1 files changed, 50 insertions, 0 deletions
diff --git a/third_party/fuchsia/repo/sdk/lib/stdcompat/include/lib/stdcompat/functional.h b/third_party/fuchsia/repo/sdk/lib/stdcompat/include/lib/stdcompat/functional.h
new file mode 100644
index 000000000..34d44e0d5
--- /dev/null
+++ b/third_party/fuchsia/repo/sdk/lib/stdcompat/include/lib/stdcompat/functional.h
@@ -0,0 +1,50 @@
+// Copyright 2021 The Fuchsia Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef LIB_STDCOMPAT_INCLUDE_LIB_STDCOMPAT_FUNCTIONAL_H_
+#define LIB_STDCOMPAT_INCLUDE_LIB_STDCOMPAT_FUNCTIONAL_H_
+
+#include "internal/functional.h"
+
+namespace cpp20 {
+
+// This version is always constexpr-qualified, with no other changes from C++17.
+
+#if defined(__cpp_lib_invoke) && defined(__cpp_lib_constexpr_functional) &&     \
+    __cpp_lib_invoke >= 201411L && __cpp_lib_constexpr_functional >= 201907L && \
+    !defined(LIB_STDCOMPAT_USE_POLYFILLS)
+
+using std::invoke;
+
+#else  // Provide invoke() polyfill
+
+template <typename F, typename... Args>
+constexpr cpp17::invoke_result_t<F, Args...> invoke(F&& f, Args&&... args) noexcept(
+    cpp17::is_nothrow_invocable_v<F, Args...>) {
+  return ::cpp17::internal::invoke(std::forward<F>(f), std::forward<Args>(args)...);
+}
+
+#endif  // __cpp_lib_invoke >= 201411L && __cpp_lib_constexpr_functional >= 201907L &&
+        // !defined(LIB_STDCOMPAT_USE_POLYFILLS)
+
+#if defined(__cpp_lib_bind_front) && __cpp_lib_bind_front >= 201907L && \
+    !defined(LIB_STDCOMPAT_USE_POLYFILLS)
+
+using std::bind_front;
+
+#else  // Provide bind_front() polyfill
+
+template <typename F, typename... Args>
+constexpr ::cpp20::internal::front_binder_t<F, Args...> bind_front(F&& f, Args&&... args) noexcept(
+    cpp17::is_nothrow_constructible_v<::cpp20::internal::front_binder_t<F, Args...>,
+                                      cpp17::in_place_t, F, Args...>) {
+  return ::cpp20::internal::front_binder_t<F, Args...>(cpp17::in_place, std::forward<F>(f),
+                                                       std::forward<Args>(args)...);
+}
+
+#endif  // __cpp_lib_bind_front >= 201907L && !defined(LIB_STDCOMPAT_USE_POLYFILLS)
+
+}  // namespace cpp20
+
+#endif  // LIB_STDCOMPAT_INCLUDE_LIB_STDCOMPAT_FUNCTIONAL_H_