Rename CI_Utf8::_is_ascii() to is_ascii() and make it public
No reason for it to be protected.
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index ca31669..bda4cba 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -505,6 +505,7 @@
- ``UTF8_ENABLED`` now requires only one of `Multibyte String <http://php.net/mbstring>`_ or `iconv <http://php.net/iconv>`_ to be available instead of both.
- Changed method ``clean_string()`` to utilize ``mb_convert_encoding()`` if it is available but ``iconv()`` is not.
+ - Renamed method ``_is_ascii()`` to ``is_ascii()`` and made it public.
- Added `compatibility layers <general/compatibility_functions>` for PHP's `mbstring <http://php.net/mbstring>`_ (limited support) and `password <http://php.net/password>`_ extensions.
- Removed ``CI_CORE`` boolean constant from *CodeIgniter.php* (no longer Reactor and Core versions).