the optimal type to be used as a parameter |
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| 166 | // for functions that take 'const T's |
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| 167 | // |
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| 168 | //////////////////////////////////////////////////////////////////////////////// |
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| 169 | |
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| 170 | template <typename T> |
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| 171 | class TypeTraits |
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| 172 | { |
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| 173 | private: |
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| 174 | |
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| 175 | template <class U> struct ReferenceTraits |
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| 176 | { |
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| 177 | enum { result = false }; |
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| 178 | typedef U ReferredType; |
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| 179 | }; |
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| 180 | |
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| 181 | template <class U> struct ReferenceTraits<U&> |
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| 182 | { |
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| 183 | enum { result = true }; |
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| 184 | typedef U ReferredType; |
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| 185 | }; |
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| 186 | |
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| 187 | template <class U> struct PointerTraits |
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| 188 | { |
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| 189 | enum { result = false }; |
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| 190 | typedef NullType PointeeType; |
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| 191 | }; |
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| 192 | |
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| 193 | template <class U> struct PointerTraits<U*> |
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| 194 | { |
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| 195 | enum { result = true }; |
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| 196 | typedef U PointeeType; |
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| 197 | }; |
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| 198 | |
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| 199 | template <class U> struct PointerTraits<U*&> |
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| 200 | { |
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| 201 | enum { result = true }; |
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| 202 | typedef U PointeeType; |
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| 203 | }; |
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| 204 | |
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| 205 | template <class U> struct PToMTraits |
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| 206 | { |
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| 207 | enum { result = false }; |
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| 208 | }; |
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| 209 | |
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| 210 | template <class U, class V> struct PToMTraits<U V::*> |
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| 211 | { |
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| 212 | enum { result = true }; |
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| 213 | }; |
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| 214 | |
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| 215 | template <class U, class V> struct PToMTraits<U V::*&> |
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| 216 | { |
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| 217 | enum { result = true }; |
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| 218 | }; |
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| 219 | |
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| 220 | template <class U> struct UnConst |
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| 221 | { |
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| 222 | typedef U Result; |
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| 223 | enum { isConst = 0 }; |
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| 224 | }; |
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| 225 | |
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| 226 | template <class U> struct UnConst<const U> |
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| 227 | { |
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| 228 | typedef U Result; |
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| 229 | enum { isConst = 1 }; |
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| 230 | }; |
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| 231 | |
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| 232 | template <class U> struct UnConst<const U&> |
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| 233 | { |
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| 234 | typedef U& Result; |
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| 235 | enum { isConst = 1 }; |
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| 236 | }; |
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| 237 | |
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| 238 | template <class U> struct UnVolatile |
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| 239 | { |
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| 240 | typedef U Result; |
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| 241 | enum { isVolatile = 0 }; |
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| 242 | }; |
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| 243 | |
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| 244 | template <class U> struct UnVolatile<volatile U> |
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| 245 | { |
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| 246 | typedef U Result; |
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| 247 | enum { isVolatile = 1 }; |
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| 248 | }; |
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| 249 | |
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| 250 | template <class U> struct UnVolatile<volatile U&> |
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| 251 | { |
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| 252 | typedef U& Result; |
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| 253 | enum { isVolatile = 1 }; |
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| 254 | }; |
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| 255 | |
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| 256 | public: |
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| 257 | typedef typename UnConst<T>::Result |
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| 258 | NonConstType; |
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| 259 | typedef typename UnVolatile<T>::Result |
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| 260 | NonVolatileType; |
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| 261 | typedef typename UnVolatile<typename UnConst<T>::Result>::Result |
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| 262 | UnqualifiedType; |
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| 263 | typedef typename PointerTraits<UnqualifiedType>::PointeeType |
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| 264 | PointeeType; |
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| 265 | typedef typename ReferenceTraits<T>::ReferredType |
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| 266 | ReferredType; |
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| 267 | typedef typename ReferenceTraits<typename UnVolatile<typename UnConst<T>::Result>::Result>::ReferredType |
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| 268 | UnqualifiedReferredType; |
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| 269 | |
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| 270 | enum { isConst = UnConst<T>::isConst }; |
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| 271 | enum { isVolatile = UnVolatile<T>::isVolatile }; |
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| 272 | enum { isReference = ReferenceTraits<UnqualifiedType>::result }; |
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| 273 | enum { isPointer = PointerTraits< |
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| 274 | typename ReferenceTraits<UnqualifiedType>::ReferredType >::result}; |
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| 275 | |
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| 276 | }; |
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| 277 | } |
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| 278 | |
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| 279 | #ifdef _MSC_VER |
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| 280 | #pragma warning( pop ) |
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| 281 | #endif // _MSC_VER |
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| 282 | |
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| 283 | |
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| 284 | #endif // end file guardian |
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| 285 | |
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