Rewritten captured type approximation test

Approximation bounds may be non-trivial both (in this case we ignore 'in' projection);
no need for special interpretation of 'Nothing?'

compiler/testData/capturedTypeApproximation/contravariant.kt

@@ -1,11 +0,0 @@
-class Contr<in T>
-
-fun foo<T>(a: Contr<T>) {}
-
-// T captures 'in Int'
-// lower: Contr<Any?>
-// upper: Contr<Int>
-
-// T captures 'out Int'
-// lower: Contr<Int>
-// upper: Contr<Nothing>

compiler/testData/capturedTypeApproximation/covariant.kt

@@ -1,11 +0,0 @@
-class Cov<out T>
-
-fun foo<T>(a: Cov<T>) {}
-
-// T captures 'in Int'
-// lower: Cov<Int>
-// upper: Cov<Any?>
-
-// T captures 'out Int'
-// lower: Cov<Nothing>
-// upper: Cov<Int>

compiler/testData/capturedTypeApproximation/declarations.kt

@@ -0,0 +1,10 @@
+// declarations
+
+class Inv<T>
+class Out<out T>
+class In<in T>
+
+class Inv2<T, R>
+class Fun<in T, out R>
+
+fun <T, R> foo(): #TestType# = throw Exception()

compiler/testData/capturedTypeApproximation/invariant.kt

@@ -1,11 +0,0 @@
-class Inv<T>
-
-fun foo<T>(a: Inv<T>) {}
-
-// T captures 'in Int'
-// lower: Nothing
-// upper: Inv<in Int>
-
-// T captures 'out Int'
-// lower: Nothing
-// upper: Inv<out Int>

compiler/testData/capturedTypeApproximation/nestedCov.kt

@@ -1,12 +0,0 @@
-class Cov<out T>
-class Inv<T>
-
-fun foo<T>(a: Cov<Inv<T>>) {}
-
-// T captures 'in Int'
-// lower: Cov<Nothing>
-// upper: Cov<Inv<in Int>>
-
-// T captures 'out Int'
-// lower: Cov<Nothing>
-// upper: Cov<Inv<out Int>>

compiler/testData/capturedTypeApproximation/nestedInv.kt

@@ -1,11 +0,0 @@
-class Inv<T>
-
-fun foo<T>(a: Inv<Inv<T>>) {}
-
-// T captures 'in Int'
-// lower: Nothing
-// upper: Inv<out Inv<in Int>>
-
-// T captures 'out Int'
-// lower: Nothing
-// upper: Inv<out Inv<out Int>>

compiler/testData/capturedTypeApproximation/nestedInvLevel2.kt

@@ -1,11 +0,0 @@
-class Inv<T>
-
-fun foo<T>(a: Inv<Inv<Inv<T>>>) {}
-
-// T captures 'in Int'
-// lower: Nothing
-// upper: Inv<out Inv<out Inv<in Int>>>
-
-// T captures 'out Int'
-// lower: Nothing
-// upper: Inv<out Inv<out Inv<out Int>>>

compiler/testData/capturedTypeApproximation/nullableT.txt

@@ -0,0 +1,279 @@
+In<T?>
+  in Int. lower: In<Any?>; upper: In<Int?>; substitution: In<Int?>
+  out Int. lower: In<Int?>; upper: In<Nothing?>; substitution: In<out Any?>
+
+Out<T?>
+  in Int. lower: Out<Int?>; upper: Out<Any?>; substitution: Out<Any?>
+  out Int. lower: Out<Nothing?>; upper: Out<Int?>; substitution: Out<Int?>
+
+Inv<T?>
+  in Int. lower: Nothing; upper: Inv<in Int?>; substitution: Inv<in Int?>
+  out Int. lower: Nothing; upper: Inv<out Int?>; substitution: Inv<out Int?>
+
+Inv<in T?>
+  in Int. lower: Inv<Any?>; upper: Inv<in Int?>; substitution: Inv<in Int?>
+  out Int. lower: Inv<in Int?>; upper: Inv<in Nothing?>; substitution: Inv<in Int?>
+
+Inv<out T?>
+  in Int. lower: Inv<out Int?>; upper: Inv<out Any?>; substitution: Inv<out Int?>
+  out Int. lower: Inv<out Nothing?>; upper: Inv<out Int?>; substitution: Inv<out Int?>
+
+In<In<T?>>
+  in Int. lower: In<In<Int?>>; upper: In<In<Any?>>; substitution: In<In<Int?>>
+  out Int. lower: In<In<Nothing?>>; upper: In<In<Int?>>; substitution: In<In<out Any?>>
+
+In<Out<T?>>
+  in Int. lower: In<Out<Any?>>; upper: In<Out<Int?>>; substitution: In<Out<Any?>>
+  out Int. lower: In<Out<Int?>>; upper: In<Out<Nothing?>>; substitution: In<Out<Int?>>
+
+In<Inv<T?>>
+  in Int. lower: In<Inv<in Int?>>; upper: In<Nothing>; substitution: In<Inv<in Int?>>
+  out Int. lower: In<Inv<out Int?>>; upper: In<Nothing>; substitution: In<Inv<out Int?>>
+
+In<Inv<in T?>>
+  in Int. lower: In<Inv<in Int?>>; upper: In<Inv<Any?>>; substitution: In<Inv<in Int?>>
+  out Int. lower: In<Inv<in Nothing?>>; upper: In<Inv<in Int?>>; substitution: In<Inv<in Int?>>
+
+In<Inv<out T?>>
+  in Int. lower: In<Inv<out Any?>>; upper: In<Inv<out Int?>>; substitution: In<Inv<out Int?>>
+  out Int. lower: In<Inv<out Int?>>; upper: In<Inv<out Nothing?>>; substitution: In<Inv<out Int?>>
+
+Out<In<T?>>
+  in Int. lower: Out<In<Any?>>; upper: Out<In<Int?>>; substitution: Out<In<Int?>>
+  out Int. lower: Out<In<Int?>>; upper: Out<In<Nothing?>>; substitution: Out<In<out Any?>>
+
+Out<Out<T?>>
+  in Int. lower: Out<Out<Int?>>; upper: Out<Out<Any?>>; substitution: Out<Out<Any?>>
+  out Int. lower: Out<Out<Nothing?>>; upper: Out<Out<Int?>>; substitution: Out<Out<Int?>>
+
+Out<Inv<T?>>
+  in Int. lower: Out<Nothing>; upper: Out<Inv<in Int?>>; substitution: Out<Inv<in Int?>>
+  out Int. lower: Out<Nothing>; upper: Out<Inv<out Int?>>; substitution: Out<Inv<out Int?>>
+
+Out<Inv<in T?>>
+  in Int. lower: Out<Inv<Any?>>; upper: Out<Inv<in Int?>>; substitution: Out<Inv<in Int?>>
+  out Int. lower: Out<Inv<in Int?>>; upper: Out<Inv<in Nothing?>>; substitution: Out<Inv<in Int?>>
+
+Out<Inv<out T?>>
+  in Int. lower: Out<Inv<out Int?>>; upper: Out<Inv<out Any?>>; substitution: Out<Inv<out Int?>>
+  out Int. lower: Out<Inv<out Nothing?>>; upper: Out<Inv<out Int?>>; substitution: Out<Inv<out Int?>>
+
+Inv<In<T?>>
+  in Int. lower: Nothing; upper: Inv<out In<Int?>>; substitution: Inv<In<Int?>>
+  out Int. lower: Nothing; upper: Inv<out In<Nothing?>>; substitution: Inv<In<out Any?>>
+
+Inv<Out<T?>>
+  in Int. lower: Nothing; upper: Inv<out Out<Any?>>; substitution: Inv<Out<Any?>>
+  out Int. lower: Nothing; upper: Inv<out Out<Int?>>; substitution: Inv<Out<Int?>>
+
+Inv<Inv<T?>>
+  in Int. lower: Nothing; upper: Inv<out Inv<in Int?>>; substitution: Inv<Inv<in Int?>>
+  out Int. lower: Nothing; upper: Inv<out Inv<out Int?>>; substitution: Inv<Inv<out Int?>>
+
+Inv<Inv<in T?>>
+  in Int. lower: Nothing; upper: Inv<out Inv<in Int?>>; substitution: Inv<Inv<in Int?>>
+  out Int. lower: Nothing; upper: Inv<out Inv<in Nothing?>>; substitution: Inv<Inv<in Int?>>
+
+Inv<Inv<out T?>>
+  in Int. lower: Nothing; upper: Inv<out Inv<out Any?>>; substitution: Inv<Inv<out Int?>>
+  out Int. lower: Nothing; upper: Inv<out Inv<out Int?>>; substitution: Inv<Inv<out Int?>>
+
+Inv<in In<T?>>
+  in Int. lower: Inv<in In<Int?>>; upper: Inv<in In<Any?>>; substitution: Inv<in In<Int?>>
+  out Int. lower: Inv<in In<Nothing?>>; upper: Inv<in In<Int?>>; substitution: Inv<in In<out Any?>>
+
+Inv<in Out<T?>>
+  in Int. lower: Inv<in Out<Any?>>; upper: Inv<in Out<Int?>>; substitution: Inv<in Out<Any?>>
+  out Int. lower: Inv<in Out<Int?>>; upper: Inv<in Out<Nothing?>>; substitution: Inv<in Out<Int?>>
+
+Inv<in Inv<T?>>
+  in Int. lower: Inv<in Inv<in Int?>>; upper: Inv<out Any?>; substitution: Inv<in Inv<in Int?>>
+  out Int. lower: Inv<in Inv<out Int?>>; upper: Inv<out Any?>; substitution: Inv<in Inv<out Int?>>
+
+Inv<in Inv<in T?>>
+  in Int. lower: Inv<in Inv<in Int?>>; upper: Inv<in Inv<Any?>>; substitution: Inv<in Inv<in Int?>>
+  out Int. lower: Inv<in Inv<in Nothing?>>; upper: Inv<in Inv<in Int?>>; substitution: Inv<in Inv<in Int?>>
+
+Inv<in Inv<out T?>>
+  in Int. lower: Inv<in Inv<out Any?>>; upper: Inv<in Inv<out Int?>>; substitution: Inv<in Inv<out Int?>>
+  out Int. lower: Inv<in Inv<out Int?>>; upper: Inv<in Inv<out Nothing?>>; substitution: Inv<in Inv<out Int?>>
+
+Inv<out In<T?>>
+  in Int. lower: Inv<out In<Any?>>; upper: Inv<out In<Int?>>; substitution: Inv<out In<Int?>>
+  out Int. lower: Inv<out In<Int?>>; upper: Inv<out In<Nothing?>>; substitution: Inv<out In<out Any?>>
+
+Inv<out Out<T?>>
+  in Int. lower: Inv<out Out<Int?>>; upper: Inv<out Out<Any?>>; substitution: Inv<out Out<Any?>>
+  out Int. lower: Inv<out Out<Nothing?>>; upper: Inv<out Out<Int?>>; substitution: Inv<out Out<Int?>>
+
+Inv<out Inv<T?>>
+  in Int. lower: Inv<Nothing>; upper: Inv<out Inv<in Int?>>; substitution: Inv<out Inv<in Int?>>
+  out Int. lower: Inv<Nothing>; upper: Inv<out Inv<out Int?>>; substitution: Inv<out Inv<out Int?>>
+
+Inv<out Inv<in T?>>
+  in Int. lower: Inv<out Inv<Any?>>; upper: Inv<out Inv<in Int?>>; substitution: Inv<out Inv<in Int?>>
+  out Int. lower: Inv<out Inv<in Int?>>; upper: Inv<out Inv<in Nothing?>>; substitution: Inv<out Inv<in Int?>>
+
+Inv<out Inv<out T?>>
+  in Int. lower: Inv<out Inv<out Int?>>; upper: Inv<out Inv<out Any?>>; substitution: Inv<out Inv<out Int?>>
+  out Int. lower: Inv<out Inv<out Nothing?>>; upper: Inv<out Inv<out Int?>>; substitution: Inv<out Inv<out Int?>>
+
+In<Inv<Out<T?>>>
+  in Int. lower: In<Inv<out Out<Any?>>>; upper: In<Nothing>; substitution: In<Inv<Out<Any?>>>
+  out Int. lower: In<Inv<out Out<Int?>>>; upper: In<Nothing>; substitution: In<Inv<Out<Int?>>>
+
+Out<Out<Out<T?>>>
+  in Int. lower: Out<Out<Out<Int?>>>; upper: Out<Out<Out<Any?>>>; substitution: Out<Out<Out<Any?>>>
+  out Int. lower: Out<Out<Out<Nothing?>>>; upper: Out<Out<Out<Int?>>>; substitution: Out<Out<Out<Int?>>>
+
+Inv<Inv<in In<T?>>>
+  in Int. lower: Nothing; upper: Inv<out Inv<in In<Any?>>>; substitution: Inv<Inv<in In<Int?>>>
+  out Int. lower: Nothing; upper: Inv<out Inv<in In<Int?>>>; substitution: Inv<Inv<in In<out Any?>>>
+
+Inv<out Inv<Out<T?>>>
+  in Int. lower: Inv<Nothing>; upper: Inv<out Inv<out Out<Any?>>>; substitution: Inv<out Inv<Out<Any?>>>
+  out Int. lower: Inv<Nothing>; upper: Inv<out Inv<out Out<Int?>>>; substitution: Inv<out Inv<Out<Int?>>>
+
+Inv<in Inv<Inv<T?>>>
+  in Int. lower: Inv<in Inv<out Inv<in Int?>>>; upper: Inv<out Any?>; substitution: Inv<in Inv<Inv<in Int?>>>
+  out Int. lower: Inv<in Inv<out Inv<out Int?>>>; upper: Inv<out Any?>; substitution: Inv<in Inv<Inv<out Int?>>>
+
+Out<Inv<In<T?>>>
+  in Int. lower: Out<Nothing>; upper: Out<Inv<out In<Int?>>>; substitution: Out<Inv<In<Int?>>>
+  out Int. lower: Out<Nothing>; upper: Out<Inv<out In<Nothing?>>>; substitution: Out<Inv<In<out Any?>>>
+
+Inv<out Out<Out<T?>>>
+  in Int. lower: Inv<out Out<Out<Int?>>>; upper: Inv<out Out<Out<Any?>>>; substitution: Inv<out Out<Out<Any?>>>
+  out Int. lower: Inv<out Out<Out<Nothing?>>>; upper: Inv<out Out<Out<Int?>>>; substitution: Inv<out Out<Out<Int?>>>
+
+Out<In<Inv<T?>>>
+  in Int. lower: Out<In<Inv<in Int?>>>; upper: Out<In<Nothing>>; substitution: Out<In<Inv<in Int?>>>
