Files
react-native/ReactCommon/butter/function.h
T
Christoph Purrer 6c315de226 Add butter/function.h (#35385)
Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/35385

In OpenSource builds folly:: types are not always easy to consume.

With butter:: we actually allow consumers to opt-into other/non folly:: types (by providing a custom butter:: implementation).

This change adds a butter::function for that purpose.

It is especially useful for react-native-windows which prefers Mso::Functor over folly::Function.

You can use it by setting those compiler flags:
-DBUTTER_FUNCTION_OVERRIDE_INCLUDE=<functional/functor.h>
-DBUTTER_FUNCTION_OVERRIDE=Mso::Functor

std::function is no option as it is not move-only and we can't wait till 2025 > https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p0288r9.html

Changelog: [Internal]

Reviewed By: sammy-SC

Differential Revision: D41388193

fbshipit-source-id: 56f58b9ddc602aa4b13000031d50de5228b4a16b
2022-11-21 11:17:01 -08:00

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1.0 KiB
C++

/*
* 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