When ExprType(T) has expected type Foo, we should add a constraint T <: Foo

[smarter]

Type inference should work the same for zero and one, but it doesn't, foo(1).zero has expected type 1 but this isn't added as a constraint, so we instantiate T to Int (because the only constraint is >: 1 and we widen when instantiating a singleton lower bound)

class Foo[T] {
  def zero: T = ???
  def one(): T = ???
}

object Test {
  def foo[T](x: T): Foo[T] = new Foo

  val a: 1 = foo(1).zero // Fails: Found: Int, required: Int(1)
  val b: 1 = foo(1).one() // OK
}

[odersky]

This one does not work either:

class Foo[T] {
  def zero: T = ???
  def one(): T = ???
  val two: T = ???
}

object Test {
  def foo[T](x: T): Foo[T] = new Foo

  val b: 1 = foo(1).one() // OK
  val a: 1 = foo(1).zero // Fails: Found: Int, required: Int(1)
  val c: 1 = foo(1).two  // Fails: Found: Int, required: Int(1)
}

So the problem applies to normal value types as well, ExprTypes are not special.