+  out Int. lower: Out<In<Inv<out Int?>>>; upper: Out<In<Nothing>>; substitution: Out<In<Inv<out Int?>>>
+
+Inv<out In<Out<T?>>>
+  in Int. lower: Inv<out In<Out<Any?>>>; upper: Inv<out In<Out<Int?>>>; substitution: Inv<out In<Out<Any?>>>
+  out Int. lower: Inv<out In<Out<Int?>>>; upper: Inv<out In<Out<Nothing?>>>; substitution: Inv<out In<Out<Int?>>>
+
+In<Out<Inv<T?>>>
+  in Int. lower: In<Out<Inv<in Int?>>>; upper: In<Out<Nothing>>; substitution: In<Out<Inv<in Int?>>>
+  out Int. lower: In<Out<Inv<out Int?>>>; upper: In<Out<Nothing>>; substitution: In<Out<Inv<out Int?>>>
+
+Inv<out Inv<Inv<out Inv<in T?>>>>
+  in Int. lower: Inv<Nothing>; upper: Inv<out Inv<out Inv<out Inv<in Int?>>>>; substitution: Inv<out Inv<Inv<out Inv<in Int?>>>>
+  out Int. lower: Inv<Nothing>; upper: Inv<out Inv<out Inv<out Inv<in Nothing?>>>>; substitution: Inv<out Inv<Inv<out Inv<in Int?>>>>
+
+Inv<in Out<In<Inv<in T?>>>>
+  in Int. lower: Inv<in Out<In<Inv<Any?>>>>; upper: Inv<in Out<In<Inv<in Int?>>>>; substitution: Inv<in Out<In<Inv<in Int?>>>>
+  out Int. lower: Inv<in Out<In<Inv<in Int?>>>>; upper: Inv<in Out<In<Inv<in Nothing?>>>>; substitution: Inv<in Out<In<Inv<in Int?>>>>
+
+Inv<in In<Inv<out Inv<in T?>>>>
+  in Int. lower: Inv<in In<Inv<out Inv<Any?>>>>; upper: Inv<in In<Inv<out Inv<in Int?>>>>; substitution: Inv<in In<Inv<out Inv<in Int?>>>>
+  out Int. lower: Inv<in In<Inv<out Inv<in Int?>>>>; upper: Inv<in In<Inv<out Inv<in Nothing?>>>>; substitution: Inv<in In<Inv<out Inv<in Int?>>>>
+
+Inv<In<In<Inv<in T?>>>>
+  in Int. lower: Nothing; upper: Inv<out In<In<Inv<in Int?>>>>; substitution: Inv<In<In<Inv<in Int?>>>>
+  out Int. lower: Nothing; upper: Inv<out In<In<Inv<in Nothing?>>>>; substitution: Inv<In<In<Inv<in Int?>>>>
+
+Inv<out Inv<out Inv<out Inv<T?>>>>
+  in Int. lower: Inv<out Inv<out Inv<Nothing>>>; upper: Inv<out Inv<out Inv<out Inv<in Int?>>>>; substitution: Inv<out Inv<out Inv<out Inv<in Int?>>>>
+  out Int. lower: Inv<out Inv<out Inv<Nothing>>>; upper: Inv<out Inv<out Inv<out Inv<out Int?>>>>; substitution: Inv<out Inv<out Inv<out Inv<out Int?>>>>
+
+Inv<out Out<Inv<out Inv<in T?>>>>
+  in Int. lower: Inv<out Out<Inv<out Inv<Any?>>>>; upper: Inv<out Out<Inv<out Inv<in Int?>>>>; substitution: Inv<out Out<Inv<out Inv<in Int?>>>>
+  out Int. lower: Inv<out Out<Inv<out Inv<in Int?>>>>; upper: Inv<out Out<Inv<out Inv<in Nothing?>>>>; substitution: Inv<out Out<Inv<out Inv<in Int?>>>>
+
+Out<Inv<out Inv<out In<T?>>>>
+  in Int. lower: Out<Inv<out Inv<out In<Any?>>>>; upper: Out<Inv<out Inv<out In<Int?>>>>; substitution: Out<Inv<out Inv<out In<Int?>>>>
+  out Int. lower: Out<Inv<out Inv<out In<Int?>>>>; upper: Out<Inv<out Inv<out In<Nothing?>>>>; substitution: Out<Inv<out Inv<out In<out Any?>>>>
+
+In<Inv<in In<Inv<in T?>>>>
+  in Int. lower: In<Inv<in In<Inv<in Int?>>>>; upper: In<Inv<in In<Inv<Any?>>>>; substitution: In<Inv<in In<Inv<in Int?>>>>
+  out Int. lower: In<Inv<in In<Inv<in Nothing?>>>>; upper: In<Inv<in In<Inv<in Int?>>>>; substitution: In<Inv<in In<Inv<in Int?>>>>
+
+Out<Inv<in In<Inv<T?>>>>
+  in Int. lower: Out<Inv<in In<Nothing>>>; upper: Out<Inv<in In<Inv<in Int?>>>>; substitution: Out<Inv<in In<Inv<in Int?>>>>
+  out Int. lower: Out<Inv<in In<Nothing>>>; upper: Out<Inv<in In<Inv<out Int?>>>>; substitution: Out<Inv<in In<Inv<out Int?>>>>
+
+Out<Inv<in Inv<in Inv<T?>>>>
+  in Int. lower: Out<Inv<in Inv<out Any?>>>; upper: Out<Inv<in Inv<in Inv<in Int?>>>>; substitution: Out<Inv<in Inv<in Inv<in Int?>>>>
+  out Int. lower: Out<Inv<in Inv<out Any?>>>; upper: Out<Inv<in Inv<in Inv<out Int?>>>>; substitution: Out<Inv<in Inv<in Inv<out Int?>>>>
+
+In<In<Inv<In<In<T?>>>>>
+  in Int. lower: In<In<Nothing>>; upper: In<In<Inv<out In<In<Any?>>>>>; substitution: In<In<Inv<In<In<Int?>>>>>
+  out Int. lower: In<In<Nothing>>; upper: In<In<Inv<out In<In<Int?>>>>>; substitution: In<In<Inv<In<In<out Any?>>>>>
+
+Inv<Inv<Inv<Out<Inv<in T?>>>>>
+  in Int. lower: Nothing; upper: Inv<out Inv<out Inv<out Out<Inv<in Int?>>>>>; substitution: Inv<Inv<Inv<Out<Inv<in Int?>>>>>
+  out Int. lower: Nothing; upper: Inv<out Inv<out Inv<out Out<Inv<in Nothing?>>>>>; substitution: Inv<Inv<Inv<Out<Inv<in Int?>>>>>
+
+Out<Inv<Out<Out<Inv<out T?>>>>>
+  in Int. lower: Out<Nothing>; upper: Out<Inv<out Out<Out<Inv<out Any?>>>>>; substitution: Out<Inv<Out<Out<Inv<out Int?>>>>>
+  out Int. lower: Out<Nothing>; upper: Out<Inv<out Out<Out<Inv<out Int?>>>>>; substitution: Out<Inv<Out<Out<Inv<out Int?>>>>>
+
+Inv<In<Inv<in In<Inv<out T?>>>>>
+  in Int. lower: Nothing; upper: Inv<out In<Inv<in In<Inv<out Int?>>>>>; substitution: Inv<In<Inv<in In<Inv<out Int?>>>>>
+  out Int. lower: Nothing; upper: Inv<out In<Inv<in In<Inv<out Nothing?>>>>>; substitution: Inv<In<Inv<in In<Inv<out Int?>>>>>
+
+Inv<in Inv<out In<Out<Inv<out T?>>>>>
+  in Int. lower: Inv<in Inv<out In<Out<Inv<out Int?>>>>>; upper: Inv<in Inv<out In<Out<Inv<out Any?>>>>>; substitution: Inv<in Inv<out In<Out<Inv<out Int?>>>>>
+  out Int. lower: Inv<in Inv<out In<Out<Inv<out Nothing?>>>>>; upper: Inv<in Inv<out In<Out<Inv<out Int?>>>>>; substitution: Inv<in Inv<out In<Out<Inv<out Int?>>>>>
+
+Inv<out Out<Inv<in Inv<in Inv<in T?>>>>>
+  in Int. lower: Inv<out Out<Inv<in Inv<in Inv<Any?>>>>>; upper: Inv<out Out<Inv<in Inv<in Inv<in Int?>>>>>; substitution: Inv<out Out<Inv<in Inv<in Inv<in Int?>>>>>
+  out Int. lower: Inv<out Out<Inv<in Inv<in Inv<in Int?>>>>>; upper: Inv<out Out<Inv<in Inv<in Inv<in Nothing?>>>>>; substitution: Inv<out Out<Inv<in Inv<in Inv<in Int?>>>>>
+
+Out<Out<Inv<Out<Inv<out T?>>>>>
+  in Int. lower: Out<Out<Nothing>>; upper: Out<Out<Inv<out Out<Inv<out Any?>>>>>; substitution: Out<Out<Inv<Out<Inv<out Int?>>>>>
+  out Int. lower: Out<Out<Nothing>>; upper: Out<Out<Inv<out Out<Inv<out Int?>>>>>; substitution: Out<Out<Inv<Out<Inv<out Int?>>>>>
+
+In<Inv<In<In<Inv<out T?>>>>>
+  in Int. lower: In<Inv<out In<In<Inv<out Any?>>>>>; upper: In<Nothing>; substitution: In<Inv<In<In<Inv<out Int?>>>>>
+  out Int. lower: In<Inv<out In<In<Inv<out Int?>>>>>; upper: In<Nothing>; substitution: In<Inv<In<In<Inv<out Int?>>>>>
+
+Inv<out Inv<in Inv<Inv<out Inv<out T?>>>>>
+  in Int. lower: Inv<out Inv<in Inv<out Inv<out Inv<out Any?>>>>>; upper: Inv<out Inv<out Any?>>; substitution: Inv<out Inv<in Inv<Inv<out Inv<out Int?>>>>>
+  out Int. lower: Inv<out Inv<in Inv<out Inv<out Inv<out Int?>>>>>; upper: Inv<out Inv<out Any?>>; substitution: Inv<out Inv<in Inv<Inv<out Inv<out Int?>>>>>
+
+In<Inv<in In<In<Inv<out T?>>>>>
+  in Int. lower: In<Inv<in In<In<Inv<out Int?>>>>>; upper: In<Inv<in In<In<Inv<out Any?>>>>>; substitution: In<Inv<in In<In<Inv<out Int?>>>>>
+  out Int. lower: In<Inv<in In<In<Inv<out Nothing?>>>>>; upper: In<Inv<in In<In<Inv<out Int?>>>>>; substitution: In<Inv<in In<In<Inv<out Int?>>>>>
+
+In<Inv<Out<In<Inv<Inv<T?>>>>>>
+  in Int. lower: In<Inv<out Out<In<Nothing>>>>; upper: In<Nothing>; substitution: In<Inv<Out<In<Inv<Inv<in Int?>>>>>>
+  out Int. lower: In<Inv<out Out<In<Nothing>>>>; upper: In<Nothing>; substitution: In<Inv<Out<In<Inv<Inv<out Int?>>>>>>
+
+Out<Inv<Inv<out Inv<Inv<in In<T?>>>>>>
+  in Int. lower: Out<Nothing>; upper: Out<Inv<out Inv<out Inv<out Inv<in In<Any?>>>>>>; substitution: Out<Inv<Inv<out Inv<Inv<in In<Int?>>>>>>
+  out Int. lower: Out<Nothing>; upper: Out<Inv<out Inv<out Inv<out Inv<in In<Int?>>>>>>; substitution: Out<Inv<Inv<out Inv<Inv<in In<out Any?>>>>>>
+
+Inv<Out<In<In<Inv<in In<T?>>>>>>
+  in Int. lower: Nothing; upper: Inv<out Out<In<In<Inv<in In<Any?>>>>>>; substitution: Inv<Out<In<In<Inv<in In<Int?>>>>>>
+  out Int. lower: Nothing; upper: Inv<out Out<In<In<Inv<in In<Int?>>>>>>; substitution: Inv<Out<In<In<Inv<in In<out Any?>>>>>>
+
+Inv<In<Inv<Inv<in Inv<out Inv<out T?>>>>>>
+  in Int. lower: Nothing; upper: Inv<out In<Nothing>>; substitution: Inv<In<Inv<Inv<in Inv<out Inv<out Int?>>>>>>
+  out Int. lower: Nothing; upper: Inv<out In<Nothing>>; substitution: Inv<In<Inv<Inv<in Inv<out Inv<out Int?>>>>>>
+
+In<Inv<out Inv<in Inv<Inv<in Inv<out T?>>>>>>
+  in Int. lower: In<Inv<out Inv<out Any?>>>; upper: In<Inv<out Inv<in Inv<out Inv<in Inv<out Int?>>>>>>; substitution: In<Inv<out Inv<in Inv<Inv<in Inv<out Int?>>>>>>
+  out Int. lower: In<Inv<out Inv<out Any?>>>; upper: In<Inv<out Inv<in Inv<out Inv<in Inv<out Nothing?>>>>>>; substitution: In<Inv<out Inv<in Inv<Inv<in Inv<out Int?>>>>>>
+
+In<Inv<Inv<out Inv<out In<In<T?>>>>>>
+  in Int. lower: In<Inv<out Inv<out Inv<out In<In<Any?>>>>>>; upper: In<Nothing>; substitution: In<Inv<Inv<out Inv<out In<In<Int?>>>>>>
+  out Int. lower: In<Inv<out Inv<out Inv<out In<In<Int?>>>>>>; upper: In<Nothing>; substitution: In<Inv<Inv<out Inv<out In<In<out Any?>>>>>>
+
+Out<In<Inv<Out<Inv<Out<T?>>>>>>
+  in Int. lower: Out<In<Inv<out Out<Inv<out Out<Any?>>>>>>; upper: Out<In<Nothing>>; substitution: Out<In<Inv<Out<Inv<Out<Any?>>>>>>
+  out Int. lower: Out<In<Inv<out Out<Inv<out Out<Int?>>>>>>; upper: Out<In<Nothing>>; substitution: Out<In<Inv<Out<Inv<Out<Int?>>>>>>
+
+Inv<out Inv<Inv<in Out<Inv<out Inv<in T?>>>>>>
+  in Int. lower: Inv<Nothing>; upper: Inv<out Inv<out Inv<in Out<Inv<out Inv<Any?>>>>>>; substitution: Inv<out Inv<Inv<in Out<Inv<out Inv<in Int?>>>>>>
+  out Int. lower: Inv<Nothing>; upper: Inv<out Inv<out Inv<in Out<Inv<out Inv<in Int?>>>>>>; substitution: Inv<out Inv<Inv<in Out<Inv<out Inv<in Int?>>>>>>
+
+Out<Inv<in Inv<Out<Inv<Out<T?>>>>>>
+  in Int. lower: Out<Inv<in Inv<out Out<Inv<out Out<Any?>>>>>>; upper: Out<Inv<out Any?>>; substitution: Out<Inv<in Inv<Out<Inv<Out<Any?>>>>>>
+  out Int. lower: Out<Inv<in Inv<out Out<Inv<out Out<Int?>>>>>>; upper: Out<Inv<out Any?>>; substitution: Out<Inv<in Inv<Out<Inv<Out<Int?>>>>>>
+
+Inv<Inv<in Inv<in In<In<Out<T?>>>>>>
+  in Int. lower: Nothing; upper: Inv<out Inv<in Inv<in In<In<Out<Any?>>>>>>; substitution: Inv<Inv<in Inv<in In<In<Out<Any?>>>>>>
+  out Int. lower: Nothing; upper: Inv<out Inv<in Inv<in In<In<Out<Int?>>>>>>; substitution: Inv<Inv<in Inv<in In<In<Out<Int?>>>>>>

