An anonymous Struct in pure Ruby (hoping Ruby adds a real one)

struct_literal.rb

module StructLiteral
  refine Hash do
    def to_struct(class_name = nil)
      if class_name
        Object.const_set(class_name, Struct.new(*keys))
        Object.const_get(class_name).new(*values)
      else
        Struct.new(*keys).new(*values)
      end
    end

    alias ~@ to_struct
  end
end

using StructLiteral

~{aim: true, tip: :broadhead}
#=> #<struct aim=true, tip="broadhead">

{aim: true, tip: :broadhead}.to_struct(:Arrow)
#=> #<struct Arrow aim=true, tip=:broadhead>