refactor(iterator): add iterator example class and split iterator library into multiple files

Redcraft.Utility/Source/Public/Iterator/ForwardIterator.h

@@ -0,0 +1,63 @@
+#pragma once
+
+#include "CoreTypes.h"
+#include "Iterator/Utility.h"
+#include "Iterator/Sentinel.h"
+#include "TypeTraits/TypeTraits.h"
+
+NAMESPACE_REDCRAFT_BEGIN
+NAMESPACE_MODULE_BEGIN(Redcraft)
+NAMESPACE_MODULE_BEGIN(Utility)
+
+#if PLATFORM_COMPILER_GCC
+#	pragma GCC diagnostic push
+#	pragma GCC diagnostic ignored "-Wnon-template-friend"
+#endif
+
+/** A concept specifies a type is an input iterator. It is input iterator, incrementable, and sentinel for itself. */
+template <typename I>
+concept CForwardIterator = CInputIterator<I> && CIncrementable<I> && CSentinelFor<I, I>;
+
+/** This is an example of a forward iterator, indicate the traits that define a forward iterator. */
+template <CReference T>
+struct IForwardIterator /* : IInputIterator<T>, IIncrementable, ISentinelFor<I> */
+{
+	/** The element type of the indirectly readable type. See 'IIndirectlyReadable'. */
+	using ElementType = TRemoveCVRef<T>;
+
+	/** Default constructor. See 'IIncrementable' and 'ISentinelFor'. */
+	IForwardIterator();
+
+	/** Copy constructor. See 'IIncrementable' and 'ISentinelFor'. */
+	IForwardIterator(const IForwardIterator&);
+
+	/** Copy assignment operator. See 'IIncrementable' and 'ISentinelFor'. */
+	IForwardIterator* operator=(const IForwardIterator&);
+
+	/** Equality operator. See 'IIncrementable' and 'ISentinelFor'. */
+	friend bool operator==(const IForwardIterator&, const IForwardIterator&);
+
+	/**
+	 * Indirectly read the element from the indirectly readable type. See 'IIndirectlyReadable'.
+	 * Indirectly write the element if the type is also an indirectly writable type. See 'IIndirectlyWritable'.
+	 */
+	T operator*() const;
+
+	/** Pre-increment operator. See 'IWeaklyIncrementable'. */
+	IForwardIterator& operator++();
+
+	/** Post-increment operator. See 'IIncrementable'. */
+	IForwardIterator operator++(int);
+};
+
+// Use 'IForwardIterator<int>' represents a forward iterator.
+static_assert(CForwardIterator<IForwardIterator<int&>>);
+static_assert( COutputIterator<IForwardIterator<int&>, int>);
+
+#if PLATFORM_COMPILER_GCC
+#	pragma GCC diagnostic pop
+#endif
+
+NAMESPACE_MODULE_END(Utility)
+NAMESPACE_MODULE_END(Redcraft)
+NAMESPACE_REDCRAFT_END