diff options
Diffstat (limited to 'third_party/abseil_cpp/absl/utility/utility.h')
| -rw-r--r-- | third_party/abseil_cpp/absl/utility/utility.h | 350 |
1 files changed, 0 insertions, 350 deletions
diff --git a/third_party/abseil_cpp/absl/utility/utility.h b/third_party/abseil_cpp/absl/utility/utility.h deleted file mode 100644 index bf9232209a9b..000000000000 --- a/third_party/abseil_cpp/absl/utility/utility.h +++ /dev/null @@ -1,350 +0,0 @@ -// Copyright 2017 The Abseil Authors. -// -// 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 -// -// https://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. -// -// This header file contains C++11 versions of standard <utility> header -// abstractions available within C++14 and C++17, and are designed to be drop-in -// replacement for code compliant with C++14 and C++17. -// -// The following abstractions are defined: -// -// * integer_sequence<T, Ints...> == std::integer_sequence<T, Ints...> -// * index_sequence<Ints...> == std::index_sequence<Ints...> -// * make_integer_sequence<T, N> == std::make_integer_sequence<T, N> -// * make_index_sequence<N> == std::make_index_sequence<N> -// * index_sequence_for<Ts...> == std::index_sequence_for<Ts...> -// * apply<Functor, Tuple> == std::apply<Functor, Tuple> -// * exchange<T> == std::exchange<T> -// * make_from_tuple<T> == std::make_from_tuple<T> -// -// This header file also provides the tag types `in_place_t`, `in_place_type_t`, -// and `in_place_index_t`, as well as the constant `in_place`, and -// `constexpr` `std::move()` and `std::forward()` implementations in C++11. -// -// References: -// -// https://en.cppreference.com/w/cpp/utility/integer_sequence -// https://en.cppreference.com/w/cpp/utility/apply -// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2013/n3658.html - -#ifndef ABSL_UTILITY_UTILITY_H_ -#define ABSL_UTILITY_UTILITY_H_ - -#include <cstddef> -#include <cstdlib> -#include <tuple> -#include <utility> - -#include "absl/base/config.h" -#include "absl/base/internal/inline_variable.h" -#include "absl/base/internal/invoke.h" -#include "absl/meta/type_traits.h" - -namespace absl { -ABSL_NAMESPACE_BEGIN - -// integer_sequence -// -// Class template representing a compile-time integer sequence. An instantiation -// of `integer_sequence<T, Ints...>` has a sequence of integers encoded in its -// type through its template arguments (which is a common need when -// working with C++11 variadic templates). `absl::integer_sequence` is designed -// to be a drop-in replacement for C++14's `std::integer_sequence`. -// -// Example: -// -// template< class T, T... Ints > -// void user_function(integer_sequence<T, Ints...>); -// -// int main() -// { -// // user_function's `T` will be deduced to `int` and `Ints...` -// // will be deduced to `0, 1, 2, 3, 4`. -// user_function(make_integer_sequence<int, 5>()); -// } -template <typename T, T... Ints> -struct integer_sequence { - using value_type = T; - static constexpr size_t size() noexcept { return sizeof...(Ints); } -}; - -// index_sequence -// -// A helper template for an `integer_sequence` of `size_t`, -// `absl::index_sequence` is designed to be a drop-in replacement for C++14's -// `std::index_sequence`. -template <size_t... Ints> -using index_sequence = integer_sequence<size_t, Ints...>; - -namespace utility_internal { - -template <typename Seq, size_t SeqSize, size_t Rem> -struct Extend; - -// Note that SeqSize == sizeof...(Ints). It's passed explicitly for efficiency. -template <typename T, T... Ints, size_t SeqSize> -struct Extend<integer_sequence<T, Ints...>, SeqSize, 0> { - using type = integer_sequence<T, Ints..., (Ints + SeqSize)...>; -}; - -template <typename T, T... Ints, size_t SeqSize> -struct Extend<integer_sequence<T, Ints...