public void TestFirstAndLast()
{
BTreeDictionary <int, string> data = new BTreeDictionary <int, string>(Comparer);
data.Add(1, "a");
data.Add(2, "b");
data.Add(3, "c");
data.Add(4, "d");
data.Add(5, "e");
Assert.AreEqual(1, data.First().Key);
Assert.AreEqual("a", data.First().Value);
data.Remove(1);
Assert.AreEqual(2, data.First().Key);
Assert.AreEqual("b", data.First().Value);
Assert.AreEqual(5, data.Last().Key);
Assert.AreEqual("e", data.Last().Value);
data.Remove(5);
Assert.AreEqual(4, data.Last().Key);
Assert.AreEqual("d", data.Last().Value);
data.Remove(4);
data.Remove(3);
KeyValuePair <int, string> kv;
Assert.IsTrue(data.TryGetLast(out kv));
Assert.IsTrue(data.TryGetFirst(out kv));
data.Remove(2);
Assert.IsFalse(data.TryGetLast(out kv));
Assert.IsFalse(data.TryGetFirst(out kv));
try
{
data.First();
Assert.Fail("Should raise InvalidOperationException");
}
catch (InvalidOperationException)
{
}
try
{
data.Last();
Assert.Fail("Should raise InvalidOperationException");
}
catch (InvalidOperationException)
{
}
}