simple_bech_methods.rb

class String
  def method_missing(name, *args, &block)
    name == :ghost_capitalize ? capitalize : super
  end
end

require 'benchmark'
Benchmark.bmbm do |b|
  b.report "Normal method" do
    1_000_000.times { "abc".capitalize }
  end
  b.report "Ghost method" do
    1_000_000.times { "abc".ghost_capitalize }
  end
end