1 files changed, 39 insertions, 0 deletions
diff --git a/pw_minimal_cpp_stdlib/public/pw_minimal_cpp_stdlib/internal/functional.h b/pw_minimal_cpp_stdlib/public/pw_minimal_cpp_stdlib/internal/functional.h
new file mode 100644
index 000000000..1f55a6736
--- /dev/null
+++ b/pw_minimal_cpp_stdlib/public/pw_minimal_cpp_stdlib/internal/functional.h
@@ -0,0 +1,39 @@
+// Copyright 2023 The Pigweed Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may not
+// use this file except in compliance with the License. You may obtain a copy of
+// the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations under
+// the License.
+#pragma once
+
+#include "pw_polyfill/standard_library/namespace.h"
+
+_PW_POLYFILL_BEGIN_NAMESPACE_STD
+
+template <typename T>
+class reference_wrapper {
+ public:
+  using type = T;
+
+  // This constructor is incomplete / incorrect!
+  constexpr reference_wrapper(T& reference) : pointer_(&reference) {}
+
+  constexpr reference_wrapper(const reference_wrapper&) noexcept = default;
+  constexpr reference_wrapper& operator=(const reference_wrapper&) noexcept =
+      default;
+
+  constexpr T& get() const noexcept { return *pointer_; }
+  constexpr operator T&() const noexcept { return *pointer_; }
+
+ private:
+  T* pointer_;
+};
+
+_PW_POLYFILL_END_NAMESPACE_STD