compiler/testData/capturedTypeApproximation/nullableTypeVariable.kt

@@ -1,11 +0,0 @@
-class Inv<T>
-
-fun foo<T>(a: Inv<T?>) {}
-
-// T captures 'in Int'
-// lower: Nothing
-// upper: Inv<in Int?>
-
-// T captures 'out Int'
-// lower: Nothing
-// upper: Inv<out Int?>

compiler/testData/capturedTypeApproximation/simpleT.txt

@@ -0,0 +1,279 @@
+In<T>
+  in Int. lower: In<Any?>; upper: In<Int>; substitution: In<Int>
+  out Int. lower: In<Int>; upper: In<Nothing>; substitution: In<out Any?>
+
+Out<T>
+  in Int. lower: Out<Int>; upper: Out<Any?>; substitution: Out<Any?>
+  out Int. lower: Out<Nothing>; upper: Out<Int>; substitution: Out<Int>
+
+Inv<T>
+  in Int. lower: Nothing; upper: Inv<in Int>; substitution: Inv<in Int>
+  out Int. lower: Nothing; upper: Inv<out Int>; substitution: Inv<out Int>
+
+Inv<in T>
+  in Int. lower: Inv<Any?>; upper: Inv<in Int>; substitution: Inv<in Int>
+  out Int. lower: Inv<in Int>; upper: Inv<out Any?>; substitution: Inv<in Int>
+
+Inv<out T>
+  in Int. lower: Inv<out Int>; upper: Inv<out Any?>; substitution: Inv<out Int>
+  out Int. lower: Inv<Nothing>; upper: Inv<out Int>; substitution: Inv<out Int>
+
+In<In<T>>
+  in Int. lower: In<In<Int>>; upper: In<In<Any?>>; substitution: In<In<Int>>
+  out Int. lower: In<In<Nothing>>; upper: In<In<Int>>; substitution: In<In<out Any?>>
+
+In<Out<T>>
+  in Int. lower: In<Out<Any?>>; upper: In<Out<Int>>; substitution: In<Out<Any?>>
+  out Int. lower: In<Out<Int>>; upper: In<Out<Nothing>>; substitution: In<Out<Int>>
+
+In<Inv<T>>
+  in Int. lower: In<Inv<in Int>>; upper: In<Nothing>; substitution: In<Inv<in Int>>
+  out Int. lower: In<Inv<out Int>>; upper: In<Nothing>; substitution: In<Inv<out Int>>
+
+In<Inv<in T>>
+  in Int. lower: In<Inv<in Int>>; upper: In<Inv<Any?>>; substitution: In<Inv<in Int>>
+  out Int. lower: In<Inv<out Any?>>; upper: In<Inv<in Int>>; substitution: In<Inv<in Int>>
+
+In<Inv<out T>>
+  in Int. lower: In<Inv<out Any?>>; upper: In<Inv<out Int>>; substitution: In<Inv<out Int>>
+  out Int. lower: In<Inv<out Int>>; upper: In<Inv<Nothing>>; substitution: In<Inv<out Int>>
+
+Out<In<T>>
+  in Int. lower: Out<In<Any?>>; upper: Out<In<Int>>; substitution: Out<In<Int>>
+  out Int. lower: Out<In<Int>>; upper: Out<In<Nothing>>; substitution: Out<In<out Any?>>
+
+Out<Out<T>>
+  in Int. lower: Out<Out<Int>>; upper: Out<Out<Any?>>; substitution: Out<Out<Any?>>
+  out Int. lower: Out<Out<Nothing>>; upper: Out<Out<Int>>; substitution: Out<Out<Int>>
+
+Out<Inv<T>>
+  in Int. lower: Out<Nothing>; upper: Out<Inv<in Int>>; substitution: Out<Inv<in Int>>
+  out Int. lower: Out<Nothing>; upper: Out<Inv<out Int>>; substitution: Out<Inv<out Int>>
+
+Out<Inv<in T>>
+  in Int. lower: Out<Inv<Any?>>; upper: Out<Inv<in Int>>; substitution: Out<Inv<in Int>>
+  out Int. lower: Out<Inv<in Int>>; upper: Out<Inv<out Any?>>; substitution: Out<Inv<in Int>>
+
+Out<Inv<out T>>
+  in Int. lower: Out<Inv<out Int>>; upper: Out<Inv<out Any?>>; substitution: Out<Inv<out Int>>
+  out Int. lower: Out<Inv<Nothing>>; upper: Out<Inv<out Int>>; substitution: Out<Inv<out Int>>
+
+Inv<In<T>>
+  in Int. lower: Nothing; upper: Inv<out In<Int>>; substitution: Inv<In<Int>>
+  out Int. lower: Nothing; upper: Inv<out In<Nothing>>; substitution: Inv<In<out Any?>>
+
+Inv<Out<T>>
+  in Int. lower: Nothing; upper: Inv<out Out<Any?>>; substitution: Inv<Out<Any?>>
+  out Int. lower: Nothing; upper: Inv<out Out<Int>>; substitution: Inv<Out<Int>>
+
+Inv<Inv<T>>
+  in Int. lower: Nothing; upper: Inv<out Inv<in Int>>; substitution: Inv<Inv<in Int>>
+  out Int. lower: Nothing; upper: Inv<out Inv<out Int>>; substitution: Inv<Inv<out Int>>
+
+Inv<Inv<in T>>
+  in Int. lower: Nothing; upper: Inv<out Inv<in Int>>; substitution: Inv<Inv<in Int>>
+  out Int. lower: Nothing; upper: Inv<out Inv<out Any?>>; substitution: Inv<Inv<in Int>>
+
+Inv<Inv<out T>>
+  in Int. lower: Nothing; upper: Inv<out Inv<out Any?>>; substitution: Inv<Inv<out Int>>
+  out Int. lower: Nothing; upper: Inv<out Inv<out Int>>; substitution: Inv<Inv<out Int>>
+
+Inv<in In<T>>
+  in Int. lower: Inv<in In<Int>>; upper: Inv<in In<Any?>>; substitution: Inv<in In<Int>>
+  out Int. lower: Inv<in In<Nothing>>; upper: Inv<in In<Int>>; substitution: Inv<in In<out Any?>>
+
+Inv<in Out<T>>
+  in Int. lower: Inv<in Out<Any?>>; upper: Inv<in Out<Int>>; substitution: Inv<in Out<Any?>>
+  out Int. lower: Inv<in Out<Int>>; upper: Inv<in Out<Nothing>>; substitution: Inv<in Out<Int>>
+
+Inv<in Inv<T>>
+  in Int. lower: Inv<in Inv<in Int>>; upper: Inv<out Any?>; substitution: Inv<in Inv<in Int>>
+  out Int. lower: Inv<in Inv<out Int>>; upper: Inv<out Any?>; substitution: Inv<in Inv<out Int>>
+
+Inv<in Inv<in T>>
+  in Int. lower: Inv<in Inv<in Int>>; upper: Inv<in Inv<Any?>>; substitution: Inv<in Inv<in Int>>
+  out Int. lower: Inv<in Inv<out Any?>>; upper: Inv<in Inv<in Int>>; substitution: Inv<in Inv<in Int>>
+
+Inv<in Inv<out T>>
+  in Int. lower: Inv<in Inv<out Any?>>; upper: Inv<in Inv<out Int>>; substitution: Inv<in Inv<out Int>>
+  out Int. lower: Inv<in Inv<out Int>>; upper: Inv<in Inv<Nothing>>; substitution: Inv<in Inv<out Int>>
+
+Inv<out In<T>>
+  in Int. lower: Inv<out In<Any?>>; upper: Inv<out In<Int>>; substitution: Inv<out In<Int>>
+  out Int. lower: Inv<out In<Int>>; upper: Inv<out In<Nothing>>; substitution: Inv<out In<out Any?>>
+
+Inv<out Out<T>>
+  in Int. lower: Inv<out Out<Int>>; upper: Inv<out Out<Any?>>; substitution: Inv<out Out<Any?>>
+  out Int. lower: Inv<out Out<Nothing>>; upper: Inv<out Out<Int>>; substitution: Inv<out Out<Int>>
+
+Inv<out Inv<T>>
+  in Int. lower: Inv<Nothing>; upper: Inv<out Inv<in Int>>; substitution: Inv<out Inv<in Int>>
+  out Int. lower: Inv<Nothing>; upper: Inv<out Inv<out Int>>; substitution: Inv<out Inv<out Int>>
+
+Inv<out Inv<in T>>
+  in Int. lower: Inv<out Inv<Any?>>; upper: Inv<out Inv<in Int>>; substitution: Inv<out Inv<in Int>>
+  out Int. lower: Inv<out Inv<in Int>>; upper: Inv<out Inv<out Any?>>; substitution: Inv<out Inv<in Int>>
+
+Inv<out Inv<out T>>
+  in Int. lower: Inv<out Inv<out Int>>; upper: Inv<out Inv<out Any?>>; substitution: Inv<out Inv<out Int>>
+  out Int. lower: Inv<out Inv<Nothing>>; upper: Inv<out Inv<out Int>>; substitution: Inv<out Inv<out Int>>
+
+In<Inv<Out<T>>>
+  in Int. lower: In<Inv<out Out<Any?>>>; upper: In<Nothing>; substitution: In<Inv<Out<Any?>>>
+  out Int. lower: In<Inv<out Out<Int>>>; upper: In<Nothing>; substitution: In<Inv<Out<Int>>>
+
+Out<Out<Out<T>>>
+  in Int. lower: Out<Out<Out<Int>>>; upper: Out<Out<Out<Any?>>>; substitution: Out<Out<Out<Any?>>>
+  out Int. lower: Out<Out<Out<Nothing>>>; upper: Out<Out<Out<Int>>>; substitution: Out<Out<Out<Int>>>
+
+Inv<Inv<in In<T>>>
+  in Int. lower: Nothing; upper: Inv<out Inv<in In<Any?>>>; substitution: Inv<Inv<in In<Int>>>
+  out Int. lower: Nothing; upper: Inv<out Inv<in In<Int>>>; substitution: Inv<Inv<in In<out Any?>>>
+
+Inv<out Inv<Out<T>>>
+  in Int. lower: Inv<Nothing>; upper: Inv<out Inv<out Out<Any?>>>; substitution: Inv<out Inv<Out<Any?>>>
+  out Int. lower: Inv<Nothing>; upper: Inv<out Inv<out Out<Int>>>; substitution: Inv<out Inv<Out<Int>>>
+
+Inv<in Inv<Inv<T>>>
+  in Int. lower: Inv<in Inv<out Inv<in Int>>>; upper: Inv<out Any?>; substitution: Inv<in Inv<Inv<in Int>>>
+  out Int. lower: Inv<in Inv<out Inv<out Int>>>; upper: Inv<out Any?>; substitution: Inv<in Inv<Inv<out Int>>>
+
+Out<Inv<In<T>>>
+  in Int. lower: Out<Nothing>; upper: Out<Inv<out In<Int>>>; substitution: Out<Inv<In<Int>>>
+  out Int. lower: Out<Nothing>; upper: Out<Inv<out In<Nothing>>>; substitution: Out<Inv<In<out Any?>>>
+
+Inv<out Out<Out<T>>>
+  in Int. lower: Inv<out Out<Out<Int>>>; upper: Inv<out Out<Out<Any?>>>; substitution: Inv<out Out<Out<Any?>>>
+  out Int. lower: Inv<out Out<Out<Nothing>>>; upper: Inv<out Out<Out<Int>>>; substitution: Inv<out Out<Out<Int>>>
+
+Out<In<Inv<T>>>
+  in Int. lower: Out<In<Inv<in Int>>>; upper: Out<In<Nothing>>; substitution: Out<In<Inv<in Int>>>
+  out Int. lower: Out<In<Inv<out Int>>>; upper: Out<In<Nothing>>; substitution: Out<In<Inv<out Int>>>
+
+Inv<out In<Out<T>>>
+  in Int. lower: Inv<out In<Out<Any?>>>; upper: Inv<out In<Out<Int>>>; substitution: Inv<out In<Out<Any?>>>
+  out Int. lower: Inv<out In<Out<Int>>>; upper: Inv<out In<Out<Nothing>>>; substitution: Inv<out In<Out<Int>>>
+
+In<Out<Inv<T>>>
+  in Int. lower: In<Out<Inv<in Int>>>; upper: In<Out<Nothing>>; substitution: In<Out<Inv<in Int>>>
+  out Int. lower: In<Out<Inv<out Int>>>; upper: In<Out<Nothing>>; substitution: In<Out<Inv<out Int>>>
+
+Inv<out Inv<Inv<out Inv<in T>>>>
+  in Int. lower: Inv<Nothing>; upper: Inv<out Inv<out Inv<out Inv<in Int>>>>; substitution: Inv<out Inv<Inv<out Inv<in Int>>>>
+  out Int. lower: Inv<Nothing>; upper: Inv<out Inv<out Inv<out Inv<out Any?>>>>; substitution: Inv<out Inv<Inv<out Inv<in Int>>>>
+
+Inv<in Out<In<Inv<in T>>>>
+  in Int. lower: Inv<in Out<In<Inv<Any?>>>>; upper: Inv<in Out<In<Inv<in Int>>>>; substitution: Inv<in Out<In<Inv<in Int>>>>
+  out Int. lower: Inv<in Out<In<Inv<in Int>>>>; upper: Inv<in Out<In<Inv<out Any?>>>>; substitution: Inv<in Out<In<Inv<in Int>>>>
+
+Inv<in In<Inv<out Inv<in T>>>>
+  in Int. lower: Inv<in In<Inv<out Inv<Any?>>>>; upper: Inv<in In<Inv<out Inv<in Int>>>>; substitution: Inv<in In<Inv<out Inv<in Int>>>>
+  out Int. lower: Inv<in In<Inv<out Inv<in Int>>>>; upper: Inv<in In<Inv<out Inv<out Any?>>>>; substitution: Inv<in In<Inv<out Inv<in Int>>>>
+
+Inv<In<In<Inv<in T>>>>
+  in Int. lower: Nothing; upper: Inv<out In<In<Inv<in Int>>>>; substitution: Inv<In<In<Inv<in Int>>>>
+  out Int. lower: Nothing; upper: Inv<out In<In<Inv<out Any?>>>>; substitution: Inv<In<In<Inv<in Int>>>>
+
+Inv<out Inv<out Inv<out Inv<T>>>>
+  in Int. lower: Inv<out Inv<out Inv<Nothing>>>; upper: Inv<out Inv<out Inv<out Inv<in Int>>>>; substitution: Inv<out Inv<out Inv<out Inv<in Int>>>>
+  out Int. lower: Inv<out Inv<out Inv<Nothing>>>; upper: Inv<out Inv<out Inv<out Inv<out Int>>>>; substitution: Inv<out Inv<out Inv<out Inv<out Int>>>>
+
+Inv<out Out<Inv<out Inv<in T>>>>
+  in Int. lower: Inv<out Out<Inv<out Inv<Any?>>>>; upper: Inv<out Out<Inv<out Inv<in Int>>>>; substitution: Inv<out Out<Inv<out Inv<in Int>>>>
+  out Int. lower: Inv<out Out<Inv<out Inv<in Int>>>>; upper: Inv<out Out<Inv<out Inv<out Any?>>>>; substitution: Inv<out Out<Inv<out Inv<in Int>>>>
+
+Out<Inv<out Inv<out In<T>>>>
+  in Int. lower: Out<Inv<out Inv<out In<Any?>>>>; upper: Out<Inv<out Inv<out In<Int>>>>; substitution: Out<Inv<out Inv<out In<Int>>>>
+  out Int. lower: Out<Inv<out Inv<out In<Int>>>>; upper: Out<Inv<out Inv<out In<Nothing>>>>; substitution: Out<Inv<out Inv<out In<out Any?>>>>
+
+In<Inv<in In<Inv<in T>>>>
+  in Int. lower: In<Inv<in In<Inv<in Int>>>>; upper: In<Inv<in In<Inv<Any?>>>>; substitution: In<Inv<in In<Inv<in Int>>>>
+  out Int. lower: In<Inv<in In<Inv<out Any?>>>>; upper: In<Inv<in In<Inv<in Int>>>>; substitution: In<Inv<in In<Inv<in Int>>>>
+
+Out<Inv<in In<Inv<T>>>>
+  in Int. lower: Out<Inv<in In<Nothing>>>; upper: Out<Inv<in In<Inv<in Int>>>>; substitution: Out<Inv<in In<Inv<in Int>>>>
+  out Int. lower: Out<Inv<in In<Nothing>>>; upper: Out<Inv<in In<Inv<out Int>>>>; substitution: Out<Inv<in In<Inv<out Int>>>>
+
+Out<Inv<in Inv<in Inv<T>>>>
+  in Int. lower: Out<Inv<in Inv<out Any?>>>; upper: Out<Inv<in Inv<in Inv<in Int>>>>; substitution: Out<Inv<in Inv<in Inv<in Int>>>>
+  out Int. lower: Out<Inv<in Inv<out Any?>>>; upper: Out<Inv<in Inv<in Inv<out Int>>>>; substitution: Out<Inv<in Inv<in Inv<out Int>>>>
+
+In<In<Inv<In<In<T>>>>>
+  in Int. lower: In<In<Nothing>>; upper: In<In<Inv<out In<In<Any?>>>>>; substitution: In<In<Inv<In<In<Int>>>>>
+  out Int. lower: In<In<Nothing>>; upper: In<In<Inv<out In<In<Int>>>>>; substitution: In<In<Inv<In<In<out Any?>>>>>
+
+Inv<Inv<Inv<Out<Inv<in T>>>>>
+  in Int. lower: Nothing; upper: Inv<out Inv<out Inv<out Out<Inv<in Int>>>>>; substitution: Inv<Inv<Inv<Out<Inv<in Int>>>>>
+  out Int. lower: Nothing; upper: Inv<out Inv<out Inv<out Out<Inv<out Any?>>>>>; substitution: Inv<Inv<Inv<Out<Inv<in Int>>>>>
+
+Out<Inv<Out<Out<Inv<out T>>>>>
+  in Int. lower: Out<Nothing>; upper: Out<Inv<out Out<Out<Inv<out Any?>>>>>; substitution: Out<Inv<Out<Out<Inv<out Int>>>>>
+  out Int. lower: Out<Nothing>; upper: Out<Inv<out Out<Out<Inv<out Int>>>>>; substitution: Out<Inv<Out<Out<Inv<out Int>>>>>
+
+Inv<In<Inv<in In<Inv<out T>>>>>
+  in Int. lower: Nothing; upper: Inv<out In<Inv<in In<Inv<out Int>>>>>; substitution: Inv<In<Inv<in In<Inv<out Int>>>>>
+  out Int. lower: Nothing; upper: Inv<out In<Inv<in In<Inv<Nothing>>>>>; substitution: Inv<In<Inv<in In<Inv<out Int>>>>>
+
+Inv<in Inv<out In<Out<Inv<out T>>>>>
+  in Int. lower: Inv<in Inv<out In<Out<Inv<out Int>>>>>; upper: Inv<in Inv<out In<Out<Inv<out Any?>>>>>; substitution: Inv<in Inv<out In<Out<Inv<out Int>>>>>
+  out Int. lower: Inv<in Inv<out In<Out<Inv<Nothing>>>>>; upper: Inv<in Inv<out In<Out<Inv<out Int>>>>>; substitution: Inv<in Inv<out In<Out<Inv<out Int>>>>>
+
+Inv<out Out<Inv<in Inv<in Inv<in T>>>>>
+  in Int. lower: Inv<out Out<Inv<in Inv<in Inv<Any?>>>>>; upper: Inv<out Out<Inv<in Inv<in Inv<in Int>>>>>; substitution: Inv<out Out<Inv<in Inv<in Inv<in Int>>>>>
+  out Int. lower: Inv<out Out<Inv<in Inv<in Inv<in Int>>>>>; upper: Inv<out Out<Inv<in Inv<in Inv<out Any?>>>>>; substitution: Inv<out Out<Inv<in Inv<in Inv<in Int>>>>>
+
+Out<Out<Inv<Out<Inv<out T>>>>>
+  in Int. lower: Out<Out<Nothing>>; upper: Out<Out<Inv<out Out<Inv<out Any?>>>>>; substitution: Out<Out<Inv<Out<Inv<out Int>>>>>
+  out Int. lower: Out<Out<Nothing>>; upper: Out<Out<Inv<out Out<Inv<out Int>>>>>; substitution: Out<Out<Inv<Out<Inv<out Int>>>>>
+
+In<Inv<In<In<Inv<out T>>>>>
+  in Int. lower: In<Inv<out In<In<Inv<out Any?>>>>>; upper: In<Nothing>; substitution: In<Inv<In<In<Inv<out Int>>>>>
+  out Int. lower: In<Inv<out In<In<Inv<out Int>>>>>; upper: In<Nothing>; substitution: In<Inv<In<In<Inv<out Int>>>>>
+
+Inv<out Inv<in Inv<Inv<out Inv<out T>>>>>
+  in Int. lower: Inv<out Inv<in Inv<out Inv<out Inv<out Any?>>>>>; upper: Inv<out Inv<out Any?>>; substitution: Inv<out Inv<in Inv<Inv<out Inv<out Int>>>>>
+  out Int. lower: Inv<out Inv<in Inv<out Inv<out Inv<out Int>>>>>; upper: Inv<out Inv<out Any?>>; substitution: Inv<out Inv<in Inv<Inv<out Inv<out Int>>>>>
+
+In<Inv<in In<In<Inv<out T>>>>>
+  in Int. lower: In<Inv<in In<In<Inv<out Int>>>>>; upper: In<Inv<in In<In<Inv<out Any?>>>>>; substitution: In<Inv<in In<In<Inv<out Int>>>>>
+  out Int. lower: In<Inv<in In<In<Inv<Nothing>>>>>; upper: In<Inv<in In<In<Inv<out Int>>>>>; substitution: In<Inv<in In<In<Inv<out Int>>>>>
+
+In<Inv<Out<In<Inv<Inv<T>>>>>>
+  in Int. lower: In<Inv<out Out<In<Nothing>>>>; upper: In<Nothing>; substitution: In<Inv<Out<In<Inv<Inv<in Int>>>>>>
+  out Int. lower: In<Inv<out Out<In<Nothing>>>>; upper: In<Nothing>; substitution: In<Inv<Out<In<Inv<Inv<out Int>>>>>>
+
+Out<Inv<Inv<out Inv<Inv<in In<T>>>>>>
+  in Int. lower: Out<Nothing>; upper: Out<Inv<out Inv<out Inv<out Inv<in In<Any?>>>>>>; substitution: Out<Inv<Inv<out Inv<Inv<in In<Int>>>>>>
+  out Int. lower: Out<Nothing>; upper: Out<Inv<out Inv<out Inv<out Inv<in In<Int>>>>>>; substitution: Out<Inv<Inv<out Inv<Inv<in In<out Any?>>>>>>
+
+Inv<Out<In<In<Inv<in In<T>>>>>>
+  in Int. lower: Nothing; upper: Inv<out Out<In<In<Inv<in In<Any?>>>>>>; substitution: Inv<Out<In<In<Inv<in In<Int>>>>>>
+  out Int. lower: Nothing; upper: Inv<out Out<In<In<Inv<in In<Int>>>>>>; substitution: Inv<Out<In<In<Inv<in In<out Any?>>>>>>
+
+Inv<In<Inv<Inv<in Inv<out Inv<out T>>>>>>
+  in Int. lower: Nothing; upper: Inv<out In<Nothing>>; substitution: Inv<In<Inv<Inv<in Inv<out Inv<out Int>>>>>>
+  out Int. lower: Nothing; upper: Inv<out In<Nothing>>; substitution: Inv<In<Inv<Inv<in Inv<out Inv<out Int>>>>>>
+
+In<Inv<out Inv<in Inv<Inv<in Inv<out T>>>>>>
+  in Int. lower: In<Inv<out Inv<out Any?>>>; upper: In<Inv<out Inv<in Inv<out Inv<in Inv<out Int>>>>>>; substitution: In<Inv<out Inv<in Inv<Inv<in Inv<out Int>>>>>>
+  out Int. lower: In<Inv<out Inv<out Any?>>>; upper: In<Inv<out Inv<in Inv<out Inv<in Inv<Nothing>>>>>>; substitution: In<Inv<out Inv<in Inv<Inv<in Inv<out Int>>>>>>
+
+In<Inv<Inv<out Inv<out In<In<T>>>>>>
+  in Int. lower: In<Inv<out Inv<out Inv<out In<In<Any?>>>>>>; upper: In<Nothing>; substitution: In<Inv<Inv<out Inv<out In<In<Int>>>>>>
+  out Int. lower: In<Inv<out Inv<out Inv<out In<In<Int>>>>>>; upper: In<Nothing>; substitution: In<Inv<Inv<out Inv<out In<In<out Any?>>>>>>
+
+Out<In<Inv<Out<Inv<Out<T>>>>>>
+  in Int. lower: Out<In<Inv<out Out<Inv<out Out<Any?>>>>>>; upper: Out<In<Nothing>>; substitution: Out<In<Inv<Out<Inv<Out<Any?>>>>>>
+  out Int. lower: Out<In<Inv<out Out<Inv<out Out<Int>>>>>>; upper: Out<In<Nothing>>; substitution: Out<In<Inv<Out<Inv<Out<Int>>>>>>
+
+Inv<out Inv<Inv<in Out<Inv<out Inv<in T>>>>>>
+  in Int. lower: Inv<Nothing>; upper: Inv<out Inv<out Inv<in Out<Inv<out Inv<Any?>>>>>>; substitution: Inv<out Inv<Inv<in Out<Inv<out Inv<in Int>>>>>>
+  out Int. lower: Inv<Nothing>; upper: Inv<out Inv<out Inv<in Out<Inv<out Inv<in Int>>>>>>; substitution: Inv<out Inv<Inv<in Out<Inv<out Inv<in Int>>>>>>
+
+Out<Inv<in Inv<Out<Inv<Out<T>>>>>>
+  in Int. lower: Out<Inv<in Inv<out Out<Inv<out Out<Any?>>>>>>; upper: Out<Inv<out Any?>>; substitution: Out<Inv<in Inv<Out<Inv<Out<Any?>>>>>>
+  out Int. lower: Out<Inv<in Inv<out Out<Inv<out Out<Int>>>>>>; upper: Out<Inv<out Any?>>; substitution: Out<Inv<in Inv<Out<Inv<Out<Int>>>>>>
+
+Inv<Inv<in Inv<in In<In<Out<T>>>>>>
+  in Int. lower: Nothing; upper: Inv<out Inv<in Inv<in In<In<Out<Any?>>>>>>; substitution: Inv<Inv<in Inv<in In<In<Out<Any?>>>>>>
+  out Int. lower: Nothing; upper: Inv<out Inv<in Inv<in In<In<Out<Int>>>>>>; substitution: Inv<Inv<in Inv<in In<In<Out<Int>>>>>>

