add pimple/rimpl idiom

git-svn-id: svn://svn.code.sf.net/p/loki-lib/code/trunk@471 7ec92016-0320-0410-acc4-a06ded1c099a

include/loki/Pimpl.h

@@ -0,0 +1,272 @@
+////////////////////////////////////////////////////////////////////////////////
+// The Loki Library
+// Copyright (c) 2006 Peter Kümmel
+// Permission to use, copy, modify, distribute and sell this software for any 
+//     purpose is hereby granted without fee, provided that the above copyright 
+//     notice appear in all copies and that both that copyright notice and this 
+//     permission notice appear in supporting documentation.
+// The author makes no representations about the 
+//     suitability of this software for any purpose. It is provided "as is" 
+//     without express or implied warranty.
+////////////////////////////////////////////////////////////////////////////////
+#ifndef LOKI_PIMPL_H
+#define LOKI_PIMPL_H
+
+#include <loki/TypeTraits.h>
+
+
+#ifndef LOKI_INHERITED_PIMPL_NAME
+#define LOKI_INHERITED_PIMPL_NAME pimpl
+#endif
+
+#ifndef LOKI_INHERITED_RIMPL_NAME
+#define LOKI_INHERITED_RIMPL_NAME rimpl
+#endif
+
+namespace Loki
+{
+    template<class T>
+    struct Impl;
+
+
+    /////////////////////
+    // creation policies
+    /////////////////////
+    // hard coded creation prefered
+
+
+    /////////////////////
+    // destroy policies
+    /////////////////////
+    template<class T>
+    struct AutoDeletePimpl
+    {
+        static void Destroy(T ptr)
+        { 
+            typedef char T_must_be_defined[ 
+                    sizeof(typename TypeTraits<T>::PointeeType) ? 1 : -1 ];
+            delete ptr; 
+            ptr = 0;
+        }
+    };
+
+    template<class T>
+    struct DontDeletePimpl
+    {
+        static void Destroy(T)
+        {}
+    };
+
+
+    /////////////////////
+    // Lifetime manager
+    /////////////////////
+
+    template
+    <
+        class Impl,
+        class Ptr,
+        template<class> class Del
+    >
+    struct PimplLife
+    {
+        PimplLife();
+        ~PimplLife();
+
+        template<class T>
+        operator T&();
+
+        Ptr Create();
+
+        Ptr ptr;
+    };
+
+
+    namespace Private
+    {
+        template<class T> 
+        struct HaveAPimplLife
+        {
+            T life;
+        };
+    }
+
+
+
+    /////////////////////
+    // Pimpl usage policies
+    /////////////////////
+
+    template<class Impl, typename Ptr, template<class> class Del>
+    class DeclaredPimpl : private Private::HaveAPimplLife<PimplLife<Impl,Ptr,Del> >
+    {
+        typedef Private::HaveAPimplLife<PimplLife<Impl,Ptr,Del> > Life;
+
+    public:
+        Ptr operator->() const
+        {
+            return ptr;
+        }
+
+        Impl& operator*() const
+        {
+            return *ptr;
+        }
+    
+    protected:
+        DeclaredPimpl() : ptr(Life::life.Create())
+        {}
+
+    private:
+        const Ptr ptr;
+    };
+
+    template<class Impl, typename Ptr, template<class> class Del>
+    class InheritedPimpl : private Private::HaveAPimplLife<PimplLife<Impl,Ptr,Del> >
+    {    
+        typedef Private::HaveAPimplLife<PimplLife<Impl,Ptr,Del> > Life;
+
+    public:
+        const Ptr LOKI_INHERITED_PIMPL_NAME;
+
+    protected:
+        InheritedPimpl() : LOKI_INHERITED_PIMPL_NAME(Life::life.Create())
+        {}
+    };
+
+    /////////////////////
+    // Rimpl usage policies
+    /////////////////////
+
+    template<class Impl, typename PointerPolicy, template<class> class DeletePolicy>
+    class DeclaredRimpl : public Impl
+    {
+    protected:
+        DeclaredRimpl()
+        {}
+    };
+
+
+    template<class Impl, typename Ptr, template<class> class Del>
+    class InheritedRimpl : private Private::HaveAPimplLife<PimplLife<Impl,Ptr,Del> >
+    {
+        typedef Private::HaveAPimplLife<PimplLife<Impl,Ptr,Del> > Life;
+
+    public:
+        Impl& LOKI_INHERITED_RIMPL_NAME;
+
+    protected:
+        InheritedRimpl() :
+            LOKI_INHERITED_RIMPL_NAME(*Life::life.Create())
+        {}
+
+    private:
+        InheritedRimpl& operator=(const InheritedRimpl&);
+    };
+
+
+
+
+    /////////////////////
+    // Wrapper for "pointer to implementation" alias pimpl.
+    // Impl: implementation class
+    // PointerTypePolicy: arbitrary pointer implementation
+    // DeletePolicy: delete implementation object on destruction of PtrImpl
+    // UsagePolicy: how to access the stored pointer, as pointer, checked, unchecked
+    /////////////////////
+
+
+    template
+    <
+        class Impl,
+        class PointerPolicy = Impl*,
+        template<class> class DeletePolicy = AutoDeletePimpl,
+        template<class,class,template<class> class> class UsagePolicy = InheritedPimpl
+    >
+    class PtrImpl : public UsagePolicy<Impl,PointerPolicy,DeletePolicy>
+    {
+        typedef PimplLife<Impl,PointerPolicy,DeletePolicy> Life;
+
+    public:
+
+        typedef Impl ImplType;
+        typedef PointerPolicy PointerType;
+    
+        PtrImpl() : UsagePolicy<Impl,PointerPolicy,DeletePolicy>()//Private::HaveALife<Life>::life.Create())
+        {}
+
+        PtrImpl(PointerPolicy pimpl) : UsagePolicy<Impl,PointerPolicy,DeletePolicy>(pimpl)
+        {}
+
+        virtual ~PtrImpl()
+        {}
+    };
+
+    
+    /////////////////////
+    // Predefined convenience "templated typedef"
+    /////////////////////
+
+
+    template<class T>
+    struct Pimpl
+    {
+        typedef PtrImpl
+        <
+            Impl<T>,
+            Impl<T>*,
+            AutoDeletePimpl,
+            DeclaredPimpl
+        >
+        Type;
+
+        typedef PtrImpl
+        <
+            Impl<T>,
+            Impl<T>*,
+            AutoDeletePimpl,
+            InheritedPimpl
+        >
+        Owner;
+    };
+
+
+    template<class T>
+    struct Rimpl
+    {
+
+        typedef PtrImpl
+        <
+            Impl<T>,
+            Impl<T>*,
+            DontDeletePimpl,
+            DeclaredRimpl
+        >
+        Type;
+
+
+        typedef PimplLife
+        <
+            Type,
+            Type*,
+            AutoDeletePimpl
+        >
+        Life;
+
+
+
+        typedef PtrImpl
+        <
+            Impl<T>,
+            Impl<T>*,
+            AutoDeletePimpl,
+            InheritedRimpl
+        >
+        Owner;
+
+    };
+    
+
+}
+
+#endif

