Spans.cs: Allow empty spans.

samuel-lucas6 · Aug 29, 2022 · 3d68552 · 3d68552
1 parent f5d6729
commit 3d68552
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Showing 2 changed files with 23 additions and 20 deletions.
diff --git a/src/Geralt.Tests/SpansTests.cs b/src/Geralt.Tests/SpansTests.cs
@@ -70,4 +70,27 @@ public void Concat_SixSpans()
         Span<byte> expected = Concat(Array1, Array2, Array3, Array4, Array5, Array6);
         Assert.IsTrue(concatenated.SequenceEqual(expected));
     }
+
+    [TestMethod]
+    public void Concat_TwoSpansBothEmpty()
+    {
+        Span<byte> empty1 = Span<byte>.Empty;
+        Span<byte> empty2 = Span<byte>.Empty;
+        Span<byte> concatenated = stackalloc byte[empty1.Length + empty2.Length];
+        Spans.Concat(concatenated, empty1, empty2);
+        Span<byte> expected = Concat(empty1.ToArray(), empty2.ToArray());
+        Assert.IsTrue(concatenated.SequenceEqual(expected));
+    }
+
+    [TestMethod]
+    public void Concat_TwoSpansOneEmpty()
+    {
+        Span<byte> empty = Span<byte>.Empty;
+        Span<byte> concatenated = stackalloc byte[empty.Length + Array2.Length];
+        Spans.Concat(concatenated, empty, Array2);
+        Span<byte> expected = Concat(empty.ToArray(), Array2);
+        Assert.IsTrue(concatenated.SequenceEqual(expected));
+        Spans.Concat(concatenated, Array2, empty);
+        Assert.IsTrue(concatenated.SequenceEqual(expected));
+    }
 }
diff --git a/src/Geralt/Helpers/Spans.cs b/src/Geralt/Helpers/Spans.cs
@@ -7,8 +7,6 @@ public static void Concat(Span<byte> buffer, ReadOnlySpan<byte> a, ReadOnlySpan<
         checked
         {
             Validation.EqualToSize(nameof(buffer), buffer.Length, a.Length + b.Length);
-            Validation.NotEmpty(nameof(a), a.Length);
-            Validation.NotEmpty(nameof(b), b.Length);
             Validation.EqualToSize(nameof(a), a.Length, buffer.Length - b.Length);
             Validation.EqualToSize(nameof(b), b.Length, buffer.Length - a.Length);
             a.CopyTo(buffer.Slice(start: 0, a.Length));
@@ -21,9 +19,6 @@ public static void Concat(Span<byte> buffer, ReadOnlySpan<byte> a, ReadOnlySpan<
         checked
         {
             Validation.EqualToSize(nameof(buffer), buffer.Length, a.Length + b.Length + c.Length);
-            Validation.NotEmpty(nameof(a), a.Length);
-            Validation.NotEmpty(nameof(b), b.Length);
-            Validation.NotEmpty(nameof(c), c.Length);
             Validation.EqualToSize(nameof(a), a.Length, buffer.Length - b.Length - c.Length);
             Validation.EqualToSize(nameof(b), b.Length, buffer.Length - a.Length - c.Length);
             Validation.EqualToSize(nameof(c), c.Length, buffer.Length - a.Length - b.Length);
@@ -38,10 +33,6 @@ public static void Concat(Span<byte> buffer, ReadOnlySpan<byte> a, ReadOnlySpan<
         checked
         {
             Validation.EqualToSize(nameof(buffer), buffer.Length, a.Length + b.Length + c.Length + d.Length);
-            Validation.NotEmpty(nameof(a), a.Length);
-            Validation.NotEmpty(nameof(b), b.Length);
-            Validation.NotEmpty(nameof(c), c.Length);
-            Validation.NotEmpty(nameof(d), d.Length);
             Validation.EqualToSize(nameof(a), a.Length, buffer.Length - b.Length - c.Length - d.Length);
             Validation.EqualToSize(nameof(b), b.Length, buffer.Length - a.Length - c.Length - d.Length);
             Validation.EqualToSize(nameof(c), c.Length, buffer.Length - a.Length - b.Length - d.Length);
@@ -58,11 +49,6 @@ public static void Concat(Span<byte> buffer, ReadOnlySpan<byte> a, ReadOnlySpan<
         checked
         {
             Validation.EqualToSize(nameof(buffer), buffer.Length, a.Length + b.Length + c.Length + d.Length + e.Length);
-            Validation.NotEmpty(nameof(a), a.Length);
-            Validation.NotEmpty(nameof(b), b.Length);
-            Validation.NotEmpty(nameof(c), c.Length);
-            Validation.NotEmpty(nameof(d), d.Length);
-            Validation.NotEmpty(nameof(e), e.Length);
             Validation.EqualToSize(nameof(a), a.Length, buffer.Length - b.Length - c.Length - d.Length - e.Length);
             Validation.EqualToSize(nameof(b), b.Length, buffer.Length - a.Length - c.Length - d.Length - e.Length);
             Validation.EqualToSize(nameof(c), c.Length, buffer.Length - a.Length - b.Length - d.Length - e.Length);
@@ -81,12 +67,6 @@ public static void Concat(Span<byte> buffer, ReadOnlySpan<byte> a, ReadOnlySpan<
         checked
         {
             Validation.EqualToSize(nameof(buffer), buffer.Length, a.Length + b.Length + c.Length + d.Length + e.Length + f.Length);
-            Validation.NotEmpty(nameof(a), a.Length);
-            Validation.NotEmpty(nameof(b), b.Length);
-            Validation.NotEmpty(nameof(c), c.Length);
-            Validation.NotEmpty(nameof(d), d.Length);
-            Validation.NotEmpty(nameof(e), e.Length);
-            Validation.NotEmpty(nameof(f), f.Length);
             Validation.EqualToSize(nameof(a), a.Length, buffer.Length - b.Length - c.Length - d.Length - e.Length - f.Length);
             Validation.EqualToSize(nameof(b), b.Length, buffer.Length - a.Length - c.Length - d.Length - e.Length - f.Length);
             Validation.EqualToSize(nameof(c), c.Length, buffer.Length - a.Length - b.Length - d.Length - e.Length - f.Length);