1 files changed, 20 insertions, 0 deletions
diff --git a/gcc/testsuite/g++.dg/expr/unary2.C b/gcc/testsuite/g++.dg/expr/unary2.C
new file mode 100644
index 00000000000..9d6acc84488
--- /dev/null
+++ b/gcc/testsuite/g++.dg/expr/unary2.C
@@ -0,0 +1,20 @@
+// { dg-do compile }
+// Unary plus/minus are not lvalues.
+
+// In templates we require an instantiation to emit the diagnostic. This
+//  is wrong and it is PR 18474.
+
+int n;
+
+void f(void)
+{
+  -n = 0;        // { dg-error "non-lvalue" }
+  +n = 0;        // { dg-error "non-lvalue" }
+}
+
+template <int>
+void g(void)
+{
+  -n = 0;        // { dg-error "non-lvalue" "" { xfail *-*-* } }
+  +n = 0;        // { dg-error "non-lvalue" "" { xfail *-*-* } }
+}