Add Country#=~ as an equivalent of Timezone#=~ (matching on code).

lib/tzinfo/country.rb

@@ -176,6 +176,16 @@ def hash
       code.hash
     end
 
+    # Matches `regexp` against the {code} of this {Country}.
+    #
+    # @param regexp [Regexp] a `Regexp` to match against the {code} of
+    #   this {Country}.
+    # @return [Integer] the position the match starts, or `nil` if there is no
+    #   match.
+    def =~(regexp)
+      regexp =~ code
+    end
+
     # Returns a serialized representation of this {Country}. This method is
     # called when using `Marshal.dump` with an instance of {Country}.
     #

test/tc_country.rb

@@ -166,6 +166,17 @@ def test_hash
     assert_equal('US'.hash, Country.get('US').hash)
   end
 
+  define_method("test_=~_operator_matches_against_code") do
+    c = Country.get('GB')
+    assert_equal(0, c =~ /\AGB\z/)
+    assert_equal(1, c =~ /B/)
+  end
+
+  define_method("test_=~_operator_returns_nil_when_regexp_does_not_match") do
+    c = Country.get('GB')
+    assert_nil(c =~ /US/)
+  end
+
   def test_marshal
     c = Country.get('US')
     marshalled_c = Marshal.load(Marshal.dump(c))