rubys-interface.rb

methods = Hash.new do |hash, klass|
  klass.instance_methods.each do |mid|
    m = klass.instance_method mid rescue next
    hash[m.name] = [] unless hash.key? m.name
    hash[m.name] |= [klass]
  end
end

ObjectSpace.each_object(Class) do |klass|
  methods[klass]
end

methods = methods.to_a.sort_by do |mid, klasses|
  -klasses.count
end

require 'pp'
pp methods.
     map { |mid, mods| [mid, mods.count] }.
     select { |_, n| n > 1 }

__END__

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