Stop GetRange's range check overflowing for large counts

Containers.Test/ContiguousCollectionTests.cs

@@ -417,6 +417,29 @@ public void GetRange_InvalidParameters_ThrowsArgumentOutOfRangeException()
 		Assert.ThrowsExactly<ArgumentOutOfRangeException>(() => collection.GetRange(1, 3));
 	}
 
+	[TestMethod]
+	public void GetRange_CountOverflowingStartIndex_ThrowsArgumentOutOfRangeException()
+	{
+		// Arrange
+		ContiguousCollection<int> collection = [.. new int[] { 1, 2, 3 }];
+
+		// Act & Assert: startIndex + count overflows int
+		Assert.ThrowsExactly<ArgumentOutOfRangeException>(() => collection.GetRange(1, int.MaxValue));
+	}
+
+	[TestMethod]
+	public void GetRange_ZeroCountAtEnd_ReturnsEmpty()
+	{
+		// Arrange
+		ContiguousCollection<int> collection = [.. new int[] { 1, 2, 3 }];
+
+		// Act
+		ContiguousCollection<int> range = collection.GetRange(collection.Count, 0);
+
+		// Assert
+		Assert.IsEmpty(range);
+	}
+
 	[TestMethod]
 	public void Clone_CreatesShallowCopy()
 	{

Containers.Test/InsertionOrderCollectionTests.cs

@@ -405,6 +405,29 @@ public void GetRange_InvalidCount_ThrowsArgumentOutOfRangeException()
 		Assert.ThrowsExactly<ArgumentOutOfRangeException>(() => collection.GetRange(1, 3));
 	}
 
+	[TestMethod]
+	public void GetRange_CountOverflowingStartIndex_ThrowsArgumentOutOfRangeException()
+	{
+		// Arrange
+		InsertionOrderCollection<int> collection = [.. new int[] { 1, 2, 3 }];
+
+		// Act & Assert: startIndex + count overflows int
+		Assert.ThrowsExactly<ArgumentOutOfRangeException>(() => collection.GetRange(1, int.MaxValue));
+	}
+
+	[TestMethod]
+	public void GetRange_ZeroCountAtEnd_ReturnsEmpty()
+	{
+		// Arrange
+		InsertionOrderCollection<int> collection = [.. new int[] { 1, 2, 3 }];
+
+		// Act
+		InsertionOrderCollection<int> range = collection.GetRange(collection.Count, 0);
+
+		// Assert
+		Assert.IsEmpty(range);
+	}
+
 	[TestMethod]
 	public void Clone_CreatesShallowCopy()
 	{

Containers.Test/OrderedCollectionTests.cs

@@ -484,6 +484,16 @@ public void GetRange_ZeroCountAtEnd_ReturnsEmpty()
 		Assert.AreEqual(0, range.Count);
 	}
 
+	[TestMethod]
+	public void GetRange_CountOverflowingStartIndex_ThrowsArgumentOutOfRangeException()
+	{
+		// Arrange
+		OrderedCollection<int> collection = new([1, 2, 3]);
+
+		// Act & Assert: startIndex + count overflows int
+		Assert.ThrowsExactly<ArgumentOutOfRangeException>(() => collection.GetRange(1, int.MaxValue));
+	}
+
 	[TestMethod]
 	public void GetRange_ZeroCountOnEmptyCollection_ReturnsEmpty()
 	{

Containers/ContiguousCollection.cs

@@ -376,7 +376,7 @@ public ContiguousCollection<T> GetRange(int startIndex, int count)
 	{
 		ArgumentOutOfRangeException.ThrowIfNegative(startIndex);
 		ArgumentOutOfRangeException.ThrowIfNegative(count);
-		ArgumentOutOfRangeException.ThrowIfGreaterThan(startIndex + count, Count);
+		ArgumentOutOfRangeException.ThrowIfGreaterThan(count, Count - startIndex);
 		ContiguousCollection<T> result = new(count);
 		Array.Copy(items, startIndex, result.items, 0, count);
 		result.Count = count;

Containers/InsertionOrderCollection.cs

@@ -194,7 +194,7 @@ public InsertionOrderCollection<T> GetRange(int startIndex, int count)
 	{
 		ArgumentOutOfRangeException.ThrowIfNegative(startIndex);
 		ArgumentOutOfRangeException.ThrowIfNegative(count);
-		ArgumentOutOfRangeException.ThrowIfGreaterThan(startIndex + count, Count);
+		ArgumentOutOfRangeException.ThrowIfGreaterThan(count, Count - startIndex);
 
 		return [.. items.GetRange(startIndex, count)];
 	}

Containers/OrderedCollection.cs

@@ -354,7 +354,7 @@ public OrderedCollection<T> GetRange(int startIndex, int count)
 	{
 		ArgumentOutOfRangeException.ThrowIfNegative(startIndex);
 		ArgumentOutOfRangeException.ThrowIfNegative(count);
-		ArgumentOutOfRangeException.ThrowIfGreaterThan(startIndex + count, Count);
+		ArgumentOutOfRangeException.ThrowIfGreaterThan(count, Count - startIndex);
 
 		List<T> rangeItems = items.GetRange(startIndex, count);
 		return new OrderedCollection<T>(rangeItems, comparer);