Suppress -Wctad-maybe-unsupported on types w/o deduction guides.

There are a handful of standard library types that are intended
to support CTAD but don't need any explicit deduction guides to
do so.

This patch adds a dummy deduction guide to those types to suppress
-Wctad-maybe-unsupported (which gets emitted in user code).

llvm-svn: 367770

1 files changed, 41 insertions, 0 deletions

diff --git a/libcxx/test/std/iterators/predef.iterators/insert.iterators/back.insert.iterator/implicit_ctad.pass.cpp b/libcxx/test/std/iterators/predef.iterators/insert.iterators/back.insert.iterator/implicit_ctad.pass.cpp
new file mode 100644
index 00000000000..7c4ba6a6c29
--- /dev/null
+++ b/libcxx/test/std/iterators/predef.iterators/insert.iterators/back.insert.iterator/implicit_ctad.pass.cpp
@@ -0,0 +1,41 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <iterator>
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// UNSUPPORTED: libcpp-no-deduction-guides
+
+// class back_insert_iterator.
+
+#include <string>
+#include <iterator>
+#include <vector>
+#include <cassert>
+#include <cstddef>
+#include <functional>
+
+#include "test_macros.h"
+
+int main(int, char**)
+{
+    {
+      std::string s;
+      std::back_insert_iterator bs(s);
+      ASSERT_SAME_TYPE(decltype(bs), std::back_insert_iterator<std::string>);
+    }
+  {
+    std::vector<int> v;
+    std::back_insert_iterator bv(v);
+    std::back_insert_iterator cp(bv);
+    ASSERT_SAME_TYPE(decltype(bv), std::back_insert_iterator<std::vector<int>>);
+    ASSERT_SAME_TYPE(decltype(cp), std::back_insert_iterator<std::vector<int>>);
+  }
+
+  return 0;
+}