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author | Jason Zaugg <jzaugg@gmail.com> | 2013-03-09 13:03:22 +0100 |
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committer | Jason Zaugg <jzaugg@gmail.com> | 2013-03-09 23:05:52 +0100 |
commit | 7e52fb910b8547930f203233e46140a2daf8b511 (patch) | |
tree | dccdea4814193953de9cb92886586dede4a14b4b /test/files/pos/t7226.scala | |
parent | 2ff7650fb9f337dd123449e6cbcefc521cac8556 (diff) | |
download | scala-7e52fb910b8547930f203233e46140a2daf8b511.tar.gz scala-7e52fb910b8547930f203233e46140a2daf8b511.tar.bz2 scala-7e52fb910b8547930f203233e46140a2daf8b511.zip |
SI-7226 Fix inference regression caused by TypeVar equality.
TypeVars, being mutable creatures, mustn't have structural
equality/hashing, otherwise TypeRefs that differ only by
having distinct TypeVars as components get wrongly uniqued
together.
The reported bug showed the disaterous consequences: constraints
from the `C?[Int]` in the return type applied to the `?C[?A]` in
the parameter list.
This commit overrides `equals` and `hashCode` in `TypeVar`
to use reference equality. An alternative fix would be to drop
the `case`-ness of the class, as was the case before 0cde930b
when this regressed.
Diffstat (limited to 'test/files/pos/t7226.scala')
-rw-r--r-- | test/files/pos/t7226.scala | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/test/files/pos/t7226.scala b/test/files/pos/t7226.scala new file mode 100644 index 0000000000..06f0c95dc4 --- /dev/null +++ b/test/files/pos/t7226.scala @@ -0,0 +1,26 @@ +trait HK { + type Rep[X] + + // okay + def unzip2[A, B](ps: Rep[List[(A, B)]]) + unzip2(null.asInstanceOf[Rep[List[(Int, String)]]]) + + // okay + def unzipHK[A, B, C[_]](ps: Rep[C[(A, B)]]) + unzipHK(null.asInstanceOf[Rep[List[(Int, String)]]]) + + def unzipHKRet0[A, C[_]](ps: C[A]): C[Int] + def ls: List[String] + unzipHKRet0(ls) + + // fail + def unzipHKRet[A, C[_]](ps: Rep[C[A]]): Rep[C[Int]] + def rls: Rep[List[String]] + unzipHKRet(rls) +} + +trait HK1 { + type Rep[A] + def unzip1[A, B, C[_]](ps: Rep[C[(A, B)]]): (Rep[C[A]], Rep[C[B]]) + def doUnzip1[A, B](ps: Rep[List[(A, B)]]) = unzip1(ps) +} |