# .skip. In 2006-05 I determined that I probably don't need a truth coalesce operator. Leave it be for now.
class Test

	def main
		# ?? is a binary operator for truth coalescence
		i = 0
		assert i ?? 5 == 5
		i = 1
		assert i ?? 5 == 1
		
		t as List<of String> = List<of String>()
		u as List<of String> = List<of String>()
		assert t ?? u is u
		t.add('aoeu')
		assert t ?? u is t
		
		# ?? is also a unary postfix operator for truth detection
		i = 0
		visited = 0
		if i?
			visited = 1
		assert visited==1
		
		i = 5
		visited = 0
		if i?
			visited = 1
		assert visited==0

		# try ? unary postfix in more complex expression
		i = 5
		j as int? = 6
		visited = 0
		if i? and j?
			visited = 1
		assert visited==0
		visited = 0
		i = nil
		j = nil
		if i? and j?
			visited = 1
		assert visited==1