// !USE_EXPERIMENTAL: kotlin.contracts.ExperimentalContracts
// IGNORE_BACKEND: NATIVE

// FILE: 1.kt

package test

import kotlin.contracts.*

public inline fun <R> myrun(block: () -> R): R {
    contract {
        callsInPlace(block, InvocationKind.EXACTLY_ONCE)
    }
    return block()
}

// FILE: 2.kt

import test.*

fun box(): String {
    val x: Int
    myrun {
        myrun {
            x = 42
        }
    }
    return if (x.inc() == 43) "OK" else "Fail: ${x.inc()}"
}