require("cpp17_enable_if_t")
assert(cpp17_enable_if_t.enableif5(10, 20) == 30, "enableif5")
cpp17_enable_if_t.tester()
cpp17_enable_if_t.tester2()
assert(cpp17_enable_if_t.Enum1 == 1)
assert(cpp17_enable_if_t.Enum2 == 2)