compiler/testData/capturedTypeApproximation/twoVariables.txt

@@ -0,0 +1,179 @@
+In<Fun<T, R>>
+  T = in Int. R = out String. lower: In<Fun<Int, String>>; upper: In<Fun<Any?, Nothing>>; substitution: In<Fun<Int, String>>
+
+Out<Fun<T, R>>
+  T = in Int. R = out String. lower: Out<Fun<Any?, Nothing>>; upper: Out<Fun<Int, String>>; substitution: Out<Fun<Int, String>>
+
+Inv<Fun<T, R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv<out Fun<Int, String>>; substitution: Inv<Fun<Int, String>>
+
+Inv<in Fun<T, R>>
+  T = in Int. R = out String. lower: Inv<in Fun<Int, String>>; upper: Inv<in Fun<Any?, Nothing>>; substitution: Inv<in Fun<Int, String>>
+
+Inv<out Fun<T, R>>
+  T = in Int. R = out String. lower: Inv<out Fun<Any?, Nothing>>; upper: Inv<out Fun<Int, String>>; substitution: Inv<out Fun<Int, String>>
+
+Fun<In<T>, In<R>>
+  T = in Int. R = out String. lower: Fun<In<Int>, In<String>>; upper: Fun<In<Any?>, In<Nothing>>; substitution: Fun<In<Int>, In<out Any?>>
+
+Fun<In<T>, Out<R>>
+  T = in Int. R = out String. lower: Fun<In<Int>, Out<Nothing>>; upper: Fun<In<Any?>, Out<String>>; substitution: Fun<In<Int>, Out<String>>
+
+Fun<In<T>, Inv<R>>
+  T = in Int. R = out String. lower: Fun<In<Int>, Nothing>; upper: Fun<In<Any?>, Inv<out String>>; substitution: Fun<In<Int>, Inv<out String>>
+
+Fun<In<T>, Inv<in R>>
+  T = in Int. R = out String. lower: Fun<In<Int>, Inv<in String>>; upper: Fun<In<Any?>, Inv<out Any?>>; substitution: Fun<In<Int>, Inv<in String>>
+
+Fun<In<T>, Inv<out R>>
+  T = in Int. R = out String. lower: Fun<In<Int>, Inv<Nothing>>; upper: Fun<In<Any?>, Inv<out String>>; substitution: Fun<In<Int>, Inv<out String>>
+
+Fun<Out<T>, In<R>>
+  T = in Int. R = out String. lower: Fun<Out<Any?>, In<String>>; upper: Fun<Out<Int>, In<Nothing>>; substitution: Fun<Out<Any?>, In<out Any?>>
+
+Fun<Out<T>, Out<R>>
+  T = in Int. R = out String. lower: Fun<Out<Any?>, Out<Nothing>>; upper: Fun<Out<Int>, Out<String>>; substitution: Fun<Out<Any?>, Out<String>>
+
+Fun<Out<T>, Inv<R>>
+  T = in Int. R = out String. lower: Fun<Out<Any?>, Nothing>; upper: Fun<Out<Int>, Inv<out String>>; substitution: Fun<Out<Any?>, Inv<out String>>
+
+Fun<Out<T>, Inv<in R>>
+  T = in Int. R = out String. lower: Fun<Out<Any?>, Inv<in String>>; upper: Fun<Out<Int>, Inv<out Any?>>; substitution: Fun<Out<Any?>, Inv<in String>>
+
+Fun<Out<T>, Inv<out R>>
+  T = in Int. R = out String. lower: Fun<Out<Any?>, Inv<Nothing>>; upper: Fun<Out<Int>, Inv<out String>>; substitution: Fun<Out<Any?>, Inv<out String>>
+
+Fun<Inv<T>, In<R>>
+  T = in Int. R = out String. lower: Fun<Inv<in Int>, In<String>>; upper: Fun<Nothing, In<Nothing>>; substitution: Fun<Inv<in Int>, In<out Any?>>
+
+Fun<Inv<T>, Out<R>>
+  T = in Int. R = out String. lower: Fun<Inv<in Int>, Out<Nothing>>; upper: Fun<Nothing, Out<String>>; substitution: Fun<Inv<in Int>, Out<String>>
+
+Fun<Inv<T>, Inv<R>>
+  T = in Int. R = out String. lower: Fun<Inv<in Int>, Nothing>; upper: Fun<Nothing, Inv<out String>>; substitution: Fun<Inv<in Int>, Inv<out String>>
+
+Fun<Inv<T>, Inv<in R>>
+  T = in Int. R = out String. lower: Fun<Inv<in Int>, Inv<in String>>; upper: Fun<Nothing, Inv<out Any?>>; substitution: Fun<Inv<in Int>, Inv<in String>>
+
+Fun<Inv<T>, Inv<out R>>
+  T = in Int. R = out String. lower: Fun<Inv<in Int>, Inv<Nothing>>; upper: Fun<Nothing, Inv<out String>>; substitution: Fun<Inv<in Int>, Inv<out String>>
+
+Fun<Inv<in T>, In<R>>
+  T = in Int. R = out String. lower: Fun<Inv<in Int>, In<String>>; upper: Fun<Inv<Any?>, In<Nothing>>; substitution: Fun<Inv<in Int>, In<out Any?>>
+
+Fun<Inv<in T>, Out<R>>
+  T = in Int. R = out String. lower: Fun<Inv<in Int>, Out<Nothing>>; upper: Fun<Inv<Any?>, Out<String>>; substitution: Fun<Inv<in Int>, Out<String>>
+
+Fun<Inv<in T>, Inv<R>>
+  T = in Int. R = out String. lower: Fun<Inv<in Int>, Nothing>; upper: Fun<Inv<Any?>, Inv<out String>>; substitution: Fun<Inv<in Int>, Inv<out String>>
+
+Fun<Inv<in T>, Inv<in R>>
+  T = in Int. R = out String. lower: Fun<Inv<in Int>, Inv<in String>>; upper: Fun<Inv<Any?>, Inv<out Any?>>; substitution: Fun<Inv<in Int>, Inv<in String>>
+
+Fun<Inv<in T>, Inv<out R>>
+  T = in Int. R = out String. lower: Fun<Inv<in Int>, Inv<Nothing>>; upper: Fun<Inv<Any?>, Inv<out String>>; substitution: Fun<Inv<in Int>, Inv<out String>>
+
+Fun<Inv<out T>, In<R>>
+  T = in Int. R = out String. lower: Fun<Inv<out Any?>, In<String>>; upper: Fun<Inv<out Int>, In<Nothing>>; substitution: Fun<Inv<out Int>, In<out Any?>>
+
+Fun<Inv<out T>, Out<R>>
+  T = in Int. R = out String. lower: Fun<Inv<out Any?>, Out<Nothing>>; upper: Fun<Inv<out Int>, Out<String>>; substitution: Fun<Inv<out Int>, Out<String>>
+
+Fun<Inv<out T>, Inv<R>>
+  T = in Int. R = out String. lower: Fun<Inv<out Any?>, Nothing>; upper: Fun<Inv<out Int>, Inv<out String>>; substitution: Fun<Inv<out Int>, Inv<out String>>
+
+Fun<Inv<out T>, Inv<in R>>
+  T = in Int. R = out String. lower: Fun<Inv<out Any?>, Inv<in String>>; upper: Fun<Inv<out Int>, Inv<out Any?>>; substitution: Fun<Inv<out Int>, Inv<in String>>
+
+Fun<Inv<out T>, Inv<out R>>
+  T = in Int. R = out String. lower: Fun<Inv<out Any?>, Inv<Nothing>>; upper: Fun<Inv<out Int>, Inv<out String>>; substitution: Fun<Inv<out Int>, Inv<out String>>
+
+In<Inv2<T, R>>
+  T = in Int. R = out String. lower: In<Inv2<in Int, out String>>; upper: In<Nothing>; substitution: In<Inv2<in Int, out String>>
+
+Out<Inv2<T, R>>
+  T = in Int. R = out String. lower: Out<Nothing>; upper: Out<Inv2<in Int, out String>>; substitution: Out<Inv2<in Int, out String>>
+
+Inv<Inv2<T, R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv<out Inv2<in Int, out String>>; substitution: Inv<Inv2<in Int, out String>>
+
+Inv<in Inv2<T, R>>
+  T = in Int. R = out String. lower: Inv<in Inv2<in Int, out String>>; upper: Inv<out Any?>; substitution: Inv<in Inv2<in Int, out String>>
+
+Inv<out Inv2<T, R>>
+  T = in Int. R = out String. lower: Inv<Nothing>; upper: Inv<out Inv2<in Int, out String>>; substitution: Inv<out Inv2<in Int, out String>>
+
+Inv2<In<T>, In<R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out In<Int>, out In<Nothing>>; substitution: Inv2<In<Int>, In<out Any?>>
+
+Inv2<In<T>, Out<R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out In<Int>, out Out<String>>; substitution: Inv2<In<Int>, Out<String>>
+
+Inv2<In<T>, Inv<R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out In<Int>, out Inv<out String>>; substitution: Inv2<In<Int>, Inv<out String>>
+
+Inv2<In<T>, Inv<in R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out In<Int>, out Inv<out Any?>>; substitution: Inv2<In<Int>, Inv<in String>>
+
+Inv2<In<T>, Inv<out R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out In<Int>, out Inv<out String>>; substitution: Inv2<In<Int>, Inv<out String>>
+
+Inv2<Out<T>, In<R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out Out<Any?>, out In<Nothing>>; substitution: Inv2<Out<Any?>, In<out Any?>>
+
+Inv2<Out<T>, Out<R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out Out<Any?>, out Out<String>>; substitution: Inv2<Out<Any?>, Out<String>>
+
+Inv2<Out<T>, Inv<R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out Out<Any?>, out Inv<out String>>; substitution: Inv2<Out<Any?>, Inv<out String>>
+
+Inv2<Out<T>, Inv<in R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out Out<Any?>, out Inv<out Any?>>; substitution: Inv2<Out<Any?>, Inv<in String>>
+
+Inv2<Out<T>, Inv<out R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out Out<Any?>, out Inv<out String>>; substitution: Inv2<Out<Any?>, Inv<out String>>
+
+Inv2<Inv<T>, In<R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out Inv<in Int>, out In<Nothing>>; substitution: Inv2<Inv<in Int>, In<out Any?>>
+
+Inv2<Inv<T>, Out<R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out Inv<in Int>, out Out<String>>; substitution: Inv2<Inv<in Int>, Out<String>>
+
+Inv2<Inv<T>, Inv<R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out Inv<in Int>, out Inv<out String>>; substitution: Inv2<Inv<in Int>, Inv<out String>>
+
+Inv2<Inv<T>, Inv<in R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out Inv<in Int>, out Inv<out Any?>>; substitution: Inv2<Inv<in Int>, Inv<in String>>
+
+Inv2<Inv<T>, Inv<out R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out Inv<in Int>, out Inv<out String>>; substitution: Inv2<Inv<in Int>, Inv<out String>>
+
+Inv2<Inv<in T>, In<R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out Inv<in Int>, out In<Nothing>>; substitution: Inv2<Inv<in Int>, In<out Any?>>
+
+Inv2<Inv<in T>, Out<R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out Inv<in Int>, out Out<String>>; substitution: Inv2<Inv<in Int>, Out<String>>
+
+Inv2<Inv<in T>, Inv<R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out Inv<in Int>, out Inv<out String>>; substitution: Inv2<Inv<in Int>, Inv<out String>>
+
+Inv2<Inv<in T>, Inv<in R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out Inv<in Int>, out Inv<out Any?>>; substitution: Inv2<Inv<in Int>, Inv<in String>>
+
+Inv2<Inv<in T>, Inv<out R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out Inv<in Int>, out Inv<out String>>; substitution: Inv2<Inv<in Int>, Inv<out String>>
+
+Inv2<Inv<out T>, In<R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out Inv<out Any?>, out In<Nothing>>; substitution: Inv2<Inv<out Int>, In<out Any?>>
+
+Inv2<Inv<out T>, Out<R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out Inv<out Any?>, out Out<String>>; substitution: Inv2<Inv<out Int>, Out<String>>
+
+Inv2<Inv<out T>, Inv<R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out Inv<out Any?>, out Inv<out String>>; substitution: Inv2<Inv<out Int>, Inv<out String>>
+
+Inv2<Inv<out T>, Inv<in R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out Inv<out Any?>, out Inv<out Any?>>; substitution: Inv2<Inv<out Int>, Inv<in String>>
+
+Inv2<Inv<out T>, Inv<out R>>
+  T = in Int. R = out String. lower: Nothing; upper: Inv2<out Inv<out Any?>, out Inv<out String>>; substitution: Inv2<Inv<out Int>, Inv<out String>>

