False type mismatch involving the singleton type of the result of a transparent inline method

Compiler version

3.1.2

Minimized code

trait Quotes

transparent inline def quotes(using q: Quotes) = q

class QuotesExt[Q <: Quotes]

object QuotesExt {
  def apply(q: Quotes): QuotesExt[q.type] =
    new QuotesExt[q.type]
}

def foo(q: Quotes, qe: QuotesExt[q.type]): Unit =
  ()

def doesNotCompile(using Quotes): Unit =
  foo(quotes, QuotesExt(quotes))

// Workaround 1: use explicit type annotation
def compiles(using Quotes): Unit =
  foo(quotes: quotes.type, QuotesExt(quotes))

// Workaround 2: avoid the transparent inline method `quotes`
def alsoCompiles(using q: Quotes): Unit =
  foo(q, QuotesExt(q))

Output

-- [E007] Type Mismatch Error: test.scala:16:23 --------------------------------
16 |  foo(quotes, QuotesExt(quotes))
   |              ^^^^^^^^^^^^^^^^^
   |      Found:    QuotesExt[(x$1 : Quotes)]
   |      Required: QuotesExt[(?1 : (using q: Quotes): Quotes)]
   |
   |      where:    ?1 is an unknown value of type (using q: Quotes): Quotes

longer explanation available when compiling with `-explain`
1 error found

Expectation

The code should compile.

[nicolasstucki]

Workaround

- def foo(q: Quotes, qe: QuotesExt[q.type]): Unit =
+ def foo(q: Quotes)(qe: QuotesExt[q.type]): Unit =

[mbovel]

Note: if foo is curried, then the snippet compiles successfully:

object Foo
transparent inline def id(x: Object) = x
def sameType(x: Object)(y: x.type) = true
val x = sameType(id(Foo))(Foo)