Ruby's smart enough to freeze regexen by default. I think that landed around 2.0/2.1/2.2 pry(main)> 3.times { puts /i_am_a_reg_ex/.object_id } 7013197867

Ruby's smart enough to freeze regexen by default. I think that landed around 2.0/2.1/2.2 pry(main)> 3.times { puts /i_am_a_reg_ex/.object_id } 70131978677720 70131978677720 70131978677720