diff --git a/ChangeLog b/ChangeLog
index 8c688e962f945f..5f88df10ea64db 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Fri Dec 12 22:36:44 2003  NAKAMURA, Hiroshi  <nahi@ruby-lang.org>
+
+	* lib/csv.rb: add Cell#to_str and Cell#to_s for /.../ =~ aCell,
+	  "#{aCell}" and so on.
+
+	* test/csv/test_csv.rb: add tests.
+
 Fri Dec 12 19:33:06 2003  Minero Aoki  <aamine@loveruby.net>
 
 	* lib/fileutils.rb (mkdir): remove trailing `/' from pathes.
diff --git a/lib/csv.rb b/lib/csv.rb
index 10c86f641760e6..cfc5489ea091ce 100644
--- a/lib/csv.rb
+++ b/lib/csv.rb
@@ -85,6 +85,20 @@ def ==(rhs)
         @data == rhs.data
       end
     end
+
+    def to_str
+      content.to_str
+    end
+
+    def to_s
+      content.to_s
+    end
+
+  private
+
+    def content
+      @is_null ? nil : data
+    end
   end
   
 
diff --git a/test/csv/test_csv.rb b/test/csv/test_csv.rb
index 782f5af8d4d18c..6cc4c5cac7921b 100644
--- a/test/csv/test_csv.rb
+++ b/test/csv/test_csv.rb
@@ -1,4 +1,5 @@
-require 'test/unit'
+require 'test/unit/testsuite'
+require 'test/unit/testcase'
 require 'tempfile'
 require 'fileutils'
 
@@ -92,6 +93,29 @@ def test_Cell_s_new
     d3 = CSV::Cell.new(nil, false)
     assert_equal(d3.is_null, false, "Data: false.")
   end
+
+  def test_to_str
+    d = CSV::Cell.new("foo", false)
+    assert_equal("foo", d.to_str)
+    assert(/foo/ =~ d)
+    d = CSV::Cell.new("foo", true)
+    begin
+      d.to_str
+      assert(false)
+    rescue
+      # NoMethodError or NameError
+      assert(true)
+    end
+  end
+
+  def test_to_s
+    d = CSV::Cell.new("foo", false)
+    assert_equal("foo", d.to_s)
+    assert_equal("foo", "#{d}")
+    d = CSV::Cell.new("foo", true)
+    assert_equal("", d.to_s)
+    assert_equal("", "#{d}")
+  end
 end