result.sh

% ruby --disable-gems test.rb
{:T_HASH=>1, :T_DATA=>2}
{:T_ARRAY=>1, :T_HASH=>1, :T_DATA=>1}

test.rb

def myroot2(&block)
  myfunc2(Time.now, {"a"=>1, "b"=>2}, &block)
end

def myfunc2(time, record)
  yield time, record
end


def myroot1
  time, record = myfunc1(Time.now, {"a"=>1, "b"=>2})
  yield time, record
end

def myfunc1(time, record)
  return time, record
end

h0={}
h1={}
h2={}
ObjectSpace.count_objects(h0)
GC.disable
ObjectSpace.count_objects(h0)

#p :block_and_yield
myroot2{|t,r| t; r; 1}
ObjectSpace.count_objects(h1)

#p :multi_value_return
myroot1{|t,r| t; r; 1}
ObjectSpace.count_objects(h2)

p h1.keys.map{|k|[k,h1[k]-h0[k]]}.select{|(a,b)|b>0}.to_h
p h1.keys.map{|k|[k,h2[k]-h1[k]]}.select{|(a,b)|b>0}.to_h