def crazytown(&block)
  String.new.instance_eval(&block)
end

crazytown do
  ScaryConst = 5
  p ScaryConst
end

p ScaryConst
p String::ScaryConst

				
		

		

	
	





prints: 





	
	

		

		

			
				
				

					
		
		
5
5
rspeq.rb:11: warning: toplevel constant ScaryConst referenced by String::ScaryConst
5