[7266] | 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-Welsey 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 Grieder) |
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| 16 | // Removed templates we didn't need |
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| 17 | //////////////////////////////////////////////////////////////////////////////// |
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| 18 | #ifndef LOKI_TYPEMANIP_INC_ |
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| 19 | #define LOKI_TYPEMANIP_INC_ |
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| 20 | |
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| 21 | // $Id: TypeManip.h 749 2006-10-17 19:49:26Z syntheticpp $ |
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| 22 | |
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| 23 | |
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| 24 | namespace Loki |
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| 25 | { |
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| 26 | //////////////////////////////////////////////////////////////////////////////// |
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| 27 | // class template Int2Type |
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| 28 | // Converts each integral constant into a unique type |
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| 29 | // Invocation: Int2Type<v> where v is a compile-time constant integral |
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| 30 | // Defines 'value', an enum that evaluates to v |
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| 31 | //////////////////////////////////////////////////////////////////////////////// |
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| 32 | |
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| 33 | template <int v> |
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| 34 | struct Int2Type |
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| 35 | { |
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| 36 | enum { value = v }; |
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| 37 | }; |
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| 38 | |
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| 39 | //////////////////////////////////////////////////////////////////////////////// |
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| 40 | // class template Type2Type |
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| 41 | // Converts each type into a unique, insipid type |
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| 42 | // Invocation Type2Type<T> where T is a type |
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| 43 | // Defines the type OriginalType which maps back to T |
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| 44 | //////////////////////////////////////////////////////////////////////////////// |
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| 45 | |
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| 46 | template <typename T> |
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| 47 | struct Type2Type |
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| 48 | { |
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| 49 | typedef T OriginalType; |
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| 50 | }; |
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| 51 | |
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| 52 | //////////////////////////////////////////////////////////////////////////////// |
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| 53 | // class template Select |
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| 54 | // Selects one of two types based upon a boolean constant |
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| 55 | // Invocation: Select<flag, T, U>::Result |
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| 56 | // where: |
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| 57 | // flag is a compile-time boolean constant |
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| 58 | // T and U are types |
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| 59 | // Result evaluates to T if flag is true, and to U otherwise. |
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| 60 | //////////////////////////////////////////////////////////////////////////////// |
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| 61 | |
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| 62 | template <bool flag, typename T, typename U> |
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| 63 | struct Select |
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| 64 | { |
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| 65 | typedef T Result; |
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| 66 | }; |
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| 67 | template <typename T, typename U> |
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| 68 | struct Select<false, T, U> |
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| 69 | { |
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| 70 | typedef U Result; |
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| 71 | }; |
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| 72 | |
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| 73 | //////////////////////////////////////////////////////////////////////////////// |
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| 74 | // class template IsSameType |
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| 75 | // Return true iff two given types are the same |
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| 76 | // Invocation: SameType<T, U>::value |
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| 77 | // where: |
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| 78 | // T and U are types |
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| 79 | // Result evaluates to true iff U == T (types equal) |
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| 80 | //////////////////////////////////////////////////////////////////////////////// |
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| 81 | |
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| 82 | template <typename T, typename U> |
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| 83 | struct IsSameType |
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| 84 | { |
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| 85 | enum { value = false }; |
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| 86 | }; |
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| 87 | |
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| 88 | template <typename T> |
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| 89 | struct IsSameType<T,T> |
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| 90 | { |
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| 91 | enum { value = true }; |
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| 92 | }; |
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| 93 | |
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| 94 | } // namespace Loki |
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| 95 | |
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| 96 | |
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| 97 | #endif // end file guardian |
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| 98 | |
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