Added RefEnumerator.Count, Reset and indexer

Core/RefEnumerator.cs

@@ -1,47 +1,53 @@
-using System.Runtime.InteropServices;
-
-namespace Vanara.PInvoke
+namespace Vanara.PInvoke
 {
-    /// <summary>
-    /// Enumerator with zero copy access using ref.
-    /// </summary>
-    public unsafe ref struct RefEnumerator<T> where T : unmanaged
-    {
-        private T* _arrayPtr;
-        private readonly int _count;
-        private int _index;
+	/// <summary>Enumerator with zero copy access using ref.</summary>
+	/// <typeparam name="T">The structure type.</typeparam>
+	public unsafe ref struct RefEnumerator<T> where T : unmanaged
+	{
+		private T* _arrayPtr, basePtr;
+		private int _index;
 
-        /// <summary>
-        /// Create RefEnumerator.
-        /// </summary>
-        /// <param name="arrayPtr">Pointer to unmanaged array</param>
-        /// <param name="count">Number of elements in the <paramref name="arrayPtr"/></param>
-        public RefEnumerator(T* arrayPtr, int count)
-        {
-            _arrayPtr = arrayPtr;
-            _count = count;
-            _index = -1;
-        }
+		/// <summary>Create RefEnumerator.</summary>
+		/// <param name="arrayPtr">Pointer to unmanaged array</param>
+		/// <param name="count">Number of elements in the <paramref name="arrayPtr"/></param>
+		public RefEnumerator(T* arrayPtr, int count)
+		{
+			_arrayPtr = basePtr = arrayPtr;
+			Count = count;
+			_index = -1;
+		}
 
-        /// <summary>
-        /// Move to next element.
-        /// </summary>
-        public bool MoveNext()
-        {
-            int index = _index + 1;
-            if (index < _count)
-            {
-                _index = index;
-                _arrayPtr++;
-                return true;
-            }
+		/// <summary>Gets the number of elements available.</summary>
+		/// <value>The number of elements available.</value>
+		public int Count { get; private set; }
 
-            return false;
-        }
+		/// <summary>Return current element.</summary>
+		public ref T Current => ref *_arrayPtr;
 
-        /// <summary>
-        /// Return current element.
-        /// </summary>
-        public ref T Current => ref *_arrayPtr;
-    }
-}
+		/// <summary>Gets the <typeparamref name="T"/> at the specified index.</summary>
+		/// <value>The <typeparamref name="T"/>.</value>
+		/// <param name="index">The index.</param>
+		/// <returns>A reference to <typeparamref name="T"/>.</returns>
+		public ref T this[int index] => ref _arrayPtr[index];
+
+		/// <summary>Move to next element.</summary>
+		public bool MoveNext()
+		{
+			int index = _index + 1;
+			if (index < Count)
+			{
+				_index = index;
+				_arrayPtr++;
+				return true;
+			}
+			return false;
+		}
+
+		/// <summary>Resets this iterator.</summary>
+		public void Reset()
+		{
+			_arrayPtr = basePtr;
+			_index = -1;
+		}
+	}
+}