Array#to_h Hash#to_h which can take blocks

array_to_h.rb

class Array
  def to_h(&block)
    ary = block_given? ? self.collect(&block) : self
    Hash[*ary.flatten]
  end
end

class Hash
  def to_h(&block)
    return self if !block_given?
    Hash[*self.collect(&block).flatten]
  end
end

if __FILE__ == $0
  require 'test/unit'

  class ArrayToHashTest < Test::Unit::TestCase
    HASH = { :bacon => 42, :tasty => 52 }

    def test_array_to_h
      result = [[:bacon,42], [:tasty,52]].to_h
      assert_equal HASH, result
    end

    def test_array_to_h_with_block
      result = [[30, :bacon], [40, :tasty]].to_h { |k, v| [v, k+12] }
      assert_equal HASH, result
    end

    def test_hash_to_h
      assert_equal HASH, HASH.to_h
    end

    def test_hash_to_h_with_block
      result = ({ 30 => :bacon, 40 => :tasty }).to_h { |k, v| [v, k+12] }
      assert_equal HASH, result
    end
  end
end