compiler/testData/capturedTypeApproximation/useSiteInNullableT.txt

@@ -0,0 +1,236 @@
+In<in T?>
+  in Int. lower: In<Any?>; upper: In<Int?>; substitution: In<Int?>
+  out Int. lower: In<Int?>; upper: In<Nothing?>; substitution: In<out Any?>
+
+Out<in T?>
+  compiler error
+
+Inv<in T?>
+  in Int. lower: Inv<Any?>; upper: Inv<in Int?>; substitution: Inv<in Int?>
+  out Int. lower: Inv<in Int?>; upper: Inv<in Nothing?>; substitution: Inv<in Int?>
+
+Inv<in in T?>
+  compiler error
+
+Inv<out in T?>
+  compiler error
+
+In<In<in T?>>
+  in Int. lower: In<In<Int?>>; upper: In<In<Any?>>; substitution: In<In<Int?>>
+  out Int. lower: In<In<Nothing?>>; upper: In<In<Int?>>; substitution: In<In<out Any?>>
+
+In<Out<in T?>>
+  compiler error
+
+In<Inv<in T?>>
+  in Int. lower: In<Inv<in Int?>>; upper: In<Inv<Any?>>; substitution: In<Inv<in Int?>>
+  out Int. lower: In<Inv<in Nothing?>>; upper: In<Inv<in Int?>>; substitution: In<Inv<in Int?>>
+
+In<Inv<in in T?>>
+  compiler error
+
+In<Inv<out in T?>>
+  compiler error
+
+Out<In<in T?>>
+  in Int. lower: Out<In<Any?>>; upper: Out<In<Int?>>; substitution: Out<In<Int?>>
+  out Int. lower: Out<In<Int?>>; upper: Out<In<Nothing?>>; substitution: Out<In<out Any?>>
+
+Out<Out<in T?>>
+  compiler error
+
+Out<Inv<in T?>>
+  in Int. lower: Out<Inv<Any?>>; upper: Out<Inv<in Int?>>; substitution: Out<Inv<in Int?>>
+  out Int. lower: Out<Inv<in Int?>>; upper: Out<Inv<in Nothing?>>; substitution: Out<Inv<in Int?>>
+
+Out<Inv<in in T?>>
+  compiler error
+
+Out<Inv<out in T?>>
+  compiler error
+
+Inv<In<in T?>>
+  in Int. lower: Nothing; upper: Inv<out In<Int?>>; substitution: Inv<In<Int?>>
+  out Int. lower: Nothing; upper: Inv<out In<Nothing?>>; substitution: Inv<In<out Any?>>
+
+Inv<Out<in T?>>
+  compiler error
+
+Inv<Inv<in T?>>
+  in Int. lower: Nothing; upper: Inv<out Inv<in Int?>>; substitution: Inv<Inv<in Int?>>
+  out Int. lower: Nothing; upper: Inv<out Inv<in Nothing?>>; substitution: Inv<Inv<in Int?>>
+
+Inv<Inv<in in T?>>
+  compiler error
+
+Inv<Inv<out in T?>>
+  compiler error
+
+Inv<in In<in T?>>
+  in Int. lower: Inv<in In<Int?>>; upper: Inv<in In<Any?>>; substitution: Inv<in In<Int?>>
+  out Int. lower: Inv<in In<Nothing?>>; upper: Inv<in In<Int?>>; substitution: Inv<in In<out Any?>>
+
+Inv<in Out<in T?>>
+  compiler error
+
+Inv<in Inv<in T?>>
+  in Int. lower: Inv<in Inv<in Int?>>; upper: Inv<in Inv<Any?>>; substitution: Inv<in Inv<in Int?>>
+  out Int. lower: Inv<in Inv<in Nothing?>>; upper: Inv<in Inv<in Int?>>; substitution: Inv<in Inv<in Int?>>
+
+Inv<in Inv<in in T?>>
+  compiler error
+
+Inv<in Inv<out in T?>>
+  compiler error
+
+Inv<out In<in T?>>
+  in Int. lower: Inv<out In<Any?>>; upper: Inv<out In<Int?>>; substitution: Inv<out In<Int?>>
+  out Int. lower: Inv<out In<Int?>>; upper: Inv<out In<Nothing?>>; substitution: Inv<out In<out Any?>>
+
+Inv<out Out<in T?>>
+  compiler error
+
+Inv<out Inv<in T?>>
+  in Int. lower: Inv<out Inv<Any?>>; upper: Inv<out Inv<in Int?>>; substitution: Inv<out Inv<in Int?>>
+  out Int. lower: Inv<out Inv<in Int?>>; upper: Inv<out Inv<in Nothing?>>; substitution: Inv<out Inv<in Int?>>
+
+Inv<out Inv<in in T?>>
+  compiler error
+
+Inv<out Inv<out in T?>>
+  compiler error
+
+In<Inv<Out<in T?>>>
+  compiler error
+
+Out<Out<Out<in T?>>>
+  compiler error
+
+Inv<Inv<in In<in T?>>>
+  in Int. lower: Nothing; upper: Inv<out Inv<in In<Any?>>>; substitution: Inv<Inv<in In<Int?>>>
+  out Int. lower: Nothing; upper: Inv<out Inv<in In<Int?>>>; substitution: Inv<Inv<in In<out Any?>>>
+
+Inv<out Inv<Out<in T?>>>
+  compiler error
+
+Inv<in Inv<Inv<in T?>>>
+  in Int. lower: Inv<in Inv<out Inv<in Int?>>>; upper: Inv<out Any?>; substitution: Inv<in Inv<Inv<in Int?>>>
+  out Int. lower: Inv<in Inv<out Inv<in Nothing?>>>; upper: Inv<out Any?>; substitution: Inv<in Inv<Inv<in Int?>>>
+
+Out<Inv<In<in T?>>>
+  in Int. lower: Out<Nothing>; upper: Out<Inv<out In<Int?>>>; substitution: Out<Inv<In<Int?>>>
+  out Int. lower: Out<Nothing>; upper: Out<Inv<out In<Nothing?>>>; substitution: Out<Inv<In<out Any?>>>
+
+Inv<out Out<Out<in T?>>>
+  compiler error
+
+Out<In<Inv<in T?>>>
+  in Int. lower: Out<In<Inv<in Int?>>>; upper: Out<In<Inv<Any?>>>; substitution: Out<In<Inv<in Int?>>>
+  out Int. lower: Out<In<Inv<in Nothing?>>>; upper: Out<In<Inv<in Int?>>>; substitution: Out<In<Inv<in Int?>>>
+
+Inv<out In<Out<in T?>>>
+  compiler error
+
+In<Out<Inv<in T?>>>
+  in Int. lower: In<Out<Inv<in Int?>>>; upper: In<Out<Inv<Any?>>>; substitution: In<Out<Inv<in Int?>>>
+  out Int. lower: In<Out<Inv<in Nothing?>>>; upper: In<Out<Inv<in Int?>>>; substitution: In<Out<Inv<in Int?>>>
+
+Inv<out Inv<Inv<out Inv<in in T?>>>>
+  compiler error
+
+Inv<in Out<In<Inv<in in T?>>>>
+  compiler error
+
+Inv<in In<Inv<out Inv<in in T?>>>>
+  compiler error
+
+Inv<In<In<Inv<in in T?>>>>
+  compiler error
+
+Inv<out Inv<out Inv<out Inv<in T?>>>>
+  in Int. lower: Inv<out Inv<out Inv<out Inv<Any?>>>>; upper: Inv<out Inv<out Inv<out Inv<in Int?>>>>; substitution: Inv<out Inv<out Inv<out Inv<in Int?>>>>
+  out Int. lower: Inv<out Inv<out Inv<out Inv<in Int?>>>>; upper: Inv<out Inv<out Inv<out Inv<in Nothing?>>>>; substitution: Inv<out Inv<out Inv<out Inv<in Int?>>>>
+
+Inv<out Out<Inv<out Inv<in in T?>>>>
+  compiler error
+
+Out<Inv<out Inv<out In<in T?>>>>
+  in Int. lower: Out<Inv<out Inv<out In<Any?>>>>; upper: Out<Inv<out Inv<out In<Int?>>>>; substitution: Out<Inv<out Inv<out In<Int?>>>>
+  out Int. lower: Out<Inv<out Inv<out In<Int?>>>>; upper: Out<Inv<out Inv<out In<Nothing?>>>>; substitution: Out<Inv<out Inv<out In<out Any?>>>>
+
+In<Inv<in In<Inv<in in T?>>>>
+  compiler error
+
+Out<Inv<in In<Inv<in T?>>>>
+  in Int. lower: Out<Inv<in In<Inv<Any?>>>>; upper: Out<Inv<in In<Inv<in Int?>>>>; substitution: Out<Inv<in In<Inv<in Int?>>>>
+  out Int. lower: Out<Inv<in In<Inv<in Int?>>>>; upper: Out<Inv<in In<Inv<in Nothing?>>>>; substitution: Out<Inv<in In<Inv<in Int?>>>>
+
+Out<Inv<in Inv<in Inv<in T?>>>>
+  in Int. lower: Out<Inv<in Inv<in Inv<Any?>>>>; upper: Out<Inv<in Inv<in Inv<in Int?>>>>; substitution: Out<Inv<in Inv<in Inv<in Int?>>>>
+  out Int. lower: Out<Inv<in Inv<in Inv<in Int?>>>>; upper: Out<Inv<in Inv<in Inv<in Nothing?>>>>; substitution: Out<Inv<in Inv<in Inv<in Int?>>>>
+
+In<In<Inv<In<In<in T?>>>>>
+  in Int. lower: In<In<Nothing>>; upper: In<In<Inv<out In<In<Any?>>>>>; substitution: In<In<Inv<In<In<Int?>>>>>
+  out Int. lower: In<In<Nothing>>; upper: In<In<Inv<out In<In<Int?>>>>>; substitution: In<In<Inv<In<In<out Any?>>>>>
+
+Inv<Inv<Inv<Out<Inv<in in T?>>>>>
+  compiler error
+
+Out<Inv<Out<Out<Inv<out in T?>>>>>
+  compiler error
+
+Inv<In<Inv<in In<Inv<out in T?>>>>>
+  compiler error
+
+Inv<in Inv<out In<Out<Inv<out in T?>>>>>
+  compiler error
+
+Inv<out Out<Inv<in Inv<in Inv<in in T?>>>>>
+  compiler error
+
+Out<Out<Inv<Out<Inv<out in T?>>>>>
+  compiler error
+
+In<Inv<In<In<Inv<out in T?>>>>>
+  compiler error
+
+Inv<out Inv<in Inv<Inv<out Inv<out in T?>>>>>
+  compiler error
+
+In<Inv<in In<In<Inv<out in T?>>>>>
+  compiler error
+
+In<Inv<Out<In<Inv<Inv<in T?>>>>>>
+  in Int. lower: In<Inv<out Out<In<Nothing>>>>; upper: In<Nothing>; substitution: In<Inv<Out<In<Inv<Inv<in Int?>>>>>>
+  out Int. lower: In<Inv<out Out<In<Nothing>>>>; upper: In<Nothing>; substitution: In<Inv<Out<In<Inv<Inv<in Int?>>>>>>
+
+Out<Inv<Inv<out Inv<Inv<in In<in T?>>>>>>
+  in Int. lower: Out<Nothing>; upper: Out<Inv<out Inv<out Inv<out Inv<in In<Any?>>>>>>; substitution: Out<Inv<Inv<out Inv<Inv<in In<Int?>>>>>>
+  out Int. lower: Out<Nothing>; upper: Out<Inv<out Inv<out Inv<out Inv<in In<Int?>>>>>>; substitution: Out<Inv<Inv<out Inv<Inv<in In<out Any?>>>>>>
+
+Inv<Out<In<In<Inv<in In<in T?>>>>>>
+  in Int. lower: Nothing; upper: Inv<out Out<In<In<Inv<in In<Any?>>>>>>; substitution: Inv<Out<In<In<Inv<in In<Int?>>>>>>
+  out Int. lower: Nothing; upper: Inv<out Out<In<In<Inv<in In<Int?>>>>>>; substitution: Inv<Out<In<In<Inv<in In<out Any?>>>>>>
+
+Inv<In<Inv<Inv<in Inv<out Inv<out in T?>>>>>>
+  compiler error
+
+In<Inv<out Inv<in Inv<Inv<in Inv<out in T?>>>>>>
+  compiler error
+
+In<Inv<Inv<out Inv<out In<In<in T?>>>>>>
+  in Int. lower: In<Inv<out Inv<out Inv<out In<In<Any?>>>>>>; upper: In<Nothing>; substitution: In<Inv<Inv<out Inv<out In<In<Int?>>>>>>
+  out Int. lower: In<Inv<out Inv<out Inv<out In<In<Int?>>>>>>; upper: In<Nothing>; substitution: In<Inv<Inv<out Inv<out In<In<out Any?>>>>>>
+
+Out<In<Inv<Out<Inv<Out<in T?>>>>>>
+  compiler error
+
+Inv<out Inv<Inv<in Out<Inv<out Inv<in in T?>>>>>>
+  compiler error
+
+Out<Inv<in Inv<Out<Inv<Out<in T?>>>>>>
+  compiler error
+
+Inv<Inv<in Inv<in In<In<Out<in T?>>>>>>
+  compiler error
+

