1 files changed, 45 insertions, 0 deletions
diff --git a/library/src/dotty/DottyPredef.scala b/library/src/dotty/DottyPredef.scala
new file mode 100644
index 000000000..cd90c4882
--- /dev/null
+++ b/library/src/dotty/DottyPredef.scala
@@ -0,0 +1,45 @@
+package dotty
+
+import scala.reflect.runtime.universe.TypeTag
+import scala.reflect.ClassTag
+import scala.Predef.???
+import scala.collection.Seq
+
+/** unimplemented implicit for TypeTag */
+object DottyPredef {
+  implicit def typeTag[T]: TypeTag[T] = ???
+
+  implicit def arrayTag[T](implicit ctag: ClassTag[T]): ClassTag[Array[T]] =
+    ctag.wrap
+
+  /** A fall-back implicit to compare values of any types.
+   *  The compiler will restrict implicit instances of `eqAny`. An instance
+   *  `eqAny[T, U]` is _valid_ if `T <: U` or `U <: T` or both `T` and `U` are
+   *  Eq-free. A type `S` is Eq-free if there is no implicit instance of `Eq[S, S]`.
+   *  An implicit search will fail instead of returning an invalid `eqAny` instance.
+   */
+  implicit def eqAny[L, R]: Eq[L, R] = Eq
+
+  implicit def eqNumber   : Eq[Number, Number] = Eq
+  implicit def eqString   : Eq[String, String] = Eq
+
+  // true asymmetry, modeling the (somewhat problematic) nature of equals on Proxies
+  implicit def eqProxy    : Eq[Proxy, Any]     = Eq
+
+  implicit def eqSeq[T, U](implicit eq: Eq[T, U]): Eq[Seq[T], Seq[U]] = Eq
+
+  implicit def eqByteNum  : Eq[Byte, Number]   = Eq
+  implicit def eqNumByte  : Eq[Number, Byte]   = Eq
+  implicit def eqCharNum  : Eq[Char, Number]   = Eq
+  implicit def eqNumChar  : Eq[Number, Char]   = Eq
+  implicit def eqShortNum : Eq[Short, Number]  = Eq
+  implicit def eqNumShort : Eq[Number, Short]  = Eq
+  implicit def eqIntNum   : Eq[Int, Number]    = Eq
+  implicit def eqNumInt   : Eq[Number, Int]    = Eq
+  implicit def eqLongNum  : Eq[Long, Number]   = Eq
+  implicit def eqNumLong  : Eq[Number, Long]   = Eq
+  implicit def eqFloatNum : Eq[Float, Number]  = Eq
+  implicit def eqNumFloat : Eq[Number, Float]  = Eq
+  implicit def eqDoubleNum: Eq[Double, Number] = Eq
+  implicit def eqNumDouble: Eq[Number, Double] = Eq
+}