given macros.scala

// macro.scala
import scala.quoted.*

trait Show[T]:
  def show(value: T): String

inline given showInstance[T]: Show[T] = ${ showInstanceImpl[T] }

def showInstanceImpl[T: Type](using Quotes) = '{ 
  new Show[T] { 
    def show(value: T) = 
      s"Type: ${${Expr(Type.show[T])}}, Value: $value" 
  }
  }

// main.scala
def printShow[T](value: T) =
  println(summon[Show[T]].show(value))

@main def main =
  printShow(42)
  printShow("Scala 3")