Added possibility to clone an existing ExaArray.

Closes thorsten/ExaArray#2 (comment)

ExaArray/ExaArray1D.Factories.cs

@@ -0,0 +1,35 @@
+using System;
+
+namespace Exa
+{
+    public partial class ExaArray1D<T>
+    {
+        /// <summary>
+        /// Creates a new ExaArray1D from another. 
+        /// </summary>
+        /// <remarks>
+        /// When <c>T</c> is a value type, data gets copied as values. When <c>T</c> is a reference type, the pointers
+        /// to the original objects are copied. Thus, this factory method does not create a deep copy.
+        ///
+        /// Performance: O(n)
+        /// </remarks>
+        /// <param name="other">The instance from which the new instance is to be created.</param>
+        /// <returns>The new instance</returns>
+        public static ExaArray1D<T> CreateFrom(ExaArray1D<T> other)
+        {
+            var next = new ExaArray1D<T>(other.OptimizationStrategy)
+            {
+                Length = other.Length,
+                chunks = new T[other.chunks.Length][]
+            };
+            
+            for (var n = 0; n < other.chunks.Length; n++)
+            {
+                next.chunks[n] =  new T[other.chunks[n].Length];
+                Array.Copy(other.chunks[n], next.chunks[n], other.chunks[n].Length);
+            }
+            
+            return next;
+        }
+    }
+}

ExaArray/ExaArray1D.cs

@@ -8,7 +8,7 @@ namespace Exa
     /// to 4.6 quintillion (4,607,183,514,018,780,000) or 4.6 exa elements. 
     /// </summary>
     /// <typeparam name="T">The desired type to use, e.g. byte, int, etc.</typeparam>
-    public sealed class ExaArray1D<T>
+    public sealed partial class ExaArray1D<T>
     {
         /// <summary>
         /// Unfortunately, this seems to be the maximal number of entries an

ExaArrayTests/ExaArray1DTests.cs

@@ -180,7 +180,7 @@ namespace ExaArrayTests
             }
 
             [Test]
-            [Category("normal")]
+            [Category("intensive")]
             public void CountingHugeSize01()
             {
                 var exaA = new ExaArray1D<byte>();
@@ -194,6 +194,114 @@ namespace ExaArrayTests
                 });
             }
 
+            [Test]
+            [Category("normal")]
+            [Category("cover")]
+            public void CreateFrom001()
+            {
+                var exPerf = new ExaArray1D<byte>(Strategy.MAX_PERFORMANCE);
+                exPerf.Extend(2);
+                exPerf[0] = 0x01;
+                exPerf[1] = 0x02;
+
+                var next = ExaArray1D<byte>.CreateFrom(exPerf);
+                Assert.That(next.Length, Is.EqualTo(exPerf.Length));
+                Assert.That(next.OptimizationStrategy, Is.EqualTo(exPerf.OptimizationStrategy));
+                Assert.That(next.Items(), Is.EquivalentTo(exPerf.Items()));
+
+                exPerf = null;
+                next = null;
+                
+                var exElem = new ExaArray1D<byte>(Strategy.MAX_ELEMENTS);
+                exElem.Extend(2);
+                exElem[0] = 0x03;
+                exElem[1] = 0x04;
+
+                next = ExaArray1D<byte>.CreateFrom(exElem);
+                Assert.That(next.Length, Is.EqualTo(exElem.Length));
+                Assert.That(next.OptimizationStrategy, Is.EqualTo(exElem.OptimizationStrategy));
+                Assert.That(next.Items(), Is.EquivalentTo(exElem.Items()));
+            }
+            
+            [Test]
+            [Category("normal")]
+            [Category("cover")]
+            public void CreateFrom002Objects()
+            {
+                var exPerf = new ExaArray1D<object>(Strategy.MAX_PERFORMANCE);
+                exPerf.Extend(2);
+                exPerf[0] = new object();
+                exPerf[1] = new object();
+
+                var next = ExaArray1D<object>.CreateFrom(exPerf);
+                Assert.That(next.Length, Is.EqualTo(exPerf.Length));
+                Assert.That(next.OptimizationStrategy, Is.EqualTo(exPerf.OptimizationStrategy));
+                Assert.That(next[0], Is.SameAs(exPerf[0]));
+                Assert.That(next[1], Is.SameAs(exPerf[1]));
+                Assert.That(next[0], Is.Not.SameAs(next[1]));
+
+                exPerf = null;
+                next = null;
+                
+                var exElem = new ExaArray1D<object>(Strategy.MAX_ELEMENTS);
+                exElem.Extend(2);
+                exElem[0] = new object();
+                exElem[1] = new object();
+
+                next = ExaArray1D<object>.CreateFrom(exElem);
+                Assert.That(next.Length, Is.EqualTo(exElem.Length));
+                Assert.That(next.OptimizationStrategy, Is.EqualTo(exElem.OptimizationStrategy));
+                Assert.That(next[0], Is.SameAs(exElem[0]));
+                Assert.That(next[1], Is.SameAs(exElem[1]));
+                Assert.That(next[0], Is.Not.SameAs(next[1]));
+            }
+            
+            [Test]
+            [Category("normal")]
+            [Category("cover")]
+            public void CreateFrom003()
+            {
+                var exPerf = new ExaArray1D<byte>(Strategy.MAX_PERFORMANCE);
+                exPerf.Extend(5_000_000_000); // more than one chunk
+                
+                var next = ExaArray1D<byte>.CreateFrom(exPerf);
+                Assert.That(next.Length, Is.EqualTo(exPerf.Length));
+                Assert.DoesNotThrow(() =>
+                {
+                    next[4_999_999_999] = 0xab;
+                });
+
+                exPerf = null;
+                next = null;
+                
+                var exElem = new ExaArray1D<byte>(Strategy.MAX_ELEMENTS);
+                exElem.Extend(5_000_000_000);
+                
+                next = ExaArray1D<byte>.CreateFrom(exElem);
+                Assert.That(next.Length, Is.EqualTo(exElem.Length));
+                Assert.DoesNotThrow(() =>
+                {
+                    next[4_999_999_999] = 0xab;
+                });
+            }
+            
+            [Test]
+            [Category("normal")]
+            [Category("cover")]
+            public void CreateFrom004()
+            {
+                var exPerf = new ExaArray1D<byte>(Strategy.MAX_PERFORMANCE);
+                var next = ExaArray1D<byte>.CreateFrom(exPerf);
+                Assert.That(next.Length, Is.EqualTo(0));
+                
+                exPerf = null;
+                next = null;
+                
+                var exElem = new ExaArray1D<byte>(Strategy.MAX_ELEMENTS);
+                next = ExaArray1D<byte>.CreateFrom(exElem);
+                Assert.That(next.Length, Is.EqualTo(0));
+            }
+
             [Test]
             [Category("intensive")]
             public void Adding5Billion01()