1 files changed, 21 insertions, 0 deletions
diff --git a/gcc/testsuite/g++.dg/template/ttp28.C b/gcc/testsuite/g++.dg/template/ttp28.C
new file mode 100644
index 0000000000..a15dea1e7f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/ttp28.C
@@ -0,0 +1,21 @@
+// PR c++/56971
+
+template <typename T>
+class rp {
+};
+
+template <template <typename> class P>
+struct b {
+    template <class, template <typename> class FriendP>
+    friend void f(b<FriendP> from);
+};
+
+template <class, template <typename> class P>
+void f(b<P> from) {
+}
+
+int main() {
+    b<rp> v;
+    f<int>(v);
+    return 0;
+}