compiler/testData/capturedTypeApproximation/useSiteInT.txt

@@ -0,0 +1,236 @@
+In<in T>
+  in Int. lower: In<Any?>; upper: In<Int>; substitution: In<Int>
+  out Int. lower: In<Int>; upper: In<Nothing>; substitution: In<out Any?>
+
+Out<in T>
+  compiler error
+
+Inv<in T>
+  in Int. lower: Inv<Any?>; upper: Inv<in Int>; substitution: Inv<in Int>
+  out Int. lower: Inv<in Int>; upper: Inv<out Any?>; substitution: Inv<in Int>
+
+Inv<in in T>
+  compiler error
+
+Inv<out in T>
+  compiler error
+
+In<In<in T>>
+  in Int. lower: In<In<Int>>; upper: In<In<Any?>>; substitution: In<In<Int>>
+  out Int. lower: In<In<Nothing>>; upper: In<In<Int>>; substitution: In<In<out Any?>>
+
+In<Out<in T>>
+  compiler error
+
+In<Inv<in T>>
+  in Int. lower: In<Inv<in Int>>; upper: In<Inv<Any?>>; substitution: In<Inv<in Int>>
+  out Int. lower: In<Inv<out Any?>>; upper: In<Inv<in Int>>; substitution: In<Inv<in Int>>
+
+In<Inv<in in T>>
+  compiler error
+
+In<Inv<out in T>>
+  compiler error
+
+Out<In<in T>>
+  in Int. lower: Out<In<Any?>>; upper: Out<In<Int>>; substitution: Out<In<Int>>
+  out Int. lower: Out<In<Int>>; upper: Out<In<Nothing>>; substitution: Out<In<out Any?>>
+
+Out<Out<in T>>
+  compiler error
+
+Out<Inv<in T>>
+  in Int. lower: Out<Inv<Any?>>; upper: Out<Inv<in Int>>; substitution: Out<Inv<in Int>>
+  out Int. lower: Out<Inv<in Int>>; upper: Out<Inv<out Any?>>; substitution: Out<Inv<in Int>>
+
+Out<Inv<in in T>>
+  compiler error
+
+Out<Inv<out in T>>
+  compiler error
+
+Inv<In<in T>>
+  in Int. lower: Nothing; upper: Inv<out In<Int>>; substitution: Inv<In<Int>>
+  out Int. lower: Nothing; upper: Inv<out In<Nothing>>; substitution: Inv<In<out Any?>>
+
+Inv<Out<in T>>
+  compiler error
+
+Inv<Inv<in T>>
+  in Int. lower: Nothing; upper: Inv<out Inv<in Int>>; substitution: Inv<Inv<in Int>>
+  out Int. lower: Nothing; upper: Inv<out Inv<out Any?>>; substitution: Inv<Inv<in Int>>
+
+Inv<Inv<in in T>>
+  compiler error
+
+Inv<Inv<out in T>>
+  compiler error
+
+Inv<in In<in T>>
+  in Int. lower: Inv<in In<Int>>; upper: Inv<in In<Any?>>; substitution: Inv<in In<Int>>
+  out Int. lower: Inv<in In<Nothing>>; upper: Inv<in In<Int>>; substitution: Inv<in In<out Any?>>
+
+Inv<in Out<in T>>
+  compiler error
+
+Inv<in Inv<in T>>
+  in Int. lower: Inv<in Inv<in Int>>; upper: Inv<in Inv<Any?>>; substitution: Inv<in Inv<in Int>>
+  out Int. lower: Inv<in Inv<out Any?>>; upper: Inv<in Inv<in Int>>; substitution: Inv<in Inv<in Int>>
+
+Inv<in Inv<in in T>>
+  compiler error
+
+Inv<in Inv<out in T>>
+  compiler error
+
+Inv<out In<in T>>
+  in Int. lower: Inv<out In<Any?>>; upper: Inv<out In<Int>>; substitution: Inv<out In<Int>>
+  out Int. lower: Inv<out In<Int>>; upper: Inv<out In<Nothing>>; substitution: Inv<out In<out Any?>>
+
+Inv<out Out<in T>>
+  compiler error
+
+Inv<out Inv<in T>>
+  in Int. lower: Inv<out Inv<Any?>>; upper: Inv<out Inv<in Int>>; substitution: Inv<out Inv<in Int>>
+  out Int. lower: Inv<out Inv<in Int>>; upper: Inv<out Inv<out Any?>>; substitution: Inv<out Inv<in Int>>
+
+Inv<out Inv<in in T>>
+  compiler error
+
+Inv<out Inv<out in T>>
+  compiler error
+
+In<Inv<Out<in T>>>
+  compiler error
+
+Out<Out<Out<in T>>>
+  compiler error
+
+Inv<Inv<in In<in T>>>
+  in Int. lower: Nothing; upper: Inv<out Inv<in In<Any?>>>; substitution: Inv<Inv<in In<Int>>>
+  out Int. lower: Nothing; upper: Inv<out Inv<in In<Int>>>; substitution: Inv<Inv<in In<out Any?>>>
+
+Inv<out Inv<Out<in T>>>
+  compiler error
+
+Inv<in Inv<Inv<in T>>>
+  in Int. lower: Inv<in Inv<out Inv<in Int>>>; upper: Inv<out Any?>; substitution: Inv<in Inv<Inv<in Int>>>
+  out Int. lower: Inv<in Inv<out Inv<out Any?>>>; upper: Inv<out Any?>; substitution: Inv<in Inv<Inv<in Int>>>
+
+Out<Inv<In<in T>>>
+  in Int. lower: Out<Nothing>; upper: Out<Inv<out In<Int>>>; substitution: Out<Inv<In<Int>>>
+  out Int. lower: Out<Nothing>; upper: Out<Inv<out In<Nothing>>>; substitution: Out<Inv<In<out Any?>>>
+
+Inv<out Out<Out<in T>>>
+  compiler error
+
+Out<In<Inv<in T>>>
+  in Int. lower: Out<In<Inv<in Int>>>; upper: Out<In<Inv<Any?>>>; substitution: Out<In<Inv<in Int>>>
+  out Int. lower: Out<In<Inv<out Any?>>>; upper: Out<In<Inv<in Int>>>; substitution: Out<In<Inv<in Int>>>
+
+Inv<out In<Out<in T>>>
+  compiler error
+
+In<Out<Inv<in T>>>
+  in Int. lower: In<Out<Inv<in Int>>>; upper: In<Out<Inv<Any?>>>; substitution: In<Out<Inv<in Int>>>
+  out Int. lower: In<Out<Inv<out Any?>>>; upper: In<Out<Inv<in Int>>>; substitution: In<Out<Inv<in Int>>>
+
+Inv<out Inv<Inv<out Inv<in in T>>>>
+  compiler error
+
+Inv<in Out<In<Inv<in in T>>>>
+  compiler error
+
+Inv<in In<Inv<out Inv<in in T>>>>
+  compiler error
+
+Inv<In<In<Inv<in in T>>>>
+  compiler error
+
+Inv<out Inv<out Inv<out Inv<in T>>>>
+  in Int. lower: Inv<out Inv<out Inv<out Inv<Any?>>>>; upper: Inv<out Inv<out Inv<out Inv<in Int>>>>; substitution: Inv<out Inv<out Inv<out Inv<in Int>>>>
+  out Int. lower: Inv<out Inv<out Inv<out Inv<in Int>>>>; upper: Inv<out Inv<out Inv<out Inv<out Any?>>>>; substitution: Inv<out Inv<out Inv<out Inv<in Int>>>>
+
+Inv<out Out<Inv<out Inv<in in T>>>>
+  compiler error
+
+Out<Inv<out Inv<out In<in T>>>>
+  in Int. lower: Out<Inv<out Inv<out In<Any?>>>>; upper: Out<Inv<out Inv<out In<Int>>>>; substitution: Out<Inv<out Inv<out In<Int>>>>
+  out Int. lower: Out<Inv<out Inv<out In<Int>>>>; upper: Out<Inv<out Inv<out In<Nothing>>>>; substitution: Out<Inv<out Inv<out In<out Any?>>>>
+
+In<Inv<in In<Inv<in in T>>>>
+  compiler error
+
+Out<Inv<in In<Inv<in T>>>>
+  in Int. lower: Out<Inv<in In<Inv<Any?>>>>; upper: Out<Inv<in In<Inv<in Int>>>>; substitution: Out<Inv<in In<Inv<in Int>>>>
+  out Int. lower: Out<Inv<in In<Inv<in Int>>>>; upper: Out<Inv<in In<Inv<out Any?>>>>; substitution: Out<Inv<in In<Inv<in Int>>>>
+
+Out<Inv<in Inv<in Inv<in T>>>>
+  in Int. lower: Out<Inv<in Inv<in Inv<Any?>>>>; upper: Out<Inv<in Inv<in Inv<in Int>>>>; substitution: Out<Inv<in Inv<in Inv<in Int>>>>
+  out Int. lower: Out<Inv<in Inv<in Inv<in Int>>>>; upper: Out<Inv<in Inv<in Inv<out Any?>>>>; substitution: Out<Inv<in Inv<in Inv<in Int>>>>
+
+In<In<Inv<In<In<in T>>>>>
+  in Int. lower: In<In<Nothing>>; upper: In<In<Inv<out In<In<Any?>>>>>; substitution: In<In<Inv<In<In<Int>>>>>
+  out Int. lower: In<In<Nothing>>; upper: In<In<Inv<out In<In<Int>>>>>; substitution: In<In<Inv<In<In<out Any?>>>>>
+
+Inv<Inv<Inv<Out<Inv<in in T>>>>>
+  compiler error
+
+Out<Inv<Out<Out<Inv<out in T>>>>>
+  compiler error
+
+Inv<In<Inv<in In<Inv<out in T>>>>>
+  compiler error
+
+Inv<in Inv<out In<Out<Inv<out in T>>>>>
+  compiler error
+
+Inv<out Out<Inv<in Inv<in Inv<in in T>>>>>
+  compiler error
+
+Out<Out<Inv<Out<Inv<out in T>>>>>
+  compiler error
+
+In<Inv<In<In<Inv<out in T>>>>>
+  compiler error
+
+Inv<out Inv<in Inv<Inv<out Inv<out in T>>>>>
+  compiler error
+
+In<Inv<in In<In<Inv<out in T>>>>>
+  compiler error
+
+In<Inv<Out<In<Inv<Inv<in T>>>>>>
+  in Int. lower: In<Inv<out Out<In<Nothing>>>>; upper: In<Nothing>; substitution: In<Inv<Out<In<Inv<Inv<in Int>>>>>>
+  out Int. lower: In<Inv<out Out<In<Nothing>>>>; upper: In<Nothing>; substitution: In<Inv<Out<In<Inv<Inv<in Int>>>>>>
+
+Out<Inv<Inv<out Inv<Inv<in In<in T>>>>>>
+  in Int. lower: Out<Nothing>; upper: Out<Inv<out Inv<out Inv<out Inv<in In<Any?>>>>>>; substitution: Out<Inv<Inv<out Inv<Inv<in In<Int>>>>>>
+  out Int. lower: Out<Nothing>; upper: Out<Inv<out Inv<out Inv<out Inv<in In<Int>>>>>>; substitution: Out<Inv<Inv<out Inv<Inv<in In<out Any?>>>>>>
+
+Inv<Out<In<In<Inv<in In<in T>>>>>>
+  in Int. lower: Nothing; upper: Inv<out Out<In<In<Inv<in In<Any?>>>>>>; substitution: Inv<Out<In<In<Inv<in In<Int>>>>>>
+  out Int. lower: Nothing; upper: Inv<out Out<In<In<Inv<in In<Int>>>>>>; substitution: Inv<Out<In<In<Inv<in In<out Any?>>>>>>
+
+Inv<In<Inv<Inv<in Inv<out Inv<out in T>>>>>>
+  compiler error
+
+In<Inv<out Inv<in Inv<Inv<in Inv<out in T>>>>>>
+  compiler error
+
+In<Inv<Inv<out Inv<out In<In<in T>>>>>>
+  in Int. lower: In<Inv<out Inv<out Inv<out In<In<Any?>>>>>>; upper: In<Nothing>; substitution: In<Inv<Inv<out Inv<out In<In<Int>>>>>>
+  out Int. lower: In<Inv<out Inv<out Inv<out In<In<Int>>>>>>; upper: In<Nothing>; substitution: In<Inv<Inv<out Inv<out In<In<out Any?>>>>>>
+
+Out<In<Inv<Out<Inv<Out<in T>>>>>>
+  compiler error
+
+Inv<out Inv<Inv<in Out<Inv<out Inv<in in T>>>>>>
+  compiler error
+
+Out<Inv<in Inv<Out<Inv<Out<in T>>>>>>
+  compiler error
+
+Inv<Inv<in Inv<in In<In<Out<in T>>>>>>
+  compiler error
+

compiler/testData/capturedTypeApproximation/useSiteOutNullableT.txt

@@ -0,0 +1,236 @@
+In<out T?>
+  compiler error
+
+Out<out T?>
+  in Int. lower: Out<Int?>; upper: Out<Any?>; substitution: Out<Any?>
+  out Int. lower: Out<Nothing?>; upper: Out<Int?>; substitution: Out<Int?>
+
+Inv<out T?>
+  in Int. lower: Inv<out Int?>; upper: Inv<out Any?>; substitution: Inv<out Int?>
+  out Int. lower: Inv<out Nothing?>; upper: Inv<out Int?>; substitution: Inv<out Int?>
+
+Inv<in out T?>
+  compiler error
+
+Inv<out out T?>
+  compiler error
+
+In<In<out T?>>
+  compiler error
+
+In<Out<out T?>>
+  in Int. lower: In<Out<Any?>>; upper: In<Out<Int?>>; substitution: In<Out<Any?>>
+  out Int. lower: In<Out<Int?>>; upper: In<Out<Nothing?>>; substitution: In<Out<Int?>>
+
+In<Inv<out T?>>
+  in Int. lower: In<Inv<out Any?>>; upper: In<Inv<out Int?>>; substitution: In<Inv<out Int?>>
+  out Int. lower: In<Inv<out Int?>>; upper: In<Inv<out Nothing?>>; substitution: In<Inv<out Int?>>
+
+In<Inv<in out T?>>
+  compiler error
+
+In<Inv<out out T?>>
+  compiler error
+
+Out<In<out T?>>
+  compiler error
+
+Out<Out<out T?>>
+  in Int. lower: Out<Out<Int?>>; upper: Out<Out<Any?>>; substitution: Out<Out<Any?>>
+  out Int. lower: Out<Out<Nothing?>>; upper: Out<Out<Int?>>; substitution: Out<Out<Int?>>
+
+Out<Inv<out T?>>
+  in Int. lower: Out<Inv<out Int?>>; upper: Out<Inv<out Any?>>; substitution: Out<Inv<out Int?>>
+  out Int. lower: Out<Inv<out Nothing?>>; upper: Out<Inv<out Int?>>; substitution: Out<Inv<out Int?>>
+
+Out<Inv<in out T?>>
+  compiler error
+
+Out<Inv<out out T?>>
+  compiler error
+
+Inv<In<out T?>>
+  compiler error
+
+Inv<Out<out T?>>
+  in Int. lower: Nothing; upper: Inv<out Out<Any?>>; substitution: Inv<Out<Any?>>
+  out Int. lower: Nothing; upper: Inv<out Out<Int?>>; substitution: Inv<Out<Int?>>
+
+Inv<Inv<out T?>>
+  in Int. lower: Nothing; upper: Inv<out Inv<out Any?>>; substitution: Inv<Inv<out Int?>>
+  out Int. lower: Nothing; upper: Inv<out Inv<out Int?>>; substitution: Inv<Inv<out Int?>>
+
+Inv<Inv<in out T?>>
+  compiler error
+
+Inv<Inv<out out T?>>
+  compiler error
+
+Inv<in In<out T?>>
+  compiler error
+
+Inv<in Out<out T?>>
+  in Int. lower: Inv<in Out<Any?>>; upper: Inv<in Out<Int?>>; substitution: Inv<in Out<Any?>>
+  out Int. lower: Inv<in Out<Int?>>; upper: Inv<in Out<Nothing?>>; substitution: Inv<in Out<Int?>>
+
+Inv<in Inv<out T?>>
+  in Int. lower: Inv<in Inv<out Any?>>; upper: Inv<in Inv<out Int?>>; substitution: Inv<in Inv<out Int?>>
+  out Int. lower: Inv<in Inv<out Int?>>; upper: Inv<in Inv<out Nothing?>>; substitution: Inv<in Inv<out Int?>>
+
+Inv<in Inv<in out T?>>
+  compiler error
+
+Inv<in Inv<out out T?>>
+  compiler error
+
+Inv<out In<out T?>>
+  compiler error
+
+Inv<out Out<out T?>>
+  in Int. lower: Inv<out Out<Int?>>; upper: Inv<out Out<Any?>>; substitution: Inv<out Out<Any?>>
+  out Int. lower: Inv<out Out<Nothing?>>; upper: Inv<out Out<Int?>>; substitution: Inv<out Out<Int?>>
+
+Inv<out Inv<out T?>>
+  in Int. lower: Inv<out Inv<out Int?>>; upper: Inv<out Inv<out Any?>>; substitution: Inv<out Inv<out Int?>>
+  out Int. lower: Inv<out Inv<out Nothing?>>; upper: Inv<out Inv<out Int?>>; substitution: Inv<out Inv<out Int?>>
+
+Inv<out Inv<in out T?>>
+  compiler error
+
+Inv<out Inv<out out T?>>
+  compiler error
+
+In<Inv<Out<out T?>>>
+  in Int. lower: In<Inv<out Out<Any?>>>; upper: In<Nothing>; substitution: In<Inv<Out<Any?>>>
+  out Int. lower: In<Inv<out Out<Int?>>>; upper: In<Nothing>; substitution: In<Inv<Out<Int?>>>
+
+Out<Out<Out<out T?>>>
+  in Int. lower: Out<Out<Out<Int?>>>; upper: Out<Out<Out<Any?>>>; substitution: Out<Out<Out<Any?>>>
+  out Int. lower: Out<Out<Out<Nothing?>>>; upper: Out<Out<Out<Int?>>>; substitution: Out<Out<Out<Int?>>>
+
+Inv<Inv<in In<out T?>>>
+  compiler error
+
+Inv<out Inv<Out<out T?>>>
+  in Int. lower: Inv<Nothing>; upper: Inv<out Inv<out Out<Any?>>>; substitution: Inv<out Inv<Out<Any?>>>
+  out Int. lower: Inv<Nothing>; upper: Inv<out Inv<out Out<Int?>>>; substitution: Inv<out Inv<Out<Int?>>>
+
+Inv<in Inv<Inv<out T?>>>
+  in Int. lower: Inv<in Inv<out Inv<out Any?>>>; upper: Inv<out Any?>; substitution: Inv<in Inv<Inv<out Int?>>>
+  out Int. lower: Inv<in Inv<out Inv<out Int?>>>; upper: Inv<out Any?>; substitution: Inv<in Inv<Inv<out Int?>>>
+
+Out<Inv<In<out T?>>>
+  compiler error
+
+Inv<out Out<Out<out T?>>>
+  in Int. lower: Inv<out Out<Out<Int?>>>; upper: Inv<out Out<Out<Any?>>>; substitution: Inv<out Out<Out<Any?>>>
+  out Int. lower: Inv<out Out<Out<Nothing?>>>; upper: Inv<out Out<Out<Int?>>>; substitution: Inv<out Out<Out<Int?>>>
+
+Out<In<Inv<out T?>>>
+  in Int. lower: Out<In<Inv<out Any?>>>; upper: Out<In<Inv<out Int?>>>; substitution: Out<In<Inv<out Int?>>>
+  out Int. lower: Out<In<Inv<out Int?>>>; upper: Out<In<Inv<out Nothing?>>>; substitution: Out<In<Inv<out Int?>>>
+
+Inv<out In<Out<out T?>>>
+  in Int. lower: Inv<out In<Out<Any?>>>; upper: Inv<out In<Out<Int?>>>; substitution: Inv<out In<Out<Any?>>>
+  out Int. lower: Inv<out In<Out<Int?>>>; upper: Inv<out In<Out<Nothing?>>>; substitution: Inv<out In<Out<Int?>>>
+
+In<Out<Inv<out T?>>>
+  in Int. lower: In<Out<Inv<out Any?>>>; upper: In<Out<Inv<out Int?>>>; substitution: In<Out<Inv<out Int?>>>
+  out Int. lower: In<Out<Inv<out Int?>>>; upper: In<Out<Inv<out Nothing?>>>; substitution: In<Out<Inv<out Int?>>>
+
+Inv<out Inv<Inv<out Inv<in out T?>>>>
+  compiler error
+
+Inv<in Out<In<Inv<in out T?>>>>
+  compiler error
+
+Inv<in In<Inv<out Inv<in out T?>>>>
+  compiler error
+
+Inv<In<In<Inv<in out T?>>>>
+  compiler error
+
+Inv<out Inv<out Inv<out Inv<out T?>>>>
+  in Int. lower: Inv<out Inv<out Inv<out Inv<out Int?>>>>; upper: Inv<out Inv<out Inv<out Inv<out Any?>>>>; substitution: Inv<out Inv<out Inv<out Inv<out Int?>>>>
+  out Int. lower: Inv<out Inv<out Inv<out Inv<out Nothing?>>>>; upper: Inv<out Inv<out Inv<out Inv<out Int?>>>>; substitution: Inv<out Inv<out Inv<out Inv<out Int?>>>>
+
+Inv<out Out<Inv<out Inv<in out T?>>>>
+  compiler error
+
+Out<Inv<out Inv<out In<out T?>>>>
+  compiler error
+
+In<Inv<in In<Inv<in out T?>>>>
+  compiler error
+
+Out<Inv<in In<Inv<out T?>>>>
+  in Int. lower: Out<Inv<in In<Inv<out Int?>>>>; upper: Out<Inv<in In<Inv<out Any?>>>>; substitution: Out<Inv<in In<Inv<out Int?>>>>
+  out Int. lower: Out<Inv<in In<Inv<out Nothing?>>>>; upper: Out<Inv<in In<Inv<out Int?>>>>; substitution: Out<Inv<in In<Inv<out Int?>>>>
+
+Out<Inv<in Inv<in Inv<out T?>>>>
+  in Int. lower: Out<Inv<in Inv<in Inv<out Int?>>>>; upper: Out<Inv<in Inv<in Inv<out Any?>>>>; substitution: Out<Inv<in Inv<in Inv<out Int?>>>>
+  out Int. lower: Out<Inv<in Inv<in Inv<out Nothing?>>>>; upper: Out<Inv<in Inv<in Inv<out Int?>>>>; substitution: Out<Inv<in Inv<in Inv<out Int?>>>>
+
+In<In<Inv<In<In<out T?>>>>>
+  compiler error
+
+Inv<Inv<Inv<Out<Inv<in out T?>>>>>
+  compiler error
+
+Out<Inv<Out<Out<Inv<out out T?>>>>>
+  compiler error
+
+Inv<In<Inv<in In<Inv<out out T?>>>>>
+  compiler error
+
+Inv<in Inv<out In<Out<Inv<out out T?>>>>>
+  compiler error
+
+Inv<out Out<Inv<in Inv<in Inv<in out T?>>>>>
+  compiler error
+
+Out<Out<Inv<Out<Inv<out out T?>>>>>
+  compiler error
+
+In<Inv<In<In<Inv<out out T?>>>>>
+  compiler error
+
+Inv<out Inv<in Inv<Inv<out Inv<out out T?>>>>>
+  compiler error
+
+In<Inv<in In<In<Inv<out out T?>>>>>
+  compiler error
+
+In<Inv<Out<In<Inv<Inv<out T?>>>>>>
+  in Int. lower: In<Inv<out Out<In<Nothing>>>>; upper: In<Nothing>; substitution: In<Inv<Out<In<Inv<Inv<out Int?>>>>>>
+  out Int. lower: In<Inv<out Out<In<Nothing>>>>; upper: In<Nothing>; substitution: In<Inv<Out<In<Inv<Inv<out Int?>>>>>>
+
+Out<Inv<Inv<out Inv<Inv<in In<out T?>>>>>>
+  compiler error
+
+Inv<Out<In<In<Inv<in In<out T?>>>>>>
+  compiler error
+
+Inv<In<Inv<Inv<in Inv<out Inv<out out T?>>>>>>
+  compiler error
+
+In<Inv<out Inv<in Inv<Inv<in Inv<out out T?>>>>>>
+  compiler error
+
+In<Inv<Inv<out Inv<out In<In<out T?>>>>>>
+  compiler error
+
+Out<In<Inv<Out<Inv<Out<out T?>>>>>>
+  in Int. lower: Out<In<Inv<out Out<Inv<out Out<Any?>>>>>>; upper: Out<In<Nothing>>; substitution: Out<In<Inv<Out<Inv<Out<Any?>>>>>>
+  out Int. lower: Out<In<Inv<out Out<Inv<out Out<Int?>>>>>>; upper: Out<In<Nothing>>; substitution: Out<In<Inv<Out<Inv<Out<Int?>>>>>>
+
+Inv<out Inv<Inv<in Out<Inv<out Inv<in out T?>>>>>>
+  compiler error
+
+Out<Inv<in Inv<Out<Inv<Out<out T?>>>>>>
+  in Int. lower: Out<Inv<in Inv<out Out<Inv<out Out<Any?>>>>>>; upper: Out<Inv<out Any?>>; substitution: Out<Inv<in Inv<Out<Inv<Out<Any?>>>>>>
+  out Int. lower: Out<Inv<in Inv<out Out<Inv<out Out<Int?>>>>>>; upper: Out<Inv<out Any?>>; substitution: Out<Inv<in Inv<Out<Inv<Out<Int?>>>>>>
+
+Inv<Inv<in Inv<in In<In<Out<out T?>>>>>>
+  in Int. lower: Nothing; upper: Inv<out Inv<in Inv<in In<In<Out<Any?>>>>>>; substitution: Inv<Inv<in Inv<in In<In<Out<Any?>>>>>>
+  out Int. lower: Nothing; upper: Inv<out Inv<in Inv<in In<In<Out<Int?>>>>>>; substitution: Inv<Inv<in Inv<in In<In<Out<Int?>>>>>>

