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

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

@@ -0,0 +1,75 @@
+#pragma once
+
+#include "CoreTypes.h"
+#include "Iterator/Utility.h"
+#include "Iterator/Sentinel.h"
+#include "Iterator/ForwardIterator.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 a bidirectional iterator. Add the decrement operator to the forward iterator. */
+template <typename I>
+concept CBidirectionalIterator = CForwardIterator<I>
+	&& requires(I Iter) {
+		{ --Iter } -> CSameAs<I&>;
+		{ Iter-- } -> CSameAs<I >;
+	};
+
+/**
+ * This is an example of a bidirectional iterator, indicate the traits that define a bidirectional iterator.
+ * Regardless of the order in which the increment and decrement operators are applied,
+ * the result is always the same if both operations are performed the same number of times.
+ */
+template <CReference T>
+struct IBidirectionalIterator /* : IForwardIterator<T> */
+{
+	/** The element type of the indirectly readable type. See 'IIndirectlyReadable'. */
+	using ElementType = TRemoveCVRef<T>;
+
+	/** Default constructor. See 'IIncrementable' and 'ISentinelFor'. */
+	IBidirectionalIterator();
+
+	/** Copy constructor. See 'IIncrementable' and 'ISentinelFor'. */
+	IBidirectionalIterator(const IBidirectionalIterator&);
+
+	/** Copy assignment operator. See 'IIncrementable' and 'ISentinelFor'. */
+	IBidirectionalIterator* operator=(const IBidirectionalIterator&);
+
+	/** Equality operator. See 'IIncrementable' and 'ISentinelFor'. */
+	friend bool operator==(const IBidirectionalIterator&, const IBidirectionalIterator&);
+
+	/** Dereference operator. See 'IForwardIterator'. */
+	T operator*() const;
+
+	/** Pre-increment operator. See 'IWeaklyIncrementable'. */
+	IBidirectionalIterator& operator++();
+
+	/** Pre-decrement operator. */
+	IBidirectionalIterator& operator--();
+
+	/** Post-increment operator. See 'IIncrementable'. */
+	IBidirectionalIterator operator++(int);
+
+	/** Post-decrement operator. */
+	IBidirectionalIterator operator--(int);
+};
+
+// Use 'IBidirectionalIterator<int>' represents a bidirectional iterator.
+static_assert(CBidirectionalIterator<IBidirectionalIterator<int&>>);
+static_assert(       COutputIterator<IBidirectionalIterator<int&>, int>);
+
+#if PLATFORM_COMPILER_GCC
+#	pragma GCC diagnostic pop
+#endif
+
+NAMESPACE_MODULE_END(Utility)
+NAMESPACE_MODULE_END(Redcraft)
+NAMESPACE_REDCRAFT_END