> Alright, numbers would've been helpful but I'll take your word
> for it.
My bad, I didn't get the hint:
```
require 'benchmark/ips'
class Foo
attr_accessor :foo
def initialize
@foo = 1
end
def missing_ivar
@bar
end
def ivar
@foo
end
def accessor
foo
end
end
foo = Foo.new
Benchmark.ips do |x|
x.report('ivar') { foo.ivar }
x.report('attr') { foo.accessor }
x.report('ivar:missing') { foo.missing_ivar }
x.compare!
end
```
ruby 2.7.1p83 (2020-03-31 revision a0c7c23c9c) [x86_64-darwin19]
Warming up --------------------------------------
ivar 2.105M i/100ms
attr 1.824M i/100ms
ivar:missing 1.795M i/100ms
Calculating -------------------------------------
ivar 20.935M (± 1.5%) i/s - 105.248M in 5.028625s
attr 18.622M (± 0.8%) i/s - 94.845M in 5.093471s
ivar:missing 18.408M (± 1.1%) i/s - 93.357M in 5.072160s
Comparison:
ivar: 20934740.7 i/s
attr: 18622122.9 i/s - 1.12x (± 0.00) slower
ivar:missing: 18408273.1 i/s - 1.14x (± 0.00) slower
So yeah, the difference between raw @ivar and an attr_reader is barely
noticeable, and both are very fast.
