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author | Jason Zaugg <jzaugg@gmail.com> | 2014-02-04 15:55:59 +0100 |
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committer | Adriaan Moors <adriaan.moors@typesafe.com> | 2014-02-10 10:58:58 -0800 |
commit | 4a8edc03653cb0f6b6ed1cdea1779a19df20f8f5 (patch) | |
tree | a2504af682ddcd74d8050bbf26639b5c58b7c636 /src/library-aux | |
parent | b0f81ed35a45fffb9d0761299013d9d5f324ade6 (diff) | |
download | scala-4a8edc03653cb0f6b6ed1cdea1779a19df20f8f5.tar.gz scala-4a8edc03653cb0f6b6ed1cdea1779a19df20f8f5.tar.bz2 scala-4a8edc03653cb0f6b6ed1cdea1779a19df20f8f5.zip |
SI-8129 Make Object#== override Any#==
And the same for !=
If we tried to declare these signatures in non-fictional classes,
we would be chastised about collapsing into the "same signature after
erasure".
This will have an influence of typing, as the typechecking of
arguments is sensitive to overloading: if multiple variants are
feasible, the argument will be typechecked with a wildcard expected
type. So people inspecting the types of the arguments to `==` before
this change might have seen an interesting type for
`if (true) x else y`, but now the `If` will have type `Any`, as we
don't need to calculate the LUB.
I've left a TODO to note that we should really make `Any#{==, !=}`
non-final and include a final override in `AnyVal`. But I don't think
that is particularly urgent.
Diffstat (limited to 'src/library-aux')
-rw-r--r-- | src/library-aux/scala/AnyRef.scala | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/src/library-aux/scala/AnyRef.scala b/src/library-aux/scala/AnyRef.scala index 362fbcf0f5..8c1862e729 100644 --- a/src/library-aux/scala/AnyRef.scala +++ b/src/library-aux/scala/AnyRef.scala @@ -76,8 +76,8 @@ trait AnyRef extends Any { * @param arg0 the object to compare against this object for equality. * @return `true` if the receiver object is equivalent to the argument; `false` otherwise. */ - final def ==(that: AnyRef): Boolean = - if (this eq null) that eq null + final def ==(that: Any): Boolean = + if (this eq null) that.asInstanceOf[AnyRef] eq null else this equals that /** Create a copy of the receiver object. |