include/loki/PimplDef.h

@@ -0,0 +1,70 @@
+////////////////////////////////////////////////////////////////////////////////
+// The Loki Library
+// Copyright (c) 2006 Peter Kümmel
+// Permission to use, copy, modify, distribute and sell this software for any 
+//     purpose is hereby granted without fee, provided that the above copyright 
+//     notice appear in all copies and that both that copyright notice and this 
+//     permission notice appear in supporting documentation.
+// The author makes no representations about the 
+//     suitability of this software for any purpose. It is provided "as is" 
+//     without express or implied warranty.
+////////////////////////////////////////////////////////////////////////////////
+#ifndef LOKI_PIMPLDEF_H
+#define LOKI_PIMPLDEF_H
+
+#include <loki/Pimpl.h>
+
+namespace Loki
+{
+    template
+    <
+        class Impl,
+        class Ptr,
+        template<class> class Del
+    >
+    inline 
+    PimplLife<Impl,Ptr,Del>::PimplLife()    //: ptr(Ptr()) this owerwrites the pointer to PtrImpl
+    {}                                        // when using DeclaredRimpl!!
+
+    template
+    <
+        class Impl,
+        class Ptr,
+        template<class> class Del
+    >
+    inline 
+    PimplLife<Impl,Ptr,Del>::~PimplLife()
+    {
+        Del<Ptr>::Destroy( ptr );
+    }
+
+    template
+    <
+        class Impl,
+        class Ptr,
+        template<class> class Del
+    >
+    template<class T>
+    inline 
+    PimplLife<Impl,Ptr,Del>::operator T&()
+    {
+        ptr = Ptr( new Impl );
+        return *ptr;
+    }
+
+    template
+    <
+        class Impl,
+        class Ptr,
+        template<class> class Del
+    >
+    inline
+    Ptr
+    PimplLife<Impl,Ptr,Del>::Create()
+    {
+        ptr = Ptr( new Impl );
+        return ptr;
+    }
+}
+
+#endif