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author | Adriaan Moors <adriaan.moors@epfl.ch> | 2010-08-20 14:48:12 +0000 |
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committer | Adriaan Moors <adriaan.moors@epfl.ch> | 2010-08-20 14:48:12 +0000 |
commit | e11cac6ecc3c8791be3a37fc3b9f6837c9d46d23 (patch) | |
tree | dfa0ddc52703125288c6d7a85c4dc7befdb1508c /test/files/neg/t2462b.scala | |
parent | d4645f93728ee8cb40a17c23f92a272e27052889 (diff) | |
download | scala-e11cac6ecc3c8791be3a37fc3b9f6837c9d46d23.tar.gz scala-e11cac6ecc3c8791be3a37fc3b9f6837c9d46d23.tar.bz2 scala-e11cac6ecc3c8791be3a37fc3b9f6837c9d46d23.zip |
closes 2462. better implicit error messages.
@implicitNotFound(msg="Custom error message that may refer to type parameters ${T} and ${U}")
trait Constraint[T, U]
whenever an implicit argument of type Constraint[A, B] cannot be found,
the custom error message will be used, where the type arguments are
interpolated in the obvious way
note: if the msg in the annotation references non-existing type params,
a warning is emitted
the patch also cleans up annotation argument retrieval (moved it to
AnnotationInfo from Symbol)
review by odersky
Diffstat (limited to 'test/files/neg/t2462b.scala')
-rw-r--r-- | test/files/neg/t2462b.scala | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/test/files/neg/t2462b.scala b/test/files/neg/t2462b.scala new file mode 100644 index 0000000000..7a1389cc8e --- /dev/null +++ b/test/files/neg/t2462b.scala @@ -0,0 +1,12 @@ +package test + +import scala.annotation.implicitNotFound + +@implicitNotFound(msg = "Cannot construct a collection of type ${Too} with elements of type ${Elem} based on a collection of type ${From}.") +trait Meh[-From, +To] + +@implicitNotFound(msg = "Cannot construct a collection of type ${To} ${Elem}.") +trait Meh2[-From, +To] + +class thankyoupartest { def x = 42 } +class testmustfail extends thankyoupartest { def x = 43 } |