Adding a type vector to replace type cells.

src/third_party/loki/TypeManip.h

+////////////////////////////////////////////////////////////////////////////////
+// The Loki Library
+// Copyright (c) 2001 by Andrei Alexandrescu
+// This code accompanies the book:
+// Alexandrescu, Andrei. "Modern C++ Design: Generic Programming and Design 
+//     Patterns Applied". Copyright (c) 2001. Addison-Wesley.
+// 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 or Addison-Welsey Longman make no representations about the 
+//     suitability of this software for any purpose. It is provided "as is" 
+//     without express or implied warranty.
+////////////////////////////////////////////////////////////////////////////////
+#ifndef LOKI_TYPEMANIP_INC_
+#define LOKI_TYPEMANIP_INC_
+
+// $Id: TypeManip.h 749 2006-10-17 19:49:26Z syntheticpp $
+
+
+namespace Loki
+{
+////////////////////////////////////////////////////////////////////////////////
+// class template Int2Type
+// Converts each integral constant into a unique type
+// Invocation: Int2Type<v> where v is a compile-time constant integral
+// Defines 'value', an enum that evaluates to v
+////////////////////////////////////////////////////////////////////////////////
+
+    template <int v>
+    struct Int2Type
+    {
+        enum { value = v };
+    };
+    
+////////////////////////////////////////////////////////////////////////////////
+// class template Type2Type
+// Converts each type into a unique, insipid type
+// Invocation Type2Type<T> where T is a type
+// Defines the type OriginalType which maps back to T
+////////////////////////////////////////////////////////////////////////////////
+
+    template <typename T>
+    struct Type2Type
+    {
+        typedef T OriginalType;
+    };
+    
+////////////////////////////////////////////////////////////////////////////////
+// class template Select
+// Selects one of two types based upon a boolean constant
+// Invocation: Select<flag, T, U>::Result
+// where:
+// flag is a compile-time boolean constant
+// T and U are types
+// Result evaluates to T if flag is true, and to U otherwise.
+////////////////////////////////////////////////////////////////////////////////
+
+    template <bool flag, typename T, typename U>
+    struct Select
+    {
+        typedef T Result;
+    };
+    template <typename T, typename U>
+    struct Select<false, T, U>
+    {
+        typedef U Result;
+    };
+    
+////////////////////////////////////////////////////////////////////////////////
+// class template IsSameType
+// Return true iff two given types are the same
+// Invocation: SameType<T, U>::value
+// where:
+// T and U are types
+// Result evaluates to true iff U == T (types equal)
+////////////////////////////////////////////////////////////////////////////////
+
+    template <typename T, typename U>
+    struct IsSameType
+    {
+        enum { value = false };
+    };
+    
+    template <typename T>
+    struct IsSameType<T,T>
+    {
+        enum { value = true };
+    };
+
+////////////////////////////////////////////////////////////////////////////////
+// Helper types Small and Big - guarantee that sizeof(Small) < sizeof(Big)
+////////////////////////////////////////////////////////////////////////////////
+
+    namespace Private
+    {
+        template <class T, class U>
+        struct ConversionHelper
+        {
+            typedef char Small;
+            struct Big { char dummy[2]; };
+            static Big   Test(...);
+            static Small Test(U);
+            static T MakeT();
+        };
+    }
+
+////////////////////////////////////////////////////////////////////////////////
+// class template Conversion
+// Figures out the conversion relationships between two types
+// Invocations (T and U are types):
+// a) Conversion<T, U>::exists
+// returns (at compile time) true if there is an implicit conversion from T
+// to U (example: Derived to Base)
+// b) Conversion<T, U>::exists2Way
+// returns (at compile time) true if there are both conversions from T
+// to U and from U to T (example: int to char and back)
+// c) Conversion<T, U>::sameType
+// returns (at compile time) true if T and U represent the same type
+//
+// Caveat: might not work if T and U are in a private inheritance hierarchy.
+////////////////////////////////////////////////////////////////////////////////
+
+    template <class T, class U>
+    struct Conversion
+    {
+        typedef Private::ConversionHelper<T, U> H;
+#ifndef __MWERKS__
+        enum { exists = sizeof(typename H::Small) == sizeof((H::Test(H::MakeT()))) };
+#else
+        enum { exists = false };
+#endif
+        enum { exists2Way = exists && Conversion<U, T>::exists };
+        enum { sameType = false };
+    };
+    
+    template <class T>
+    struct Conversion<T, T>    
+    {
+        enum { exists = 1, exists2Way = 1, sameType = 1 };
+    };
+    
+    template <class T>
+    struct Conversion<void, T>    
+    {
+        enum { exists = 0, exists2Way = 0, sameType = 0 };
+    };
+    
+    template <class T>
+    struct Conversion<T, void>    
+    {
+        enum { exists = 0, exists2Way = 0, sameType = 0 };
+    };
+    
+    template <>
+    struct Conversion<void, void>    
+    {
+    public:
+        enum { exists = 1, exists2Way = 1, sameType = 1 };
+    };
+
+////////////////////////////////////////////////////////////////////////////////
+// class template SuperSubclass
+// Invocation: SuperSubclass<B, D>::value where B and D are types. 
