verdnatura-chat/ios/Pods/Flipper-Folly/folly/functional/ApplyTuple.h

232 lines
7.1 KiB
C
Raw Normal View History

/*
* Copyright (c) Facebook, Inc. and its affiliates.
*
* 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
*
* http://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 <functional>
#include <tuple>
#include <utility>
#include <folly/Traits.h>
#include <folly/Utility.h>
#include <folly/functional/Invoke.h>
namespace folly {
//////////////////////////////////////////////////////////////////////
/**
* Helper to generate an index sequence from a tuple like type
*/
template <typename Tuple>
using index_sequence_for_tuple =
std::make_index_sequence<std::tuple_size<Tuple>::value>;
namespace detail {
namespace apply_tuple {
namespace adl {
using std::get;
struct ApplyInvoke {
template <typename T>
using seq = index_sequence_for_tuple<std::remove_reference_t<T>>;
template <typename F, typename T, std::size_t... I>
static constexpr auto
invoke_(F&& f, T&& t, std::index_sequence<I...>) noexcept(
is_nothrow_invocable<F&&, decltype(get<I>(std::declval<T>()))...>::value)
-> invoke_result_t<F&&, decltype(get<I>(std::declval<T>()))...> {
return invoke(static_cast<F&&>(f), get<I>(static_cast<T&&>(t))...);
}
};
template <
typename Tuple,
std::size_t... Indices,
typename ReturnTuple =
std::tuple<decltype(get<Indices>(std::declval<Tuple>()))...>>
auto forward_tuple(Tuple&& tuple, std::index_sequence<Indices...>)
-> ReturnTuple {
return ReturnTuple{get<Indices>(std::forward<Tuple>(tuple))...};
}
} // namespace adl
} // namespace apply_tuple
} // namespace detail
struct ApplyInvoke : private detail::apply_tuple::adl::ApplyInvoke {
public:
template <typename F, typename T>
constexpr auto operator()(F&& f, T&& t) const noexcept(
noexcept(invoke_(static_cast<F&&>(f), static_cast<T&&>(t), seq<T>{})))
-> decltype(invoke_(static_cast<F&&>(f), static_cast<T&&>(t), seq<T>{})) {
return invoke_(static_cast<F&&>(f), static_cast<T&&>(t), seq<T>{});
}
};
//////////////////////////////////////////////////////////////////////
// libc++ v3.9 has std::apply
// android ndk r15c libc++ claims to be v3.9 but is missing std::apply
#if __cpp_lib_apply >= 201603 || \
(((__ANDROID__ && _LIBCPP_VERSION > 3900) || \
(!__ANDROID__ && _LIBCPP_VERSION > 3800)) && \
_LIBCPP_STD_VER > 14) || \
(_MSC_VER && _HAS_CXX17)
/* using override */ using std::apply;
#else // __cpp_lib_apply >= 201603
// mimic: std::apply, C++17
template <typename F, typename Tuple>
constexpr decltype(auto) apply(F&& func, Tuple&& tuple) {
return ApplyInvoke{}(static_cast<F&&>(func), static_cast<Tuple&&>(tuple));
}
#endif // __cpp_lib_apply >= 201603
/**
* Get a tuple of references from the passed tuple, forwarding will be applied
* on the individual types of the tuple based on the value category of the
* passed tuple
*
* For example
*
* forward_tuple(std::make_tuple(1, 2))
*
* Returns a std::tuple<int&&, int&&>,
*
* auto tuple = std::make_tuple(1, 2);
* forward_tuple(tuple)
*
* Returns a std::tuple<int&, int&>
*/
template <typename Tuple>
auto forward_tuple(Tuple&& tuple) noexcept
-> decltype(detail::apply_tuple::adl::forward_tuple(
std::declval<Tuple>(),
std::declval<
index_sequence_for_tuple<std::remove_reference_t<Tuple>>>())) {
return detail::apply_tuple::adl::forward_tuple(
