1 files changed, 39 insertions, 0 deletions
diff --git a/gcc/testsuite/gdc.test/fail_compilation/fail20730a.d b/gcc/testsuite/gdc.test/fail_compilation/fail20730a.d
new file mode 100644
index 00000000000..dcf8960c62c
--- /dev/null
+++ b/gcc/testsuite/gdc.test/fail_compilation/fail20730a.d
@@ -0,0 +1,39 @@
+/*
+REQUIRED_ARGS: -o-
+TEST_OUTPUT:
+---
+fail_compilation/fail20730a.d(11): Error: undefined identifier `undef20730`
+---
+*/
+void test20730()
+{
+    auto f = File().byLine;
+    undef20730();
+}
+
+struct File
+{
+    shared uint refs;
+
+    this(this)
+    {
+        atomicOp!"+="(refs, 1);
+    }
+
+    struct ByLineImpl(Char)
+    {
+        File file;
+        char[] line;
+    }
+
+    auto byLine()
+    {
+        return ByLineImpl!char();
+    }
+}
+
+T atomicOp(string op, T, V1)(ref shared T val, V1 mod)
+    if (__traits(compiles, mixin("*cast(T*)&val" ~ op ~ "mod")))
+{
+    return val;
+}