Unsound elimination of function calls in paths

[EugeneFlesselle]

Compiler version

3.6.1-RC1

Minimized code

@main def Test =

  trait A:
    type B >: Int <: Boolean

  def f(using a: A): a.type = a
  given a[X]: A = a

  val _: Boolean = 1 : f.B // ClassCastException

Note the dummy parameter X is necessary for a to be a def.

Expectation

Function calls used in paths should be evaluated, along with their arguments, even if they have singleton return types. We get the usual bad bounds problem otherwise.

[EugeneFlesselle]

Ah I just saw #21788, moving this minimization there.