[DOC] Tweaks for String#center

Author: BurdetteLamar

doc/string/center.rdoc

@@ -2,15 +2,19 @@ Returns a centered copy of +self+.
 
 If integer argument +size+ is greater than the size (in characters) of +self+,
 returns a new string of length +size+ that is a copy of +self+,
-centered and padded on both ends with +pad_string+:
+centered and padded on one or both ends with +pad_string+:
 
-  'hello'.center(10)       # => "  hello   "
-  '  hello'.center(10)     # => "   hello  "
-  'hello'.center(10, 'ab') # => "abhelloaba"
-  'тест'.center(10)        # => "   тест   "
-  'こんにちは'.center(10)    # => "  こんにちは   "
+  'hello'.center(6)             # => "hello "               # Padded on one end.
+  'hello'.center(10)            # => "  hello   "           # Padded on both ends.
+  'hello'.center(20, '-|')      # => "-|-|-|-hello-|-|-|-|" # Some padding repeated.
+  'hello'.center(10, 'abcdefg') # => "abhelloabc"           # Some padding not used.
+  '  hello  '.center(13)        # => "    hello    "
+  'тест'.center(10)             # => "   тест   "
+  'こんにちは'.center(10)         # => "  こんにちは   "      # Multi-byte characters.
 
-If +size+ is not greater than the size of +self+, returns a copy of +self+:
+If +size+ is less than or equal to the size of +self+, returns an unpadded copy of +self+:
 
-  'hello'.center(5)  # => "hello"
-  'hello'.center(1)  # => "hello"
+  'hello'.center(5)   # => "hello"
+  'hello'.center(-10) # => "hello"
+
+Related: see {Converting to New String}[rdoc-ref:String@Converting+to+New+String].

string.c

@@ -11117,8 +11117,6 @@ rb_str_rjust(int argc, VALUE *argv, VALUE str)
  *
  *  :include: doc/string/center.rdoc
  *
- *  Related: String#ljust, String#rjust.
- *
  */
 
 static VALUE

string.rb

@@ -443,7 +443,7 @@
 #
 # - #*: Returns the concatenation of multiple copies of +self+.
 # - #+: Returns the concatenation of +self+ and a given other string.
-# - #center: Returns a copy of +self+ centered between pad substrings.
+# - #center: Returns a copy of +self+, centered by specified padding.
 # - #concat: Returns the concatenation of +self+ with given other strings.
 # - #prepend: Returns the concatenation of a given other string with +self+.
 # - #ljust: Returns a copy of +self+ of a given length, right-padded with a given other string.