| 1 | #ifndef __XIOS_VISITABLE_HPP |
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| 2 | #define __XIOS_VISITABLE_HPP |
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| 3 | |
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| 4 | #include "visitor.hpp" |
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| 5 | #include <vector> |
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| 6 | |
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| 7 | namespace xios { |
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| 8 | |
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| 9 | template <typename R, typename ParamType> |
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| 10 | struct DefaultCatchAll |
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| 11 | { |
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| 12 | static R OnUnknownVisitor(ParamType&, CBaseVisitor&) |
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| 13 | { return R(); } |
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| 14 | }; |
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| 15 | |
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| 16 | //////////////////////////////////////////////////////////////////////////////// |
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| 17 | // class template CBaseVisitable |
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| 18 | //////////////////////////////////////////////////////////////////////////////// |
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| 19 | template |
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| 20 | < |
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| 21 | typename R = void, |
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| 22 | template <typename, class> class CatchAll = DefaultCatchAll, |
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| 23 | bool ConstVisitable = false |
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| 24 | > |
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| 25 | class CBaseVisitable; |
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| 26 | |
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| 27 | template<typename R,template <typename, class> class CatchAll> |
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| 28 | class CBaseVisitable<R, CatchAll, false> |
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| 29 | { |
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| 30 | public: |
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| 31 | typedef R ReturnType; |
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| 32 | virtual ~CBaseVisitable() {} |
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| 33 | virtual ReturnType apply(CBaseVisitor&) = 0; |
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| 34 | virtual void apply(std::vector<CBaseVisitor*>&) = 0; |
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| 35 | |
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| 36 | protected: // give access only to the hierarchy |
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| 37 | template <class T> |
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| 38 | static ReturnType applyImpl(T& visited, CBaseVisitor& guest) |
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| 39 | { |
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| 40 | // Apply the CVisitor |
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| 41 | if (CVisitor<T,R>* p = dynamic_cast<CVisitor<T,R>*>(&guest)) |
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| 42 | { |
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| 43 | return p->operate(visited); |
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| 44 | } |
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| 45 | return CatchAll<R, T>::OnUnknownVisitor(visited, guest); |
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| 46 | } |
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| 47 | }; |
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| 48 | |
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| 49 | template<typename R,template <typename, class> class CatchAll> |
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| 50 | class CBaseVisitable<R, CatchAll, true> |
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| 51 | { |
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| 52 | public: |
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| 53 | typedef R ReturnType; |
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| 54 | virtual ~CBaseVisitable() {} |
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| 55 | virtual ReturnType apply(CBaseVisitor&) const = 0; |
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| 56 | virtual void apply(std::vector<CBaseVisitor*>&) const = 0; |
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| 57 | |
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| 58 | protected: // give access only to the hierarchy |
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| 59 | template <class T> |
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| 60 | static ReturnType applyImpl(const T& visited, CBaseVisitor& guest) |
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| 61 | { |
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| 62 | // Apply the CVisitor |
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| 63 | if (CVisitor<T,R>* p = dynamic_cast<CVisitor<T,R, true>*>(&guest)) |
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| 64 | { |
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| 65 | return p->operate(visited); |
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| 66 | } |
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| 67 | return CatchAll<R, T>::OnUnknownVisitor(const_cast<T&>(visited), guest); |
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| 68 | } |
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| 69 | }; |
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| 70 | |
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| 71 | //////////////////////////////////////////////////////////////////////////////// |
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| 72 | /// Put it in every class that you want to make guest |
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| 73 | /// functions (in addition to deriving it from CBaseVisitable<R>) |
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| 74 | //////////////////////////////////////////////////////////////////////////////// |
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| 75 | #define DEFINE_VISITABLE() \ |
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| 76 | virtual ReturnType apply(::xios::CBaseVisitor& guest) \ |
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| 77 | { return applyImpl(*this, guest); } \ |
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| 78 | virtual void apply(std::vector<CBaseVisitor*>& guests) \ |
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| 79 | { \ |
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| 80 | for (std::vector<CBaseVisitor*>::iterator it = guests.begin(); it != guests.end(); ++it) \ |
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| 81 | apply(*(*it)); \ |
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| 82 | } |
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| 83 | //////////////////////////////////////////////////////////////////////////////// |
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| 84 | /// Put it in every class that you want to make guest by const member |
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| 85 | /// functions (in addition to deriving it from CBaseVisitable<R>) |
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| 86 | //////////////////////////////////////////////////////////////////////////////// |
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| 87 | #define DEFINE_CONST_VISITABLE() \ |
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| 88 | virtual ReturnType apply(::xios::CBaseVisitor& guest) const \ |
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| 89 | { return applyImpl(*this, guest); } \ |
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| 90 | virtual void apply(std::vector<CBaseVisitor*>& guests) const \ |
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| 91 | { \ |
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| 92 | for (std::vector<CBaseVisitor*>::iterator it = guests.begin(); it != guests.end(); ++it) \ |
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| 93 | apply(*(*it)); \ |
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| 94 | } |
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| 95 | |
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| 96 | class CGenericTransformation : public virtual CBaseVisitable<> |
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| 97 | { |
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| 98 | public: |
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| 99 | DEFINE_VISITABLE() |
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| 100 | }; |
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| 101 | |
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| 102 | } |
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| 103 | #endif // __XIOS_VISITABLE_HPP |
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