API doc tweaks.

p4raw-id: //depot/perl@18760

diff --git a/utf8.c b/utf8.c
index 19d5ce5..261b1d9 100644 (file)
--- a/utf8.c
+++ b/utf8.c
@@ -217,10 +217,10 @@ Perl_is_utf8_char(pTHX_ U8 *s)
 /*
 =for apidoc A|bool|is_utf8_string|U8 *s|STRLEN len
 
-Returns true if first C<len> bytes of the given string form a valid UTF8
-string, false otherwise.  Note that 'a valid UTF8 string' does not mean
-'a string that contains UTF8' because a valid ASCII string is a valid
-UTF8 string.
+Returns true if first C<len> bytes of the given string form a valid
+UTF8 string, false otherwise.  Note that 'a valid UTF8 string' does
+not mean 'a string that contains code points above 0x7F encoded in
+UTF8' because a valid ASCII string is a valid UTF8 string.
 
 =cut
 */
@@ -770,6 +770,9 @@ Converts a string C<s> of length C<len> from ASCII into UTF8 encoding.
 Returns a pointer to the newly-created string, and sets C<len> to
 reflect the new length.
 
+If you want to convert to UTF8 from other encodings than ASCII,
+see sv_recode_to_utf8().
+
 =cut
 */