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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 /test/files/neg | |
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 'test/files/neg')
-rw-r--r-- | test/files/neg/t8219-any-any-ref-equals.check | 10 | ||||
-rw-r--r-- | test/files/neg/t8219-any-any-ref-equals.scala | 8 |
2 files changed, 18 insertions, 0 deletions
diff --git a/test/files/neg/t8219-any-any-ref-equals.check b/test/files/neg/t8219-any-any-ref-equals.check new file mode 100644 index 0000000000..95d2536fba --- /dev/null +++ b/test/files/neg/t8219-any-any-ref-equals.check @@ -0,0 +1,10 @@ +t8219-any-any-ref-equals.scala:5: error: method ==: (x$1: Any)Boolean does not take type parameters. + "".==[Int] + ^ +t8219-any-any-ref-equals.scala:6: error: method ==: (x$1: Any)Boolean does not take type parameters. + ("": AnyRef).==[Int] + ^ +t8219-any-any-ref-equals.scala:7: error: method ==: (x$1: Any)Boolean does not take type parameters. + ("": Object).==[Int] + ^ +three errors found diff --git a/test/files/neg/t8219-any-any-ref-equals.scala b/test/files/neg/t8219-any-any-ref-equals.scala new file mode 100644 index 0000000000..f1b81fa734 --- /dev/null +++ b/test/files/neg/t8219-any-any-ref-equals.scala @@ -0,0 +1,8 @@ +object Test { + // The error message tells us that AnyRef#== and Any#== are overloaded. + // A real class couldn't define such an overload, why do we allow AnyRef + // to do so? + "".==[Int] + ("": AnyRef).==[Int] + ("": Object).==[Int] +} |