# File lib/facets/core/enumerable/to_h.rb, line 18
  def to_h( &blk )
    h = {}
    if block_given?
      each_with_index{ |e,i| h[i] = blk.call(e,i) }
    else
      each_with_index{ |e,i| h[i] = e }
    end
    h
  end