async_let_isolation.swift

// First without any concurrency enabled.
// RUN: %target-swift-frontend -target %target-swift-5.1-abi-triple %s -emit-sil -o /dev/null -verify -verify-additional-prefix without-transferring-

// Then with targeted.
// RUN: %target-swift-frontend -target %target-swift-5.1-abi-triple %s -emit-sil -o /dev/null -verify -strict-concurrency=targeted -verify-additional-prefix without-transferring-

// Then strict-concurrency with everything.
// RUN: %target-swift-frontend -target %target-swift-5.1-abi-triple %s -emit-sil -o /dev/null -verify -strict-concurrency=complete -verify-additional-prefix tns-

// REQUIRES: concurrency
// REQUIRES: asserts

actorMyActor{
letimmutable:Int=17
vartext:[String]=[]

func synchronous()->String{ text.first ??"nothing"}
func asynchronous()async->String{synchronous()}

func testAsyncLetIsolation()async{
asyncletx=self.synchronous()
asynclety=awaitself.asynchronous()
asyncletz=synchronous()

varlocalText= text

asyncletw= localText.removeLast() // expected-without-transferring-warning {{mutation of captured var 'localText' in concurrently-executing code}}

 _ =await x
 _ =await y
 _ =await z
 _ =await w
}
}

finalclassMyFinalActor{
letimmutable:Int=17
vartext:[String]=[]

func testAsyncLetIsolation()async{
varlocalText= text
asyncletw= localText.removeLast() // expected-without-transferring-warning {{mutation of captured var 'localText' in concurrently-executing code}}

 _ =await w

}
}

func outside()async{
leta=MyActor()
asyncletx= a.synchronous() // okay, await is implicit
asynclety=await a.synchronous()
 _ =await x
 _ =await y
}