4 files changed, 58 insertions, 0 deletions
diff --git a/test/files/neg/t7715.check b/test/files/neg/t7715.check
new file mode 100644
index 0000000000..4ee6b6c95d
--- /dev/null
+++ b/test/files/neg/t7715.check
@@ -0,0 +1,13 @@
+t7715.scala:8: error: error in interpolated string: identifier or block expected
+  days map s"On the $_th day of Christmas" foreach println
+                     ^
+t7715.scala:10: error: error in interpolated string: identifier or block expected
+  val rf = (n: Int) => s"\\*{$_}"(n).r
+                              ^
+t7715.scala:17: error: unbound placeholder parameter
+  days zip days map s"${_: Int} by ${_: Int}".tupled foreach println
+                        ^
+t7715.scala:17: error: unbound placeholder parameter
+  days zip days map s"${_: Int} by ${_: Int}".tupled foreach println
+                                     ^
+four errors found
diff --git a/test/files/neg/t7715.scala b/test/files/neg/t7715.scala
new file mode 100644
index 0000000000..637ab8df6d
--- /dev/null
+++ b/test/files/neg/t7715.scala
@@ -0,0 +1,18 @@
+
+import PartialFunction.cond
+import util._
+
+object Test extends App {
+  val days = (1 to 12).toList
+
+  days map s"On the $_th day of Christmas" foreach println
+
+  val rf = (n: Int) => s"\\*{$_}"(n).r
+  def stars(n: Int)(s: String) = {
+    val r = rf(n)
+    cond(s) { case r(_*) => true }
+  }
+  Console println stars(5)("*****")
+
+  days zip days map s"${_: Int} by ${_: Int}".tupled foreach println
+}
diff --git a/test/files/run/t7715.check b/test/files/run/t7715.check
new file mode 100644
index 0000000000..592d7fe2ea
--- /dev/null
+++ b/test/files/run/t7715.check
@@ -0,0 +1,3 @@
+6
+4
+4
diff --git a/test/files/run/t7715.scala b/test/files/run/t7715.scala
new file mode 100644
index 0000000000..0ad3913016
--- /dev/null
+++ b/test/files/run/t7715.scala
@@ -0,0 +1,24 @@
+
+import PartialFunction.cond
+import util._
+
+object Test extends App {
+
+  object I { def unapply(x: String): Option[Int] = Try(x.toInt).toOption }
+  implicit class RX(val sc: StringContext) {
+    def rx = sc.parts.mkString("(.+)").r
+  }
+
+  Console println ("2 by 4" match {
+    case rx"${I(a)} by ${I(b)}" => a+b
+    case _                      => -1
+  })
+  Console println ("2 by 4" match {
+    case rx"${_} by ${I(b)}"    => b    // pattern placeholder
+    case _                      => -1
+  })
+  Console println ("2 by 4" match {
+    case rx"$_ by ${I(b)}"      => b    // is permitted this way, too
+    case _                      => -1
+  })
+}