Documentation for context bound desugaring disagrees with implementation

[griggt]

Compiler version

3.1.2

Minimized code

trait C1[T]; trait C2[T]; trait C3[T]
trait V; trait R

trait Test:
  def f[T: C1 : C2, U: C3](x: T)(using y: U, z: V): R

Output

$ scalac -Xprint:typer -source:future context-bound-params.scala
[[syntax trees at end of                     typer]] // context-bound-params.scala
package <empty> {
  trait C1[T >: Nothing <: Any]() extends Object {
    T
  }
  trait C2[T >: Nothing <: Any]() extends Object {
    T
  }
  trait C3[T >: Nothing <: Any]() extends Object {
    T
  }
  trait V() extends Object {}
  trait R() extends Object {}
  trait Test() extends Object {
    def f[T >: Nothing <: Any, U >: Nothing <: Any](x: T)(using 
      evidence$1: C1[T]
    , evidence$2: C2[T], evidence$3: C3[U], y: U, z: V): R
  }
}

Expectation

The documentation at https://docs.scala-lang.org/scala3/reference/contextual/context-bounds.html states:

For instance,

def f[T: C1 : C2, U: C3](x: T)(using y: U, z: V): R

would expand to

def f[T, U](x: T)(using y: U, z: V)(using C1[T], C2[T], C3[U]): R

Note that this differs from the implementation both in the number of using clauses and the ordering of context parameters.