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Fix #1737: Enable GADT checking for objects #1740

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Merged
merged 1 commit into from
Nov 24, 2016
Merged

Fix #1737: Enable GADT checking for objects #1740

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4 changes: 3 additions & 1 deletion compiler/src/dotty/tools/dotc/typer/Typer.scala
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Original file line number Diff line number Diff line change
Expand Up @@ -1830,7 +1830,9 @@ class Typer extends Namer with TypeAssigner with Applications with Implicits wit
ctx.typeComparer.GADTused = false
if (ctx.mode is Mode.Pattern) {
tree match {
case _: RefTree | _: Literal if !isVarPattern(tree) =>
case _: RefTree | _: Literal
if !isVarPattern(tree) &&
!(tree.tpe <:< pt)(ctx.addMode(Mode.GADTflexible)) =>
checkCanEqual(pt, wtp, tree.pos)(ctx.retractMode(Mode.Pattern))
case _ =>
}
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11 changes: 11 additions & 0 deletions tests/pos/i1737.scala
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Original file line number Diff line number Diff line change
@@ -0,0 +1,11 @@
object Test {
sealed trait Foo[A]
case object FooI extends Foo[Int]
case class FooS(b: Boolean) extends Foo[String]

def algFoo[A](foo: Foo[A]): A =
foo match {
case FooI => 42
case FooS(b) => "foo"
}
}