[DOC] Doc for StringIO.getc

Author: BurdetteLamar

doc/stringio/getc.rdoc

@@ -1,4 +1,4 @@
-Reads and returns the next character from the stream:
+Reads and returns the next character (or byte; see below) from the stream:
 
   strio = StringIO.new('foo')
   strio.getc # => "f"
@@ -20,4 +20,15 @@ Returns characters, not bytes:
   strio.getc # => "こ"
   strio.getc # => "ん"
 
+In each of the examples above, the stream is positioned at the beginning of a character;
+in other cases that need not be true:
+
+   strio = StringIO.new('こんにちは')  # Five 3-byte characters.
+   strio.pos = 3 # => 3     # At beginning of second character; returns character.
+   strio.getc    # => "ん"
+   strio.pos = 4 # => 4     # At second byte of second character; returns byte.
+   strio.getc    # => "\x82"
+   strio.pos = 5 # => 5     # At third byte of second character; returns byte.
+   strio.getc    # => "\x93"
+
 Related: StringIO.getbyte.

ext/stringio/stringio.c

@@ -956,7 +956,7 @@ strio_each_byte(VALUE self)
 
 /*
  * call-seq:
- *   getc -> character or nil
+ *   getc -> character, byte, or nil
  *
  * :include: stringio/getc.rdoc
  *