IsAbstract.scala

scala> import scala.reflect.runtime.universe._
import scala.reflect.runtime.universe._

scala> class Bar { type T; def bar = weakTypeTag[T] }
defined class Bar

scala> object Barr extends Bar { type T = Int }
defined object Barr

scala> val tag = Barr.bar
tag: reflect.runtime.universe.WeakTypeTag[Barr.T] = WeakTypeTag[Bar.this.T]

scala> tag.tpe.typeSymbol.asType.isAbstractType
<console>:16: warning: method isAbstractType in trait TypeSymbolApi is deprecated (since 2.11.0): use isAbstract instead
       tag.tpe.typeSymbol.asType.isAbstractType
                                 ^
res0: Boolean = true

scala> tag.tpe.typeSymbol.asType.isAbstract
res1: Boolean = true

scala> tag.tpe.typeSymbol.asType.isInstanceOf[FreeTypeSymbolApi]
res2: Boolean = true

scala> class Baz { type T; def baz(implicit tag: WeakTypeTag[T]) = weakTypeTag[T] }
defined class Baz

scala> object Bazz extends Baz { type T = Int }
defined object Bazz

scala> val tag = Bazz.baz
tag: reflect.runtime.universe.WeakTypeTag[Bazz.T] = TypeTag[Bazz.T]

scala> tag.tpe.typeSymbol.asType.isAbstractType
<console>:16: warning: method isAbstractType in trait TypeSymbolApi is deprecated (since 2.11.0): use isAbstract instead
       tag.tpe.typeSymbol.asType.isAbstractType
                                 ^
res3: Boolean = false
                                              
scala> tag.tpe.typeSymbol.asType.isAbstract
res4: Boolean = true

scala> tag.tpe.typeSymbol.asType.isInstanceOf[FreeTypeSymbolApi]
res5: Boolean = false