Is there a way to determine whether a method in a trait has a default implementation?

[cacapouh]

Is there a way to determine whether a method in a trait has a default implementation?
I tried using defDef.rhs.isDefined, and this is my current code:

// ThisBuild / scalaVersion := "3.3.0-RC4"

// Macro.scala
import scala.quoted.*

object Macro {
  inline def m[T]: String = ${ impl[T] }

  def impl[T](using Quotes, Type[T]): Expr[String] = {
    import quotes.reflect.*

    def hasImpl(declaration: Symbol): Boolean = declaration.tree match
      case defdef: DefDef => defdef.rhs.isDefined
      case _              => false

    Expr(
      TypeRepr
        .of[T]
        .typeSymbol
        .declarations
        .map { d =>
          (d.name, hasImpl(d))
        }
        .toString
    )
  }
}

// Main.scala
trait TestTrait {
    def defaultImpl: Int = 1
    def method: Int
}

@main
def main() = {
    // expected: List((<init>,false), (defaultImpl,true), (method,false))
    // actual: List((<init>,false), (defaultImpl,false), (method,false))
    println(Macro.m[TestTrait])
}

[cacapouh]

I found that by checking the flags, we can determine whether an implementation exists or not.

def hasImpl(declaration: Symbol): Boolean = !declaration.flags.is(Flags.Deferred)