1 files changed, 22 insertions, 0 deletions
diff --git a/test/dl/test_cptr.rb b/test/dl/test_cptr.rb
index 3c4b5e6867..43605f84ce 100644
--- a/test/dl/test_cptr.rb
+++ b/test/dl/test_cptr.rb
@@ -3,6 +3,28 @@ require_relative '../ruby/envutil'
 
 module DL
   class TestCPtr < TestBase
+    def test_minus
+      str = "hello world"
+      ptr = CPtr[str]
+      assert_equal ptr.to_s, (ptr + 3 - 3).to_s
+    end
+
+    # TODO: what if the pointer size is 0?  raise an exception? do we care?
+    def test_plus
+      str = "hello world"
+      ptr = CPtr[str]
+      new_str = ptr + 3
+      assert_equal 'lo world', new_str.to_s
+    end
+
+    def test_inspect
+      ptr = CPtr.new(0)
+      inspect = ptr.inspect
+      assert_match(/size=#{ptr.size}/, inspect)
+      assert_match(/free=#{ptr.free}/, inspect)
+      assert_match(/ptr=#{ptr.to_i}/, inspect)
+    end
+
     def test_to_ptr_string
       str = "hello world"
       ptr = CPtr[str]