std::forward<Tuple>(tuple),
index_sequence_for_tuple<std::remove_reference_t<Tuple>>{});
}
/**
* Mimic the invoke suite of traits for tuple based apply invocation
*/
template <typename F, typename Tuple>
struct apply_result : invoke_result<ApplyInvoke, F, Tuple> {};
template <typename F, typename Tuple>
using apply_result_t = invoke_result_t<ApplyInvoke, F, Tuple>;
template <typename F, typename Tuple>
struct is_applicable : is_invocable<ApplyInvoke, F, Tuple> {};
template <typename F, typename Tuple>
FOLLY_INLINE_VARIABLE constexpr bool is_applicable_v =
is_applicable<F, Tuple>::value;
template <typename R, typename F, typename Tuple>
struct is_applicable_r : is_invocable_r<R, ApplyInvoke, F, Tuple> {};
template <typename R, typename F, typename Tuple>
FOLLY_INLINE_VARIABLE constexpr bool is_applicable_r_v =
is_applicable_r<R, F, Tuple>::value;
template <typename F, typename Tuple>
struct is_nothrow_applicable : is_nothrow_invocable<ApplyInvoke, F, Tuple> {};
template <typename F, typename Tuple>
FOLLY_INLINE_VARIABLE constexpr bool is_nothrow_applicable_v =
is_nothrow_applicable<F, Tuple>::value;
template <typename R, typename F, typename Tuple>
struct is_nothrow_applicable_r
: is_nothrow_invocable_r<R, ApplyInvoke, F, Tuple> {};
template <typename R, typename F, typename Tuple>
FOLLY_INLINE_VARIABLE constexpr bool is_nothrow_applicable_r_v =
is_nothrow_applicable_r<R, F, Tuple>::value;
namespace detail {
namespace apply_tuple {
template <class F>
class Uncurry {
public:
explicit Uncurry(F&& func) : func_(std::move(func)) {}
explicit Uncurry(const F& func) : func_(func) {}
template <class Tuple>
auto operator()(Tuple&& tuple) const
-> decltype(apply(std::declval<F>(), std::forward<Tuple>(tuple))) {
return apply(func_, std::forward<Tuple>(tuple));
}
private:
F func_;
};
} // namespace apply_tuple
} // namespace detail
/**
* Wraps a function taking N arguments into a function which accepts a tuple of
* N arguments. Note: This function will also accept an std::pair if N == 2.
*
* For example, given the below code:
*
* std::vector<std::tuple<int, int, int>> rows = ...;
* auto test = [](std::tuple<int, int, int>& row) {
* return std::get<0>(row) * std::get<1>(row) * std::get<2>(row) == 24;
* };
* auto found = std::find_if(rows.begin(), rows.end(), test);
*
*
* 'test' could be rewritten as:
*
* auto test =
* folly::uncurry([](int a, int b, int c) { return a * b * c == 24; });
*
*/
template <class F>
auto uncurry(F&& f)
-> detail::apply_tuple::Uncurry<typename std::decay<F>::type> {
return detail::apply_tuple::Uncurry<typename std::decay<F>::type>(
std::forward<F>(f));
}
#if __cpp_lib_make_from_tuple || (_MSC_VER >= 1910 && _MSVC_LANG > 201402)
/* using override */ using std::make_from_tuple;
#else
namespace detail {
namespace apply_tuple {
template <class T>
struct Construct {
template <class... Args>
constexpr T operator()(Args&&... args) const {
return T(std::forward<Args>(args)...);
}
};
} // namespace apply_tuple
} // namespace detail
// mimic: std::make_from_tuple, C++17
template <class T, class Tuple>
constexpr T make_from_tuple(Tuple&& t) {
return apply(detail::apply_tuple::Construct<T>(), std::forward<Tuple>(t));
}
#endif
//////////////////////////////////////////////////////////////////////
} // namespace folly