Merge pull request #5402 from som-snytt/issue/8040-unused

SI-8040 Improve unused warnings

1 files changed, 53 insertions, 0 deletions

diff --git a/test/files/neg/warn-unused-patvars.scala b/test/files/neg/warn-unused-patvars.scala
new file mode 100644
index 0000000000..3d35dfedd6
--- /dev/null
+++ b/test/files/neg/warn-unused-patvars.scala
@@ -0,0 +1,53 @@
+
+// verify no warning when -Ywarn-unused:-patvars
+
+case class C(a: Int, b: String, c: Option[String])
+case class D(a: Int)
+
+trait Boundings {
+
+  private val x = 42                      // warn, sanity check
+
+  def c = C(42, "hello", Some("world"))
+  def d = D(42)
+
+  def f() = {
+    val C(x, y, Some(z)) = c              // no warn
+    17
+  }
+  def g() = {
+    val C(x @ _, y @ _, Some(z @ _)) = c  // no warn
+    17
+  }
+  def h() = {
+    val C(x @ _, y @ _, z @ Some(_)) = c  // no warn for z?
+    17
+  }
+
+  def v() = {
+    val D(x) = d                          // warn, fixme
+    17
+  }
+  def w() = {
+    val D(x @ _) = d                      // warn, fixme (valdef pos is different)
+    17
+  }
+
+}
+
+trait Forever {
+  def f = {
+    val t = Option((17, 42))
+    for {
+      ns <- t
+      (i, j) = ns                        // no warn
+    } yield (i + j)
+  }
+  def g = {
+    val t = Option((17, 42))
+    for {
+      ns <- t
+      (i, j) = ns                        // no warn
+    } yield 42
+  }
+}