1 files changed, 118 insertions, 0 deletions
diff --git a/src/Platform/ForEach.h b/src/Platform/ForEach.h
new file mode 100644
index 00000000..786ff56b
--- /dev/null
+++ b/src/Platform/ForEach.h
@@ -0,0 +1,118 @@
+/*
+ Copyright (c) 2008 TrueCrypt Developers Association. All rights reserved.
+
+ Governed by the TrueCrypt License 3.0 the full text of which is contained in
+ the file License.txt included in TrueCrypt binary and source code distribution
+ packages.
+*/
+
+#ifndef TC_HEADER_Platform_ForEach
+#define TC_HEADER_Platform_ForEach
+
+namespace TrueCrypt
+{
+	class ForEach
+	{
+	public:
+		struct Container
+		{
+			Container () : InnerContinue (true), InnerEndCondition (false) { }
+			virtual ~Container () { }
+
+			void Continue () const { InnerContinue = true; }
+			bool InnerIsNotEnd () const { return InnerEndCondition = !InnerEndCondition; }
+			virtual bool IsNotEnd () const = 0;
+			virtual void Next () const = 0;
+
+			mutable bool InnerContinue;
+			mutable bool InnerEndCondition;
+		};
+
+	protected:
+		template <class T>
+		struct ContainerForward : Container
+		{
+			ContainerForward (const T &container)
+				: ContainerCopy (container), EndIterator (ContainerCopy.end()), Iterator (ContainerCopy.begin()) { }
+
+			virtual bool IsNotEnd () const { bool r = InnerContinue && Iterator != EndIterator; InnerContinue = false; return r; }
+			virtual void Next () const { ++Iterator; }
+
+			const T ContainerCopy;	// Support for temporary objects
+			typename T::const_iterator EndIterator;
+			mutable typename T::const_iterator Iterator;
+
+		private:
+			ContainerForward &operator= (const ContainerForward &);
+		};
+
+		template <class T>
+		struct ContainerReverse : Container
+		{
+			ContainerReverse (const T &container)
+				: ContainerCopy (container), EndIterator (ContainerCopy.rend()), Iterator (ContainerCopy.rbegin()) { }
+
+			virtual bool IsNotEnd () const { bool r = InnerContinue && Iterator != EndIterator; InnerContinue = false; return r; }
+			virtual void Next () const { ++Iterator; }
+
+			const T ContainerCopy;
+			typename T::const_reverse_iterator EndIterator;
+			mutable typename T::const_reverse_iterator Iterator;
+			
+		private:
+			ContainerReverse &operator= (const ContainerReverse &);
+		};
+
+	public:
+		template <class T>
+		static ContainerForward <T> GetContainerForward (const T &container)
+		{
+			return ContainerForward <T> (container);
+		}
+
+		template <class T>
+		static ContainerReverse <T> GetContainerReverse (const T &container)
+		{
+			return ContainerReverse <T> (container);
+		}
+
+	protected:
+		template <class T>
+		struct TypeWrapper { };
+
+	public:
+		template <class T>
+		static TypeWrapper <T> ToTypeWrapper (const T &x) { return TypeWrapper <T> (); }
+
+		struct TypeWrapperDummy
+		{
+			template <class T>
+			operator TypeWrapper <T> () const { return TypeWrapper <T> (); }
+		};
+
+		template <class T>
+		static const ContainerForward <T> &GetContainerForward (const Container &forEachContainer, const TypeWrapper <T> &)
+		{
+			return static_cast <const ContainerForward <T> &> (forEachContainer);
+		}
+
+		template <class T>
+		static const ContainerReverse <T> &GetContainerReverse (const Container &forEachContainer, const TypeWrapper <T> &)
+		{
+			return static_cast <const ContainerReverse <T> &> (forEachContainer);
+		}
+	};
+}
+
+
+#define FOREACH_TEMPLATE(dereference,listType,variable,listInstance) \
+	for (const ForEach::Container &forEachContainer = ForEach::GetContainer##listType (listInstance); forEachContainer.IsNotEnd(); forEachContainer.Next()) \
+		for (variable = dereference(ForEach::GetContainer##listType (forEachContainer, (true ? ForEach::TypeWrapperDummy() : ForEach::ToTypeWrapper (listInstance))).Iterator); forEachContainer.InnerIsNotEnd(); forEachContainer.Continue())
+
+#define foreach(variable,listInstance) FOREACH_TEMPLATE(*, Forward, variable, listInstance)
+#define foreach_ref(variable,listInstance) FOREACH_TEMPLATE(**, Forward, variable, listInstance)
+#define foreach_reverse(variable,listInstance) FOREACH_TEMPLATE(*, Reverse, variable, listInstance)
+#define foreach_reverse_ref(variable,listInstance) FOREACH_TEMPLATE(**, Reverse, variable, listInstance)
+
+
+#endif // TC_HEADER_Platform_ForEach