* encoding.c: Mention that Encoding.compatible? can work with more

	  than just Strings.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@31978 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 11 insertions, 5 deletions

diff --git a/encoding.c b/encoding.c
index abc63f3c58..a88d176c0f 100644
--- a/encoding.c
+++ b/encoding.c
@@ -1042,12 +1042,13 @@ enc_find(VALUE klass, VALUE enc)
 
 /*
  * call-seq:
- *   Encoding.compatible?(str1, str2) -> enc or nil
+ *   Encoding.compatible?(obj1, obj2) -> enc or nil
  *
- * Checks the compatibility of two strings.
- * If they are compatible, means concatenatable,
- * returns an encoding which the concatenated string will be.
- * If they are not compatible, nil is returned.
+ * Checks the compatibility of two objects.
+ *
+ * If the objects are both strings they are compatible when they are
+ * concatenatable.  The encoding of the concatenated string will be returned
+ * if they are compatible, nil if they are not.
  *
  *   Encoding.compatible?("\xa1".force_encoding("iso-8859-1"), "b")
  *   #=> #<Encoding:ISO-8859-1>
@@ -1057,6 +1058,11 @@ enc_find(VALUE klass, VALUE enc)
  *     "\xa1\xa1".force_encoding("euc-jp"))
  *   #=> nil
  *
+ * If the objects are non-strings their encodings are compatible when they
+ * have an encoding and:
+ * * Either encoding is US ASCII compatible
+ * * One of the encodings is a 7-bit encoding
+ *
  */
 static VALUE
 enc_compatible_p(VALUE klass, VALUE str1, VALUE str2)