compiler/testData/capturedTypeApproximation/useSiteOutT.txt

@@ -0,0 +1,236 @@
+In<out T>
+  compiler error
+
+Out<out T>
+  in Int. lower: Out<Int>; upper: Out<Any?>; substitution: Out<Any?>
+  out Int. lower: Out<Nothing>; upper: Out<Int>; substitution: Out<Int>
+
+Inv<out T>
+  in Int. lower: Inv<out Int>; upper: Inv<out Any?>; substitution: Inv<out Int>
+  out Int. lower: Inv<Nothing>; upper: Inv<out Int>; substitution: Inv<out Int>
+
+Inv<in out T>
+  compiler error
+
+Inv<out out T>
+  compiler error
+
+In<In<out T>>
+  compiler error
+
+In<Out<out T>>
+  in Int. lower: In<Out<Any?>>; upper: In<Out<Int>>; substitution: In<Out<Any?>>
+  out Int. lower: In<Out<Int>>; upper: In<Out<Nothing>>; substitution: In<Out<Int>>
+
+In<Inv<out T>>
+  in Int. lower: In<Inv<out Any?>>; upper: In<Inv<out Int>>; substitution: In<Inv<out Int>>
+  out Int. lower: In<Inv<out Int>>; upper: In<Inv<Nothing>>; substitution: In<Inv<out Int>>
+
+In<Inv<in out T>>
+  compiler error
+
+In<Inv<out out T>>
+  compiler error
+
+Out<In<out T>>
+  compiler error
+
+Out<Out<out T>>
+  in Int. lower: Out<Out<Int>>; upper: Out<Out<Any?>>; substitution: Out<Out<Any?>>
+  out Int. lower: Out<Out<Nothing>>; upper: Out<Out<Int>>; substitution: Out<Out<Int>>
+
+Out<Inv<out T>>
+  in Int. lower: Out<Inv<out Int>>; upper: Out<Inv<out Any?>>; substitution: Out<Inv<out Int>>
+  out Int. lower: Out<Inv<Nothing>>; upper: Out<Inv<out Int>>; substitution: Out<Inv<out Int>>
+
+Out<Inv<in out T>>
+  compiler error
+
+Out<Inv<out out T>>
+  compiler error
+
+Inv<In<out T>>
+  compiler error
+
+Inv<Out<out T>>
+  in Int. lower: Nothing; upper: Inv<out Out<Any?>>; substitution: Inv<Out<Any?>>
+  out Int. lower: Nothing; upper: Inv<out Out<Int>>; substitution: Inv<Out<Int>>
+
+Inv<Inv<out T>>
+  in Int. lower: Nothing; upper: Inv<out Inv<out Any?>>; substitution: Inv<Inv<out Int>>
+  out Int. lower: Nothing; upper: Inv<out Inv<out Int>>; substitution: Inv<Inv<out Int>>
+
+Inv<Inv<in out T>>
+  compiler error
+
+Inv<Inv<out out T>>
+  compiler error
+
+Inv<in In<out T>>
+  compiler error
+
+Inv<in Out<out T>>
+  in Int. lower: Inv<in Out<Any?>>; upper: Inv<in Out<Int>>; substitution: Inv<in Out<Any?>>
+  out Int. lower: Inv<in Out<Int>>; upper: Inv<in Out<Nothing>>; substitution: Inv<in Out<Int>>
+
+Inv<in Inv<out T>>
+  in Int. lower: Inv<in Inv<out Any?>>; upper: Inv<in Inv<out Int>>; substitution: Inv<in Inv<out Int>>
+  out Int. lower: Inv<in Inv<out Int>>; upper: Inv<in Inv<Nothing>>; substitution: Inv<in Inv<out Int>>
+
+Inv<in Inv<in out T>>
+  compiler error
+
+Inv<in Inv<out out T>>
+  compiler error
+
+Inv<out In<out T>>
+  compiler error
+
+Inv<out Out<out T>>
+  in Int. lower: Inv<out Out<Int>>; upper: Inv<out Out<Any?>>; substitution: Inv<out Out<Any?>>
+  out Int. lower: Inv<out Out<Nothing>>; upper: Inv<out Out<Int>>; substitution: Inv<out Out<Int>>
+
+Inv<out Inv<out T>>
+  in Int. lower: Inv<out Inv<out Int>>; upper: Inv<out Inv<out Any?>>; substitution: Inv<out Inv<out Int>>
+  out Int. lower: Inv<out Inv<Nothing>>; upper: Inv<out Inv<out Int>>; substitution: Inv<out Inv<out Int>>
+
+Inv<out Inv<in out T>>
+  compiler error
+
+Inv<out Inv<out out T>>
+  compiler error
+
+In<Inv<Out<out T>>>
+  in Int. lower: In<Inv<out Out<Any?>>>; upper: In<Nothing>; substitution: In<Inv<Out<Any?>>>
+  out Int. lower: In<Inv<out Out<Int>>>; upper: In<Nothing>; substitution: In<Inv<Out<Int>>>
+
+Out<Out<Out<out T>>>
+  in Int. lower: Out<Out<Out<Int>>>; upper: Out<Out<Out<Any?>>>; substitution: Out<Out<Out<Any?>>>
+  out Int. lower: Out<Out<Out<Nothing>>>; upper: Out<Out<Out<Int>>>; substitution: Out<Out<Out<Int>>>
+
+Inv<Inv<in In<out T>>>
+  compiler error
+
+Inv<out Inv<Out<out T>>>
+  in Int. lower: Inv<Nothing>; upper: Inv<out Inv<out Out<Any?>>>; substitution: Inv<out Inv<Out<Any?>>>
+  out Int. lower: Inv<Nothing>; upper: Inv<out Inv<out Out<Int>>>; substitution: Inv<out Inv<Out<Int>>>
+
+Inv<in Inv<Inv<out T>>>
+  in Int. lower: Inv<in Inv<out Inv<out Any?>>>; upper: Inv<out Any?>; substitution: Inv<in Inv<Inv<out Int>>>
+  out Int. lower: Inv<in Inv<out Inv<out Int>>>; upper: Inv<out Any?>; substitution: Inv<in Inv<Inv<out Int>>>
+
+Out<Inv<In<out T>>>
+  compiler error
+
+Inv<out Out<Out<out T>>>
+  in Int. lower: Inv<out Out<Out<Int>>>; upper: Inv<out Out<Out<Any?>>>; substitution: Inv<out Out<Out<Any?>>>
+  out Int. lower: Inv<out Out<Out<Nothing>>>; upper: Inv<out Out<Out<Int>>>; substitution: Inv<out Out<Out<Int>>>
+
+Out<In<Inv<out T>>>
+  in Int. lower: Out<In<Inv<out Any?>>>; upper: Out<In<Inv<out Int>>>; substitution: Out<In<Inv<out Int>>>
+  out Int. lower: Out<In<Inv<out Int>>>; upper: Out<In<Inv<Nothing>>>; substitution: Out<In<Inv<out Int>>>
+
+Inv<out In<Out<out T>>>
+  in Int. lower: Inv<out In<Out<Any?>>>; upper: Inv<out In<Out<Int>>>; substitution: Inv<out In<Out<Any?>>>
+  out Int. lower: Inv<out In<Out<Int>>>; upper: Inv<out In<Out<Nothing>>>; substitution: Inv<out In<Out<Int>>>
+
+In<Out<Inv<out T>>>
+  in Int. lower: In<Out<Inv<out Any?>>>; upper: In<Out<Inv<out Int>>>; substitution: In<Out<Inv<out Int>>>
+  out Int. lower: In<Out<Inv<out Int>>>; upper: In<Out<Inv<Nothing>>>; substitution: In<Out<Inv<out Int>>>
+
+Inv<out Inv<Inv<out Inv<in out T>>>>
+  compiler error
+
+Inv<in Out<In<Inv<in out T>>>>
+  compiler error
+
+Inv<in In<Inv<out Inv<in out T>>>>
+  compiler error
+
+Inv<In<In<Inv<in out T>>>>
+  compiler error
+
+Inv<out Inv<out Inv<out Inv<out T>>>>
+  in Int. lower: Inv<out Inv<out Inv<out Inv<out Int>>>>; upper: Inv<out Inv<out Inv<out Inv<out Any?>>>>; substitution: Inv<out Inv<out Inv<out Inv<out Int>>>>
+  out Int. lower: Inv<out Inv<out Inv<out Inv<Nothing>>>>; upper: Inv<out Inv<out Inv<out Inv<out Int>>>>; substitution: Inv<out Inv<out Inv<out Inv<out Int>>>>
+
+Inv<out Out<Inv<out Inv<in out T>>>>
+  compiler error
+
+Out<Inv<out Inv<out In<out T>>>>
+  compiler error
+
+In<Inv<in In<Inv<in out T>>>>
+  compiler error
+
+Out<Inv<in In<Inv<out T>>>>
+  in Int. lower: Out<Inv<in In<Inv<out Int>>>>; upper: Out<Inv<in In<Inv<out Any?>>>>; substitution: Out<Inv<in In<Inv<out Int>>>>
+  out Int. lower: Out<Inv<in In<Inv<Nothing>>>>; upper: Out<Inv<in In<Inv<out Int>>>>; substitution: Out<Inv<in In<Inv<out Int>>>>
+
+Out<Inv<in Inv<in Inv<out T>>>>
+  in Int. lower: Out<Inv<in Inv<in Inv<out Int>>>>; upper: Out<Inv<in Inv<in Inv<out Any?>>>>; substitution: Out<Inv<in Inv<in Inv<out Int>>>>
+  out Int. lower: Out<Inv<in Inv<in Inv<Nothing>>>>; upper: Out<Inv<in Inv<in Inv<out Int>>>>; substitution: Out<Inv<in Inv<in Inv<out Int>>>>
+
+In<In<Inv<In<In<out T>>>>>
+  compiler error
+
+Inv<Inv<Inv<Out<Inv<in out T>>>>>
+  compiler error
+
+Out<Inv<Out<Out<Inv<out out T>>>>>
+  compiler error
+
+Inv<In<Inv<in In<Inv<out out T>>>>>
+  compiler error
+
+Inv<in Inv<out In<Out<Inv<out out T>>>>>
+  compiler error
+
+Inv<out Out<Inv<in Inv<in Inv<in out T>>>>>
+  compiler error
+
+Out<Out<Inv<Out<Inv<out out T>>>>>
+  compiler error
+
+In<Inv<In<In<Inv<out out T>>>>>
+  compiler error
+
+Inv<out Inv<in Inv<Inv<out Inv<out out T>>>>>
+  compiler error
+
+In<Inv<in In<In<Inv<out out T>>>>>
+  compiler error
+
+In<Inv<Out<In<Inv<Inv<out T>>>>>>
+  in Int. lower: In<Inv<out Out<In<Nothing>>>>; upper: In<Nothing>; substitution: In<Inv<Out<In<Inv<Inv<out Int>>>>>>
+  out Int. lower: In<Inv<out Out<In<Nothing>>>>; upper: In<Nothing>; substitution: In<Inv<Out<In<Inv<Inv<out Int>>>>>>
+
+Out<Inv<Inv<out Inv<Inv<in In<out T>>>>>>
+  compiler error
+
+Inv<Out<In<In<Inv<in In<out T>>>>>>
+  compiler error
+
+Inv<In<Inv<Inv<in Inv<out Inv<out out T>>>>>>
+  compiler error
+
+In<Inv<out Inv<in Inv<Inv<in Inv<out out T>>>>>>
+  compiler error
+
+In<Inv<Inv<out Inv<out In<In<out T>>>>>>
+  compiler error
+
+Out<In<Inv<Out<Inv<Out<out T>>>>>>
+  in Int. lower: Out<In<Inv<out Out<Inv<out Out<Any?>>>>>>; upper: Out<In<Nothing>>; substitution: Out<In<Inv<Out<Inv<Out<Any?>>>>>>
+  out Int. lower: Out<In<Inv<out Out<Inv<out Out<Int>>>>>>; upper: Out<In<Nothing>>; substitution: Out<In<Inv<Out<Inv<Out<Int>>>>>>
+
+Inv<out Inv<Inv<in Out<Inv<out Inv<in out T>>>>>>
+  compiler error
+
+Out<Inv<in Inv<Out<Inv<Out<out T>>>>>>
+  in Int. lower: Out<Inv<in Inv<out Out<Inv<out Out<Any?>>>>>>; upper: Out<Inv<out Any?>>; substitution: Out<Inv<in Inv<Out<Inv<Out<Any?>>>>>>
+  out Int. lower: Out<Inv<in Inv<out Out<Inv<out Out<Int>>>>>>; upper: Out<Inv<out Any?>>; substitution: Out<Inv<in Inv<Out<Inv<Out<Int>>>>>>
+
+Inv<Inv<in Inv<in In<In<Out<out T>>>>>>
+  in Int. lower: Nothing; upper: Inv<out Inv<in Inv<in In<In<Out<Any?>>>>>>; substitution: Inv<Inv<in Inv<in In<In<Out<Any?>>>>>>
+  out Int. lower: Nothing; upper: Inv<out Inv<in Inv<in In<In<Out<Int>>>>>>; substitution: Inv<Inv<in Inv<in In<In<Out<Int>>>>>>

compiler/testData/capturedTypeApproximation/useSiteVarianceIn.kt

@@ -1,11 +0,0 @@
-class Inv<T>
-
-fun foo<T>(a: Inv<in T>) {}
-
-// T captures 'in Int'
-// lower: Inv<Any?>
-// upper: Inv<in Int>
-
-// T captures 'out Int'
-// lower: Inv<in Int>
-// upper: Inv<out Any?>

compiler/testData/capturedTypeApproximation/useSiteVarianceOut.kt

@@ -1,11 +0,0 @@
-class Inv<T>
-
-fun foo<T>(a: Inv<out T>) {}
-
-// T captures 'in Int'
-// lower: Inv<out Int>
-// upper: Inv<out Any?>
-
-// T captures 'out Int'
-// lower: Inv<Nothing>
-// upper: Inv<out Int>

compiler/tests/org/jetbrains/jet/resolve/typeApproximation/AbstractCapturedTypeApproximationTest.kt

