fun box(): String { return Z().test() } class Z { fun Double.test(a: Int, b: Long, c: () -> String): String { return "${this.toInt()}_${a}_${b}_${c()}" } fun test(): String { var invokeOrder = ""; val expectedResult = "1_0_1_L" val expectedInvokeOrder = "1_0_L" var l = 1L var i = 0 var result = 1.0.test(b = { invokeOrder += "1_"; l }(), a = { invokeOrder += "0_"; i }(), c = { invokeOrder += "L"; "L" }) if (invokeOrder != expectedInvokeOrder || result != expectedResult) return "fail 1: $invokeOrder != $expectedInvokeOrder or $result != $expectedResult" invokeOrder = ""; result = 1.0.test(b = { invokeOrder += "1_"; l }(), c = { invokeOrder += "L"; "L" }, a = { invokeOrder += "0_"; i }()) if (invokeOrder != expectedInvokeOrder || result != expectedResult) return "fail 2: $invokeOrder != $expectedInvokeOrder or $result != $expectedResult" invokeOrder = ""; result = 1.0.test(c = { invokeOrder += "L"; "L" }, b = { invokeOrder += "1_"; l }(), a = { invokeOrder += "0_"; i }()) if (invokeOrder != expectedInvokeOrder || result != expectedResult) return "fail 3: $invokeOrder != $expectedInvokeOrder or $result != $expectedResult" invokeOrder = ""; result = 1.0.test(a = { invokeOrder += "0_"; i }(), c = { invokeOrder += "L"; "L" }, b = { invokeOrder += "1_"; l }()) if (invokeOrder != "0_1_L" || result != expectedResult) return "fail 4: $invokeOrder != 0_1_L or $result != $expectedResult" return "OK" } }