Direct tuple assignment in for comprehension

TupleAssign.scala

// Run with scala-cli TupleAssing.scala
//
// //> using scala "3.3.1"
//> using scala "3.4.0-RC1-bin-20231109-c7b3d7b-NIGHTLY"
//> using lib "dev.zio::zio:2.0.19"

// (required before Scala 3.4)
// //> using options -source:future

import zio.*

@main
def main() =
    // Pure scala:
    def x =
        for
            (a, b) <- Some(1, 2)
        yield (a, b)

    println(x.get)

    // With ZIO unpacking separately (works):
    def y =
        for
            x <- ZIO.fromOption(Some(1, 2))
            (a, b) = x
        yield (a, b)

    println(runZIO(y))

    // With ZIO unpacking directly (doesn't work unless using "-source:future"):
    def z =
        for
            (a, b) <- ZIO.fromOption(Some(1, 2))
        yield (a, b)

    println(runZIO(z))
end main

// Helper to run ZIO effects:
def runZIO(eff: ZIO[Any, Any, Any]): Any =
    Unsafe.unsafe { implicit unsafe =>
        Runtime.default.unsafe.run(eff).getOrThrowFiberFailure()
    }