@@ -1,75 +0,0 @@
-/*
- * Copyright 2010-2014 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.jetbrains.jet.resolve.typeApproximation
-
-import org.jetbrains.jet.JetLiteFixture
-import org.jetbrains.jet.cli.jvm.compiler.JetCoreEnvironment
-import org.jetbrains.jet.ConfigurationKind
-import java.io.File
-import org.jetbrains.jet.lang.resolve.lazy.JvmResolveUtil
-import org.jetbrains.jet.lang.resolve.BindingContext
-import org.jetbrains.jet.lang.descriptors.FunctionDescriptor
-import org.jetbrains.jet.lang.types.TypeSubstitutor
-import org.jetbrains.jet.lang.types.TypeProjectionImpl
-import org.jetbrains.jet.lang.types.lang.KotlinBuiltIns
-import org.jetbrains.jet.lang.types.Variance
-import org.jetbrains.jet.lang.types.typesApproximation.approximateCapturedTypes
-import org.jetbrains.jet.JetTestUtils
-import org.jetbrains.jet.lang.psi.JetPsiFactory
-import org.jetbrains.jet.lang.resolve.calls.inference.CapturedTypeConstructor
-import org.jetbrains.jet.lang.types.JetTypeImpl
-import org.jetbrains.jet.lang.resolve.calls.inference.createCapturedType
-
-abstract public class AbstractCapturedTypeApproximationTest() : JetLiteFixture() {
-    override fun createEnvironment(): JetCoreEnvironment = createEnvironmentWithMockJdk(ConfigurationKind.ALL)
-
-    public fun doTest(filePath: String) {
-        val file = File(filePath)
-        val text = JetTestUtils.doLoadFile(file)!!
-
-        val jetFile = JetPsiFactory(getProject()).createFile(text)
-        val bindingContext = JvmResolveUtil.analyzeOneFileWithJavaIntegration(jetFile).bindingContext
-
-        val functions = bindingContext.getSliceContents(BindingContext.FUNCTION)
-        val functionFoo = functions.values().firstOrNull { it.getName().asString() == "foo" } ?:
-                          throw AssertionError("Function 'foo' is not declared")
-        val typeParameter = functionFoo.getTypeParameters().first()
-        val parameter = functionFoo.getValueParameters().first().getType()
-
-        val result = StringBuilder {
-            val endIndex = text.indexOf("// T captures")
-            appendln(if (endIndex == -1) text else text.substring(0, endIndex).trimTrailing())
-
-            for (variance in listOf(Variance.IN_VARIANCE, Variance.OUT_VARIANCE)) {
-
-                val captured = createCapturedType(TypeProjectionImpl(variance, KotlinBuiltIns.getInstance().getIntType()))
-                val typeSubstitutor = TypeSubstitutor.create(mapOf(typeParameter.getTypeConstructor() to TypeProjectionImpl(captured)))
-                val typeWithCapturedType = typeSubstitutor.substituteWithoutApproximation(
-                        TypeProjectionImpl(Variance.INVARIANT, parameter))!!.getType()
-
-                val (lower, upper) = approximateCapturedTypes(typeWithCapturedType)
-
-                appendln()
-                appendln("// T captures '${(captured.getConstructor() as CapturedTypeConstructor).typeProjection}'")
-                appendln("// lower: $lower")
-                appendln("// upper: $upper")
-            }
-        }.toString()
-
-        JetTestUtils.assertEqualsToFile(file, result)
-    }
-}

compiler/tests/org/jetbrains/jet/resolve/typeApproximation/CapturedTypeApproximationTest.kt

@@ -0,0 +1,199 @@
+/*
+ * Copyright 2010-2014 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.jet.resolve.typeApproximation
+
+import org.jetbrains.jet.JetLiteFixture
+import org.jetbrains.jet.cli.jvm.compiler.JetCoreEnvironment
+import org.jetbrains.jet.ConfigurationKind
+import java.io.File
+import org.jetbrains.jet.lang.resolve.lazy.JvmResolveUtil
+import org.jetbrains.jet.lang.resolve.BindingContext
+import org.jetbrains.jet.lang.types.TypeSubstitutor
+import org.jetbrains.jet.lang.types.TypeProjectionImpl
+import org.jetbrains.jet.lang.types.lang.KotlinBuiltIns
+import org.jetbrains.jet.lang.types.Variance
+import org.jetbrains.jet.lang.types.Variance.*
+import org.jetbrains.jet.lang.types.typesApproximation.approximateCapturedTypes
+import org.jetbrains.jet.JetTestUtils
+import org.jetbrains.jet.lang.psi.JetPsiFactory
+import org.jetbrains.jet.lang.resolve.calls.inference.CapturedTypeConstructor
+import org.jetbrains.jet.lang.resolve.calls.inference.createCapturedType
+import org.jetbrains.jet.lang.diagnostics.Severity
+import org.jetbrains.jet.lang.types.typesApproximation.approximateCapturedTypesIfNecessary
+import java.util.ArrayList
+import org.jetbrains.jet.lang.types.TypeProjection
+import org.jetbrains.jet.lang.descriptors.TypeParameterDescriptor
+
+public class CapturedTypeApproximationTest() : JetLiteFixture() {
+
+    override fun getTestDataPath() = "compiler/testData/capturedTypeApproximation/"
+
+    override fun createEnvironment(): JetCoreEnvironment = createEnvironmentWithMockJdk(ConfigurationKind.JDK_ONLY)
+
+    public fun doTest(filePath: String, vararg substitutions: String) {
+        assert(substitutions.size() in 1..2, "Captured type approximation test requires substitutions for (T) or (T, R)")
+        val oneTypeVariable = substitutions.size() == 1
+
+        val declarationsText = JetTestUtils.doLoadFile(File(getTestDataPath() + "/declarations.kt"))
+
+        fun analyzeTestFile(testType: String) = run {
+            val test = declarationsText.replace("#TestType#", testType)
+            val testFile = JetPsiFactory(getProject()).createFile(test)
+            val bindingContext = JvmResolveUtil.analyzeOneFileWithJavaIntegration(testFile).bindingContext
+            val functions = bindingContext.getSliceContents(BindingContext.FUNCTION)
+            val functionFoo = functions.values().firstOrNull { it.getName().asString() == "foo" } ?:
+                              throw AssertionError("Function 'foo' is not declared")
+            Pair(bindingContext, functionFoo)
+        }
+
+        fun createTestType(testTypeWithT: String): String {
+            val testType = testTypeWithT.replace("#T#", substitutions[0])
+            if (oneTypeVariable) return testType
+            return testType.replace("#R#", substitutions[1])
+        }
+
+        fun createTestSubstitutions(typeParameters: List<TypeParameterDescriptor>) = run {
+            val intType = KotlinBuiltIns.getInstance().getIntType()
+            val stringType = KotlinBuiltIns.getInstance().getStringType()
+            val t = typeParameters[0]
+            val r = typeParameters[1]
+            if (oneTypeVariable)
+                listOf(mapOf(t to TypeProjectionImpl(IN_VARIANCE, intType)),
+                       mapOf(t to TypeProjectionImpl(OUT_VARIANCE, intType)))
+            else {
+                listOf(mapOf(
+                        t to TypeProjectionImpl(IN_VARIANCE, intType),
+                        r to TypeProjectionImpl(OUT_VARIANCE, stringType))
+                )
+            }
+        }
+
+        fun createTestSubstitutor(testSubstitution: Map<TypeParameterDescriptor, TypeProjection>): TypeSubstitutor {
+            val substitutionContext = testSubstitution.map {
+                val (typeParameter, typeProjection) = it
+                typeParameter.getTypeConstructor() to TypeProjectionImpl(createCapturedType(typeProjection))
+            }.toMap()
+            return TypeSubstitutor.create(substitutionContext)
+        }
+
+        val testTypes = if (oneTypeVariable) getTestTypesForOneTypeVariable() else getTestTypesForTwoTypeVariables()
+        val result = StringBuilder {
+            for ((index, testTypeWithUnsubstitutedTypeVars) in testTypes.withIndex()) {
+                val testType = createTestType(testTypeWithUnsubstitutedTypeVars)
+                val (bindingContext, functionFoo) = analyzeTestFile(testType)
+                val typeParameters = functionFoo.getTypeParameters()
+                val type = functionFoo.getReturnType()
+
+                appendln(testType)
+
+                if (bindingContext.getDiagnostics().any { it.getSeverity() == Severity.ERROR }) {
+                    appendln("  compiler error\n")
+                    continue
+                }
+
+                val testSubstitutions = createTestSubstitutions(typeParameters)
+                for (testSubstitution in testSubstitutions) {
+                    val typeSubstitutor = createTestSubstitutor(testSubstitution)
+                    val typeWithCapturedType = typeSubstitutor.substituteWithoutApproximation(TypeProjectionImpl(INVARIANT, type))!!.getType()
+
+                    val (lower, upper) = approximateCapturedTypes(typeWithCapturedType)
+                    val substitution = approximateCapturedTypesIfNecessary(TypeProjectionImpl(INVARIANT, typeWithCapturedType))
+
+                    append("  ")
+                    for (typeParameter in testSubstitution.keySet()) {
+                        if (testSubstitution.size() > 1) append("${typeParameter.getName()} = ")
+                        append("${testSubstitution[typeParameter]}. ")
+                    }
+                    appendln("lower: $lower; upper: $upper; substitution: $substitution")
+                }
+                if (testTypes.lastIndex != index) appendln()
+            }
+        }
+
+        JetTestUtils.assertEqualsToFile(File(getTestDataPath() + "/" + filePath), result.toString())
+    }
+
+    private fun getTypePatternsForOneTypeVariable() = listOf("In<#T#>", "Out<#T#>", "Inv<#T#>", "Inv<in #T#>", "Inv<out #T#>")
+    private fun getTypePatternsForTwoTypeVariables() = listOf("Fun<#T#, #R#>", "Inv2<#T#, #R#>")
+
+    private fun getTestTypesForOneTypeVariable(): List<String> {
+        val typePatterns = getTypePatternsForOneTypeVariable()
+
+        val range = typePatterns.size().indices
+        val variants = ArrayList<List<Int>>()
+        for (i in range) variants.add(listOf(i))
+        for (i in range) for (j in range) variants.add(listOf(i, j))
+
+        fun addRandomVariants(vararg randomVariants: String) {
+            variants.addAll(randomVariants.map { digits -> digits.map { digit -> digit - '0' } })
+        }
+        assert (typePatterns.size() == 5, "Generated random variants below depend on size 5")
+        //From 021 the following is generated: In<Inv<Out<T>>>, where In = typePatterns[0], Inv = typePatterns[2], Out = typePatterns[1]
+        addRandomVariants("021", "111", "230", "421", "322", "120", "411", "102", "401", "012")
+        addRandomVariants("4243", "3103", "3043", "2003", "4442", "4143", "1440", "0303", "1302", "1332")
+        addRandomVariants("00200", "22213", "12114", "20304", "34014", "41333", "11214", "02004", "43244", "03004")
+        addRandomVariants("021022", "124230", "210030", "202344", "043234", "024400", "102121", "423143", "132121", "233001")
+
+        return variants.map { it.fold("#T#") {(type, index) -> type.replace("#T#", typePatterns[index]) } }
+    }
+
+    private fun getTestTypesForTwoTypeVariables(): List<String> {
+        val typePatterns = getTypePatternsForOneTypeVariable()
+
+        val range = typePatterns.size().indices
+        val result = ArrayList<String>()
+        for (pattern in getTypePatternsForTwoTypeVariables()) {
+            for (i in range) {
+                result.add(typePatterns[i].replace("#T#", pattern))
+            }
+            for (i in range) {
+                for (j in range) {
+                    result.add(pattern.replace("#T#", typePatterns[i]).replace("#R#", typePatterns[j].replace("#T#", "#R#")))
+                }
+            }
+        }
+        return result
+    }
+
+    public fun testSimpleT() {
+        doTest("simpleT.txt", "T");
+    }
+
+    public fun testNullableT() {
+        doTest("nullableT.txt", "T?")
+    }
+
+    public fun testUseSiteInT() {
+        doTest("useSiteInT.txt", "in T");
+    }
+
+    public fun testUseSiteInNullableT() {
+        doTest("useSiteInNullableT.txt", "in T?");
+    }
+
+    public fun testUseSiteOutT() {
+        doTest("useSiteOutT.txt", "out T");
+    }
+
+    public fun testUseSiteOutNullableT() {
+        doTest("useSiteOutNullableT.txt", "out T?");
+    }
+
+    public fun testTwoVariables() {
+        doTest("twoVariables.txt", "T", "R")
+    }
+}

compiler/tests/org/jetbrains/jet/resolve/typeApproximation/CapturedTypeApproximationTestGenerated.java

@@ -1,92 +0,0 @@
-/*
- * Copyright 2010-2014 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.jetbrains.jet.resolve.typeApproximation;
-
-import com.intellij.testFramework.TestDataPath;
-import org.jetbrains.jet.JUnit3RunnerWithInners;
-import org.jetbrains.jet.JetTestUtils;
-import org.jetbrains.jet.test.InnerTestClasses;
-import org.jetbrains.jet.test.TestMetadata;
-import org.junit.runner.RunWith;
-
-import java.io.File;
-import java.util.regex.Pattern;
-
-/** This class is generated by {@link org.jetbrains.jet.generators.tests.TestsPackage}. DO NOT MODIFY MANUALLY */
-@SuppressWarnings("all")
-@TestMetadata("compiler/testData/capturedTypeApproximation")
-@TestDataPath("$PROJECT_ROOT")
-@RunWith(JUnit3RunnerWithInners.class)
-public class CapturedTypeApproximationTestGenerated extends AbstractCapturedTypeApproximationTest {
-    public void testAllFilesPresentInCapturedTypeApproximation() throws Exception {
-        JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/capturedTypeApproximation"), Pattern.compile("^(.+)\\.kt$"), true);
-    }
-
-    @TestMetadata("contravariant.kt")
-    public void testContravariant() throws Exception {
-        String fileName = JetTestUtils.navigationMetadata("compiler/testData/capturedTypeApproximation/contravariant.kt");
-        doTest(fileName);
-    }
-
-    @TestMetadata("covariant.kt")
-    public void testCovariant() throws Exception {
-        String fileName = JetTestUtils.navigationMetadata("compiler/testData/capturedTypeApproximation/covariant.kt");
-        doTest(fileName);
-    }
-
-    @TestMetadata("invariant.kt")
-    public void testInvariant() throws Exception {
-        String fileName = JetTestUtils.navigationMetadata("compiler/testData/capturedTypeApproximation/invariant.kt");
-        doTest(fileName);
-    }
-
-    @TestMetadata("nestedCov.kt")
-    public void testNestedCov() throws Exception {
-        String fileName = JetTestUtils.navigationMetadata("compiler/testData/capturedTypeApproximation/nestedCov.kt");
-        doTest(fileName);
-    }
-
-    @TestMetadata("nestedInv.kt")
-    public void testNestedInv() throws Exception {
-        String fileName = JetTestUtils.navigationMetadata("compiler/testData/capturedTypeApproximation/nestedInv.kt");
-        doTest(fileName);
-    }
-
-    @TestMetadata("nestedInvLevel2.kt")
-    public void testNestedInvLevel2() throws Exception {
-        String fileName = JetTestUtils.navigationMetadata("compiler/testData/capturedTypeApproximation/nestedInvLevel2.kt");
-        doTest(fileName);
-    }
-
-    @TestMetadata("nullableTypeVariable.kt")
-    public void testNullableTypeVariable() throws Exception {
-        String fileName = JetTestUtils.navigationMetadata("compiler/testData/capturedTypeApproximation/nullableTypeVariable.kt");
-        doTest(fileName);
-    }
-
-    @TestMetadata("useSiteVarianceIn.kt")
-    public void testUseSiteVarianceIn() throws Exception {
-        String fileName = JetTestUtils.navigationMetadata("compiler/testData/capturedTypeApproximation/useSiteVarianceIn.kt");
-        doTest(fileName);
-    }
-
-    @TestMetadata("useSiteVarianceOut.kt")
-    public void testUseSiteVarianceOut() throws Exception {
-        String fileName = JetTestUtils.navigationMetadata("compiler/testData/capturedTypeApproximation/useSiteVarianceOut.kt");
-        doTest(fileName);
-    }
-}

core/descriptors/src/org/jetbrains/jet/lang/types/CapturedTypeApproximation.kt

@@ -51,17 +51,15 @@ private val NULLABLE_ANY = KotlinBuiltIns.getInstance().getNullableAnyType()
 
 private val NOTHING = KotlinBuiltIns.getInstance().getNothingType()
 
-private val NULLABLE_NOTHING = KotlinBuiltIns.getInstance().getNullableNothingType()
-
 private fun TypeArgument.toTypeProjection(): TypeProjection {
     assert(isConsistent) { "Only consistent enhanced type propection can be converted to type projection" }
     fun removeProjectionIfRedundant(variance: Variance) = if (variance == typeParameter.getVariance()) Variance.INVARIANT else variance
     return when {
         inProjection == outProjection -> TypeProjectionImpl(inProjection)
-        (inProjection == NOTHING || inProjection == NULLABLE_NOTHING) && typeParameter.getVariance() != Variance.IN_VARIANCE ->
+        inProjection == NOTHING && typeParameter.getVariance() != Variance.IN_VARIANCE ->
             TypeProjectionImpl(removeProjectionIfRedundant(Variance.OUT_VARIANCE), outProjection)
         outProjection == NULLABLE_ANY -> TypeProjectionImpl(removeProjectionIfRedundant(Variance.IN_VARIANCE), inProjection)
-        else -> throw AssertionError("Enhanced type projection can't be converted to type projection: $this")
+        else -> TypeProjectionImpl(removeProjectionIfRedundant(Variance.OUT_VARIANCE), outProjection)
     }
 }
 

generators/src/org/jetbrains/jet/generators/tests/GenerateTests.kt

@@ -116,7 +116,6 @@ import org.jetbrains.jet.lang.resolve.java.AbstractJavaTypeSubstitutorTest
 import org.jetbrains.jet.plugin.intentions.declarations.AbstractJoinLinesTest
 import org.jetbrains.jet.codegen.AbstractScriptCodegenTest
 import org.jetbrains.jet.plugin.parameterInfo.AbstractFunctionParameterInfoTest
-import org.jetbrains.jet.resolve.typeApproximation.AbstractCapturedTypeApproximationTest
 import org.jetbrains.jet.psi.patternMatching.AbstractJetPsiUnifierTest
 import org.jetbrains.jet.completion.weighers.AbstractBasicCompletionWeigherTest
 import org.jetbrains.jet.completion.weighers.AbstractSmartCompletionWeigherTest
@@ -172,10 +171,6 @@ fun main(args: Array<String>) {
             model("constraintSystem", extension = "bounds")
         }
 
-        testClass(javaClass<AbstractCapturedTypeApproximationTest>()) {
-            model("capturedTypeApproximation")
-        }
-
         testClass(javaClass<AbstractJetParsingTest>()) {
             model("psi", testMethod = "doParsingTest", pattern = "^(.*)\\.kts?$")
             model("parseCodeFragment/expression", testMethod = "doExpressionCodeFragmentParsingTest", extension = "kt")