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cover_vs_include_performance

⚡️ Optimize Checks with Range#cover? vs include?​

Use cover? for numerical ranges to get O(1) boundary checks, whereas include? may iterate, causing O(n) cost. In performance‐sensitive code (e.g., hot loops or validations), prefer cover? for primitive objects.

range = (1..1_000_000)

Benchmark.ips do |x|
  x.report("include? 999_999") { range.include?(999_999) }
  x.report("cover?   999_999") { range.cover?(999_999) }
  x.compare!
end

# include? iterates; cover? uses arithmetic -> significantly faster