diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/set.rb | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/lib/set.rb b/lib/set.rb index e77af5de2e..43c388ca90 100644 --- a/lib/set.rb +++ b/lib/set.rb @@ -3,7 +3,7 @@ # # set.rb - defines the Set class #++ -# Copyright (c) 2002-2013 Akinori MUSHA <knu@iDaemons.org> +# Copyright (c) 2002-2016 Akinori MUSHA <knu@iDaemons.org> # # Documentation by Akinori MUSHA and Gavin Sinclair. # @@ -37,7 +37,8 @@ # Set uses Hash as storage, so you must note the following points: # # * Equality of elements is determined according to Object#eql? and -# Object#hash. +# Object#hash. Use Set#compare_by_identity to make a set compare +# its elements by their identity. # * Set assumes that the identity of each element does not change # while it is stored. Modifying an element of a set will render the # set to an unreliable state. @@ -91,6 +92,23 @@ class Set end end + # Makes the set compare its elements by their identity and returns + # self. This method may not be supported by all subclasses of Set. + def compare_by_identity + if @hash.respond_to?(:compare_by_identity) + @hash.compare_by_identity + self + else + raise NotImplementedError, "#{self.class.name}\##{__method__} is not implemented" + end + end + + # Returns true if the set will compare its elements by their + # identity. Also see Set#compare_by_identity. + def compare_by_identity? + @hash.respond_to?(:compare_by_identity?) && @hash.compare_by_identity? + end + def do_with_enum(enum, &block) # :nodoc: if enum.respond_to?(:each_entry) enum.each_entry(&block) if block |