diff options
Diffstat (limited to 'test/files/pos')
-rw-r--r-- | test/files/pos/t4881.scala | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/test/files/pos/t4881.scala b/test/files/pos/t4881.scala new file mode 100644 index 0000000000..46cfad9793 --- /dev/null +++ b/test/files/pos/t4881.scala @@ -0,0 +1,31 @@ +class Contra[-T] +trait A +trait B extends A +trait C extends B + +// test improved variance inference: first try formals to see in which variance positions the type param appears; +// only when that fails to determine variance, look at result type +object Test { + def contraLBUB[a >: C <: A](): Contra[a] = null + def contraLB[a >: C](): Contra[a] = null + +{ + val x = contraLBUB() //inferred Contra[C] instead of Contra[A] + val x1: Contra[A] = x +} + +{ + val x = contraLB() //inferred Contra[C] instead of Contra[Any] + val x1: Contra[Any] = x +} + +{ + val x = contraLBUB // make sure it does the same thing as its ()-less counterpart + val x1: Contra[A] = x +} + +{ + val x = contraLB + val x1: Contra[Any] = x +} +} |