Document Any.classify|categorize(*)

Author: lizmat

doc/Type/Any.pod6

@@ -884,7 +884,9 @@ Can take a separator, which is an empty string by default.
     multi sub categorize($test, +items, :$into!, *%named )
     multi sub categorize($test, +items, *%named )
 
-The two first forms fail with an error message.
+The first form will always fail. The second form classifies on the
+identity of the given object, which usually only makes sense in
+combination with the C<:&as> argument.
 
 In its simplest form, it uses a C<$test> whose result will be used as a key; the
 values of the key will be an array of the elements that produced that key as a
@@ -934,6 +936,9 @@ say (3..13).categorize( &divisible-by );
 In this case, every number in the range is classified in as many bins as it can
 be divided by.
 
+Support for using C<Whatever> as the test was added in Rakudo compiler
+version 2023.02.
+
 =head2 routine classify
 
     multi method classify()
@@ -943,10 +948,14 @@ be divided by.
     multi sub classify($test, +items, :$into!, *%named )
     multi sub classify($test, +items, *%named )
 
-The two first forms will fail. The rest include a C<$test>, which is a function
-that will return a scalar for every input; these will be used as keys of a hash
-whose values will be arrays with the elements that output that key for the test
-function.
+The first form will always fail. The second form classifies on the
+identity of the given object, which usually only makes sense in
+combination with the C<:&as> argument.
+
+The rest include a C<$test> argument, which is a function that will
+return a scalar for every input; these will be used as keys of a hash
+whose values will be arrays with the elements that output that key for
+the test function.
 
 =for code
 my @years = (2003..2008).map( { Date.new( $_~"-01-01" ) } );
@@ -963,6 +972,9 @@ into; in the example above, it's defined on the fly.
 
 From version 6.d, C<.classify> will also work with C<Junctions>.
 
+Support for using C<Whatever> as the test was added in Rakudo compiler
+version 2023.02.
+
 =head2 routine reduce
 
     multi method reduce(Any:U: & --> Nil)