+// Returns true if B is a public base of D, or if B and D are aliases of the 
+// same type.
+//
+// Caveat: might not work if T and U are in a private inheritance hierarchy.
+////////////////////////////////////////////////////////////////////////////////
+
+template <class T, class U>
+struct SuperSubclass
+{
+    enum { value = (::Loki::Conversion<const volatile U*, const volatile T*>::exists &&
+                  !::Loki::Conversion<const volatile T*, const volatile void*>::sameType) };
+      
+    // Dummy enum to make sure that both classes are fully defined.
+    enum{ dontUseWithIncompleteTypes = ( sizeof (T) == sizeof (U) ) };
+};
+
+template <>
+struct SuperSubclass<void, void> 
+{
+    enum { value = false };
+};
+
+template <class U>
+struct SuperSubclass<void, U> 
+{
+    enum { value = (::Loki::Conversion<const volatile U*, const volatile void*>::exists &&
+                  !::Loki::Conversion<const volatile void*, const volatile void*>::sameType) };
+      
+    // Dummy enum to make sure that both classes are fully defined.
+    enum{ dontUseWithIncompleteTypes = ( 0 == sizeof (U) ) };
+};
+
+template <class T>
+struct SuperSubclass<T, void> 
+{
+    enum { value = (::Loki::Conversion<const volatile void*, const volatile T*>::exists &&
+                  !::Loki::Conversion<const volatile T*, const volatile void*>::sameType) };
+      
+    // Dummy enum to make sure that both classes are fully defined.
+    enum{ dontUseWithIncompleteTypes = ( sizeof (T) == 0 ) };
+};
+
+////////////////////////////////////////////////////////////////////////////////
+// class template SuperSubclassStrict
+// Invocation: SuperSubclassStrict<B, D>::value where B and D are types. 
+// Returns true if B is a public base of D.
+//
+// Caveat: might not work if T and U are in a private inheritance hierarchy.
+////////////////////////////////////////////////////////////////////////////////
+
+template<class T,class U>
+struct SuperSubclassStrict
+{
+    enum { value = (::Loki::Conversion<const volatile U*, const volatile T*>::exists &&
+                 !::Loki::Conversion<const volatile T*, const volatile void*>::sameType &&
+                 !::Loki::Conversion<const volatile T*, const volatile U*>::sameType) };
+    
+    // Dummy enum to make sure that both classes are fully defined.
+    enum{ dontUseWithIncompleteTypes = ( sizeof (T) == sizeof (U) ) };
+};
+
+template<>
+struct SuperSubclassStrict<void, void> 
+{
+    enum { value = false };
+};
+
+template<class U>
+struct SuperSubclassStrict<void, U> 
+{
+    enum { value = (::Loki::Conversion<const volatile U*, const volatile void*>::exists &&
+                 !::Loki::Conversion<const volatile void*, const volatile void*>::sameType &&
+                 !::Loki::Conversion<const volatile void*, const volatile U*>::sameType) };
+    
+    // Dummy enum to make sure that both classes are fully defined.
+    enum{ dontUseWithIncompleteTypes = ( 0 == sizeof (U) ) };
+};
+
+template<class T>
+struct SuperSubclassStrict<T, void> 
+{
+    enum { value = (::Loki::Conversion<const volatile void*, const volatile T*>::exists &&
+                 !::Loki::Conversion<const volatile T*, const volatile void*>::sameType &&
+                 !::Loki::Conversion<const volatile T*, const volatile void*>::sameType) };
+    
+    // Dummy enum to make sure that both classes are fully defined.
+    enum{ dontUseWithIncompleteTypes = ( sizeof (T) == 0 ) };
+};
+
+
+}   // namespace Loki
+
+////////////////////////////////////////////////////////////////////////////////
+// macro SUPERSUBCLASS
+// Invocation: SUPERSUBCLASS(B, D) where B and D are types. 
+// Returns true if B is a public base of D, or if B and D are aliases of the 
+// same type.
+//
+// Caveat: might not work if T and U are in a private inheritance hierarchy.
+// Deprecated: Use SuperSubclass class template instead.
+////////////////////////////////////////////////////////////////////////////////
+
+#define LOKI_SUPERSUBCLASS(T, U) \
+    ::Loki::SuperSubclass<T,U>::value
+
+////////////////////////////////////////////////////////////////////////////////
+// macro SUPERSUBCLASS_STRICT
+// Invocation: SUPERSUBCLASS(B, D) where B and D are types. 
+// Returns true if B is a public base of D.
+//
+// Caveat: might not work if T and U are in a private inheritance hierarchy.
+// Deprecated: Use SuperSubclassStrict class template instead.
+////////////////////////////////////////////////////////////////////////////////
+
+#define LOKI_SUPERSUBCLASS_STRICT(T, U) \
+    ::Loki::SuperSubclassStrict<T,U>::value
+
+
+#endif // end file guardian