From 4d85e112a33518f64f7d76c904884ba5abc2587b Mon Sep 17 00:00:00 2001
From: Samuel Susla <samuelsusla@meta.com>
Date: Tue, 22 Aug 2023 06:35:14 -0700
Subject: [PATCH] Delete use of folly::function (#39093)

Summary:
Changelog: [internal]

Pull Request resolved: https://github.com/facebook/react-native/pull/39093

I was looking at Folly containers and found we were using folly::function. According to the compiler, we don't need it. It should fail during build time if its properties were needed.
Documentation for folly function: https://github.com/facebook/folly/blob/main/folly/docs/Function.md

Reviewed By: christophpurrer

Differential Revision: D48519164

fbshipit-source-id: 88002ca3a1302db2a397fc7f5e3cae354669a9ff
---
 .../ReactCommon/butter/function.h             | 51 -------------------
 .../ReactCommon/react/bridging/Base.h         |  5 +-
 .../ReactCommon/react/bridging/Function.h     | 17 +++----
 .../android/ReactCommon/JavaTurboModule.cpp   |  1 -
 4 files changed, 9 insertions(+), 65 deletions(-)
 delete mode 100644 packages/react-native/ReactCommon/butter/function.h

diff --git a/packages/react-native/ReactCommon/butter/function.h b/packages/react-native/ReactCommon/butter/function.h
deleted file mode 100644
index 724752498f8..00000000000
--- a/packages/react-native/ReactCommon/butter/function.h
+++ /dev/null
@@ -1,51 +0,0 @@
-/*
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-#pragma once
-
-#include <butter/butter.h>
-
-#if (                                            \
-    defined(BUTTER_FUNCTION_OVERRIDE_INCLUDE) && \
-    defined(BUTTER_FUNCTION_OVERRIDE))
-
-#include BUTTER_FUNCTION_OVERRIDE_INCLUDE
-
-#elif defined(BUTTER_USE_FOLLY_CONTAINERS)
-
-#include <folly/Function.h>
-
-#else
-
-#include <functional>
-
-#endif
-
-namespace facebook {
-namespace butter {
-
-#if (                                            \
-    defined(BUTTER_FUNCTION_OVERRIDE_INCLUDE) && \
-    defined(BUTTER_FUNCTION_OVERRIDE))
-
-template <typename... Ts>
-using function = BUTTER_FUNCTION_OVERRIDE<Ts...>;
-
-#elif defined(BUTTER_USE_FOLLY_CONTAINERS)
-
-template <typename... Ts>
-using function = folly::Function<Ts...>;
-
-#else
-
-template <typename... Ts>
-using function = std::function<Ts...>;
-
-#endif
-
-} // namespace butter
-} // namespace facebook
diff --git a/packages/react-native/ReactCommon/react/bridging/Base.h b/packages/react-native/ReactCommon/react/bridging/Base.h
index 4ff8ef3a8e4..0de8aa19e7b 100644
--- a/packages/react-native/ReactCommon/react/bridging/Base.h
+++ b/packages/react-native/ReactCommon/react/bridging/Base.h
@@ -10,7 +10,6 @@
 #include <react/bridging/Convert.h>
 
 #include <ReactCommon/CallInvoker.h>
-#include <butter/function.h>
 #include <jsi/jsi.h>
 
 #include <cstdint>
@@ -36,12 +35,12 @@ struct function_wrapper;
 
 template <typename C, typename R, typename... Args>
 struct function_wrapper<R (C::*)(Args...)> {
-  using type = butter::function<R(Args...)>;
+  using type = std::function<R(Args...)>;
 };
 
 template <typename C, typename R, typename... Args>
 struct function_wrapper<R (C::*)(Args...) const> {
-  using type = butter::function<R(Args...)>;
+  using type = std::function<R(Args...)>;
 };
 
 template <typename T, typename = void>
diff --git a/packages/react-native/ReactCommon/react/bridging/Function.h b/packages/react-native/ReactCommon/react/bridging/Function.h
index 568dd59acba..b1ba9520313 100644
--- a/packages/react-native/ReactCommon/react/bridging/Function.h
+++ b/packages/react-native/ReactCommon/react/bridging/Function.h
@@ -12,8 +12,6 @@
 
 #include <ReactCommon/SchedulerPriority.h>
 
-#include <butter/function.h>
-
 namespace facebook::react {
 
 template <typename F>
@@ -169,8 +167,8 @@ struct Bridging<SyncCallback<R(Args...)>> {
 };
 
 template <typename R, typename... Args>
-struct Bridging<butter::function<R(Args...)>> {
-  using Func = butter::function<R(Args...)>;
+struct Bridging<std::function<R(Args...)>> {
+  using Func = std::function<R(Args...)>;
   using IndexSequence = std::index_sequence_for<Args...>;
 
   static constexpr size_t kArgumentCount = sizeof...(Args);
@@ -219,15 +217,14 @@ struct Bridging<butter::function<R(Args...)>> {
 template <typename R, typename... Args>
 struct Bridging<
     std::function<R(Args...)>,
-    std::enable_if_t<!std::is_same_v<
-        std::function<R(Args...)>,
-        butter::function<R(Args...)>>>>
-    : Bridging<butter::function<R(Args...)>> {};
+    std::enable_if_t<
+        !std::is_same_v<std::function<R(Args...)>, std::function<R(Args...)>>>>
+    : Bridging<std::function<R(Args...)>> {};
 
 template <typename R, typename... Args>
-struct Bridging<R(Args...)> : Bridging<butter::function<R(Args...)>> {};
+struct Bridging<R(Args...)> : Bridging<std::function<R(Args...)>> {};
 
 template <typename R, typename... Args>
-struct Bridging<R (*)(Args...)> : Bridging<butter::function<R(Args...)>> {};
+struct Bridging<R (*)(Args...)> : Bridging<std::function<R(Args...)>> {};
 
 } // namespace facebook::react
diff --git a/packages/react-native/ReactCommon/react/nativemodule/core/platform/android/ReactCommon/JavaTurboModule.cpp b/packages/react-native/ReactCommon/react/nativemodule/core/platform/android/ReactCommon/JavaTurboModule.cpp
index 0940a6ea48a..138e1d817ab 100644
--- a/packages/react-native/ReactCommon/react/nativemodule/core/platform/android/ReactCommon/JavaTurboModule.cpp
+++ b/packages/react-native/ReactCommon/react/nativemodule/core/platform/android/ReactCommon/JavaTurboModule.cpp
@@ -16,7 +16,6 @@
 #include <ReactCommon/TurboModule.h>
 #include <ReactCommon/TurboModulePerfLogger.h>
 #include <ReactCommon/TurboModuleUtils.h>
-#include <butter/function.h>
 #include <jsi/JSIDynamic.h>
 #include <react/debug/react_native_assert.h>
 #include <react/jni/NativeMap.h>