Added SizeExtensions class

Author: Sergio0694

Microsoft.Toolkit.Uwp/Extensions/SizeExtensions.cs

@@ -0,0 +1,57 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Diagnostics.Contracts;
+using System.Runtime.CompilerServices;
+using Point = Windows.Foundation.Point;
+using Rect = Windows.Foundation.Rect;
+using Size = Windows.Foundation.Size;
+
+namespace Microsoft.Toolkit.Uwp.Extensions
+{
+    /// <summary>
+    /// Extensions for the <see cref="Size"/> type.
+    /// </summary>
+    public static class SizeExtensions
+    {
+        /// <summary>
+        /// Creates a new <see cref="Rect"/> of the specified size, starting at the origin.
+        /// </summary>
+        /// <param name="size">The input <see cref="Size"/> value to convert.</param>
+        /// <returns>A <see cref="Rect"/> value of the specified size, starting at the origin.</returns>
+        [Pure]
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static Rect ToRect(this Size size)
+        {
+            return new Rect(0, 0, size.Width, size.Height);
+        }
+
+        /// <summary>
+        /// Creates a new <see cref="Rect"/> of the specified size, starting at the given coordinates.
+        /// </summary>
+        /// <param name="size">The input <see cref="Size"/> value to convert.</param>
+        /// <param name="x">The horizontal offset.</param>
+        /// <param name="y">The vertical offset.</param>
+        /// <returns>A <see cref="Rect"/> value of the specified size, starting at the given coordinates.</returns>
+        [Pure]
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static Rect ToRect(this Size size, double x, double y)
+        {
+            return new Rect(x, y, size.Width, size.Height);
+        }
+
+        /// <summary>
+        /// Creates a new <see cref="Rect"/> of the specified size, starting at the given position.
+        /// </summary>
+        /// <param name="size">The input <see cref="Size"/> value to convert.</param>
+        /// <param name="point">The starting position to use.</param>
+        /// <returns>A <see cref="Rect"/> value of the specified size, starting at the given position.</returns>
+        [Pure]
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static Rect ToRect(this Size size, Point point)
+        {
+            return new Rect(point, size);
+        }
+    }
+}