Add implicit operator to Span<T> to allow conversion from array (#265)

Author: josesimoes

Tests/NFUnitTestTypes/UnitTestsReadOnlySpanByte.cs

@@ -365,6 +365,16 @@ public void ConstructorsOfAllKindsTests()
 
             Assert.AreEqual(span.Length, 8, $"ReadOnlySpan should have length of 8");
             Assert.IsFalse(span.IsEmpty, "ReadOnlySpan should NOT be IsEmpty");
+
+            // ReadOnlySpan from array initializer
+            span = new byte[] { 0xAA, 0xBB, 0xCC, 0xDD };
+
+            Assert.AreEqual(span.Length, 4, "ReadOnlySpan from array initializer should have length of 4");
+            Assert.IsFalse(span.IsEmpty, "ReadOnlySpan from array initializer should NOT be IsEmpty");
+            Assert.AreEqual(span[0], (byte)0xAA, "First element should be 0xAA");
+            Assert.AreEqual(span[1], (byte)0xBB, "Second element should be 0xBB");
+            Assert.AreEqual(span[2], (byte)0xCC, "Third element should be 0xCC");
+            Assert.AreEqual(span[3], (byte)0xDD, "Fourth element should be 0xDD");
         }
 
         [TestMethod]

Tests/NFUnitTestTypes/UnitTestsSpanByte.cs

@@ -362,6 +362,17 @@ public void ConstructorsOfAllKindsTests()
 
             Assert.AreEqual(span.Length, 8, $"SpanByte should have length of 8");
             Assert.IsFalse(span.IsEmpty, "SpanByte should NOT be IsEmpty");
+
+            // Span<byte> from array initializer
+            span = new byte[] { 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19 };
+
+            Assert.AreEqual(span.Length, 10, $"SpanByte should have length of 10");
+            Assert.IsFalse(span.IsEmpty, "Span<byte> should NOT be IsEmpty");
+
+            Assert.AreEqual(span[0], (byte)0x10, "First element must be value 0x10");
+            Assert.AreEqual(span[1], (byte)0x11, "Second element must be value 0x11");
+            Assert.AreEqual(span[5], (byte)0x15, "Sixth element must be value 0x15");
+            Assert.AreEqual(span[9], (byte)0x19, "Last element must be value 0x19");
         }
 
         [TestMethod]

nanoFramework.CoreLibrary/System/AssemblyInfo.cs

@@ -10,4 +10,4 @@
 [assembly: AssemblyProduct(".NET nanoFramework mscorlib")]
 [assembly: AssemblyCopyright("Copyright (c) .NET Foundation and Contributors")]
 
-[assembly: AssemblyNativeVersion("100.22.0.2")]
+[assembly: AssemblyNativeVersion("100.22.0.3")]

nanoFramework.CoreLibrary/System/Span.cs

@@ -164,6 +164,12 @@ public ref T this[int index]
         /// </remarks>
         public static bool operator !=(Span<T> left, Span<T> right) => !(left == right);
 
+        /// <summary>
+        /// Defines an implicit conversion of an array to a <see cref="Span{T}"/>
+        /// </summary>
+        /// <param name="array">The array to convert to a <see cref="Span{T}"/>.</param>
+        public static implicit operator Span<T>(T[]? array) => new Span<T>(array);
+
         /// <summary>
         /// Returns an empty <see cref="Span{T}"/> object.
         /// </summary>