Bug #2764: Hash.new inconsistency when initialized with an enumerable

• Status: Rejected
• Assignee: -
• ruby -v: ruby 1.8.7 (2009-04-08 patchlevel 160) [i686-darwin9]

[florent (Florent Vaucelle)]

=begin
When initializing a Hash with an enumerable as default value, Hash.new(obj) and Hash.new(&block) have different behaviours.

Example:
h = Hash.new([])
h[10] << 20
h #=> {}

h = Hash.new { |hash, key| hash[key] = [] }
hash[10] << 20
h #=> {10=>20}

The example similar when using a String instead of an Array as default value.
=end

[marcandre (Marc-Andre Lafortune)]

• Category set to core
• Status changed from Open to Rejected

=begin
This is by design.

Note that the behavior is actually different for all types of objects, even immediates

h = Hash.new(42)
h[:foo] # ==> 42
h.keys # ==> []

h = Hash.new { |hash, key| hash[key] = 42 }
h[:foo] # ==> 42
h.keys # ==> [:foo]

=end