// COMPILER_ARGUMENTS: -XXLanguage:+AllowContractsForCustomFunctions -XXLanguage:+UseReturnsEffect package test import kotlin.contracts.* @OptIn(ExperimentalContracts::class) fun myRequire(x: Boolean) { contract { returns() implies x } } fun testContractFromSource(x: Any?, y: Any?) { myRequire(x is String) myRequire(y is String) x.length myRequire(x is Int) }