c++: Add testcase for DR 2874

Seems we already allow the partial specializations the way the DR clarifies,
so this patch just adds a testcase which verifies that.

2024-09-25  Jakub Jelinek  <jakub@redhat.com>

	* g++.dg/DRs/dr2874.C: New test.

diff --git a/gcc/testsuite/g++.dg/DRs/dr2874.C b/gcc/testsuite/g++.dg/DRs/dr2874.C
new file mode 100644 (file)
index 0000000..1098129
--- /dev/null
+++ b/gcc/testsuite/g++.dg/DRs/dr2874.C
@@ -0,0 +1,13 @@
+// DR 2874 - Qualified declarations of partial specializations
+// { dg-do compile { target c++11 } }
+
+namespace N {
+  template <typename T>
+  struct A;
+}
+
+template <>
+struct N::A <int>;
+
+template <typename T>
+struct N::A <T *>;