TIL there is an o modifier doing the same thanks to @eregon

[PragTob]

It's even a tiny bit faster it seems.

Memoization:
tobi@speedy ~/github/simplecov $ bundle exec ruby benchmarks/result.rb
Warming up --------------------------------------
generating a simplecov result
                        28.000  i/100ms
Calculating -------------------------------------
generating a simplecov result
                        282.997  (± 1.4%) i/s -      1.428k in   5.047055s

Modifier:
tobi@speedy ~/github/simplecov $ bundle exec ruby benchmarks/result.rb
Warming up --------------------------------------
generating a simplecov result
                        28.000  i/100ms
Calculating -------------------------------------
generating a simplecov result
                        289.115  (± 1.7%) i/s -      1.456k in   5.037437s