1 files changed, 102 insertions, 0 deletions
diff --git a/contrib/llvm-project/libcxx/include/__functional/reference_wrapper.h b/contrib/llvm-project/libcxx/include/__functional/reference_wrapper.h
new file mode 100644
index 000000000000..54de06a8879c
--- /dev/null
+++ b/contrib/llvm-project/libcxx/include/__functional/reference_wrapper.h
@@ -0,0 +1,102 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___FUNCTIONAL_REFERENCE_WRAPPER_H
+#define _LIBCPP___FUNCTIONAL_REFERENCE_WRAPPER_H
+
+#include <__config>
+#include <__functional/invoke.h>
+#include <__functional/weak_result_type.h>
+#include <__memory/addressof.h>
+#include <__type_traits/enable_if.h>
+#include <__type_traits/remove_cvref.h>
+#include <__utility/declval.h>
+#include <__utility/forward.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp>
+class _LIBCPP_TEMPLATE_VIS reference_wrapper : public __weak_result_type<_Tp> {
+public:
+  // types
+  typedef _Tp type;
+
+private:
+  type* __f_;
+
+  static void __fun(_Tp&) _NOEXCEPT;
+  static void __fun(_Tp&&) = delete;
+
+public:
+  template <
+      class _Up,
+      class = __enable_if_t<!__is_same_uncvref<_Up, reference_wrapper>::value, decltype(__fun(std::declval<_Up>())) > >
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference_wrapper(_Up&& __u)
+      _NOEXCEPT_(noexcept(__fun(std::declval<_Up>()))) {
+    type& __f = static_cast<_Up&&>(__u);
+    __f_      = std::addressof(__f);
+  }
+
+  // access
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 operator type&() const _NOEXCEPT { return *__f_; }
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 type& get() const _NOEXCEPT { return *__f_; }
+
+  // invoke
+  template <class... _ArgTypes>
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 typename __invoke_of<type&, _ArgTypes...>::type
+  operator()(_ArgTypes&&... __args) const
+#if _LIBCPP_STD_VER >= 17
+      // Since is_nothrow_invocable requires C++17 LWG3764 is not backported
+      // to earlier versions.
+      noexcept(is_nothrow_invocable_v<_Tp&, _ArgTypes...>)
+#endif
+  {
+    return std::__invoke(get(), std::forward<_ArgTypes>(__args)...);
+  }
+};
+
+#if _LIBCPP_STD_VER >= 17
+template <class _Tp>
+reference_wrapper(_Tp&) -> reference_wrapper<_Tp>;
+#endif
+
+template <class _Tp>
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference_wrapper<_Tp> ref(_Tp& __t) _NOEXCEPT {
+  return reference_wrapper<_Tp>(__t);
+}
+
+template <class _Tp>
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference_wrapper<_Tp>
+ref(reference_wrapper<_Tp> __t) _NOEXCEPT {
+  return __t;
+}
+
+template <class _Tp>
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference_wrapper<const _Tp> cref(const _Tp& __t) _NOEXCEPT {
+  return reference_wrapper<const _Tp>(__t);
+}
+
+template <class _Tp>
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference_wrapper<const _Tp>
+cref(reference_wrapper<_Tp> __t) _NOEXCEPT {
+  return __t;
+}
+
+template <class _Tp>
+void ref(const _Tp&&) = delete;
+template <class _Tp>
+void cref(const _Tp&&) = delete;
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___FUNCTIONAL_REFERENCE_WRAPPER_H