>, SeqSize, 1> { - using type = integer_sequence<T, Ints..., (Ints + SeqSize)..., 2 * SeqSize>; -}; - -// Recursion helper for 'make_integer_sequence<T, N>'. -// 'Gen<T, N>::type' is an alias for 'integer_sequence<T, 0, 1, ... N-1>'. -template <typename T, size_t N> -struct Gen { - using type = - typename Extend<typename Gen<T, N / 2>::type, N / 2, N % 2>::type; -}; - -template <typename T> -struct Gen<T, 0> { - using type = integer_sequence<T>; -}; - -template <typename T> -struct InPlaceTypeTag { - explicit InPlaceTypeTag() = delete; - InPlaceTypeTag(const InPlaceTypeTag&) = delete; - InPlaceTypeTag& operator=(const InPlaceTypeTag&) = delete; -}; - -template <size_t I> -struct InPlaceIndexTag { - explicit InPlaceIndexTag() = delete; - InPlaceIndexTag(const InPlaceIndexTag&) = delete; - InPlaceIndexTag& operator=(const InPlaceIndexTag&) = delete; -}; - -} // namespace utility_internal - -// Compile-time sequences of integers - -// make_integer_sequence -// -// This template alias is equivalent to -// `integer_sequence<int, 0, 1, ..., N-1>`, and is designed to be a drop-in -// replacement for C++14's `std::make_integer_sequence`. -template <typename T, T N> -using make_integer_sequence = typename utility_internal::Gen<T, N>::type; - -// make_index_sequence -// -// This template alias is equivalent to `index_sequence<0, 1, ..., N-1>`, -// and is designed to be a drop-in replacement for C++14's -// `std::make_index_sequence`. -template <size_t N> -using make_index_sequence = make_integer_sequence<size_t, N>; - -// index_sequence_for -// -// Converts a typename pack into an index sequence of the same length, and -// is designed to be a drop-in replacement for C++14's -// `std::index_sequence_for()` -template <typename... Ts> -using index_sequence_for = make_index_sequence<sizeof...(Ts)>; - -// Tag types - -#ifdef ABSL_USES_STD_OPTIONAL - -using std::in_place_t; -using std::in_place; - -#else // ABSL_USES_STD_OPTIONAL - -// in_place_t -// -// Tag type used to specify in-place construction, such as with -// `absl::optional`, designed to be a drop-in replacement for C++17's -// `std::in_place_t`. -struct in_place_t {}; - -ABSL_INTERNAL_INLINE_CONSTEXPR(in_place_t, in_place, {}); - -#endif // ABSL_USES_STD_OPTIONAL - -#if defined(ABSL_USES_STD_ANY) || defined(ABSL_USES_STD_VARIANT) -using std::in_place_type; -using std::in_place_type_t; -#else - -// in_place_type_t -// -// Tag type used for in-place construction when the type to construct needs to -// be specified, such as with `absl::any`, designed to be a drop-in replacement -// for C++17's `std::in_place_type_t`. -template <typename T> -using in_place_type_t = void (*)(utility_internal::InPlaceTypeTag<T>); - -template <typename T> -void in_place_type(utility_internal::InPlaceTypeTag<T>) {} -#endif // ABSL_USES_STD_ANY || ABSL_USES_STD_VARIANT - -#ifdef ABSL_USES_STD_VARIANT -using std::in_place_index; -using std::in_place_index_t; -#else - -// in_place_index_t -// -// Tag type used for in-place construction when the type to construct needs to -// be specified, such as with `absl::any`, designed to be a drop-in replacement -// for C++17's `std::in_place_index_t`. -template <size_t I> -using in_place_index_t = void (*)(utility_internal::InPlaceIndexTag<I>); - -template <size_t I> -void in_place_index(utility_internal::InPlaceIndexTag<I>) {} -#endif // ABSL_USES_STD_VARIANT - -// Constexpr move and forward - -// move() -// -// A constexpr version of `std::move()`, designed to be a drop-in replacement -// for C++14's `std::move()`. -template <typename T> -constexpr absl::remove_reference_t<T>&& move(T&& t) noexcept { - return static_cast<absl::remove_reference_t<T>&&>(t); -} - -// forward() -// -// A constexpr version of `std::forward()`, designed to be a drop-in replacement -// for C++14's `std::forward()`. -template <typename T> -constexpr T&& forward( - absl::remove_reference_t<T>& t) noexcept { // NOLINT(runtime/references) - return static_cast<T&&>(t); -} - -namespace utility_internal { -// Helper method for expanding tuple into a called method. -template <typename Functor, typename Tuple, std::size_t... Indexes> -auto apply_helper(Functor&& functor, Tuple&& t, index_sequence<Indexes...>) - -> decltype(absl::base_internal::invoke( - absl::forward<Functor>(functor), - std::get<Indexes>(absl::forward<Tuple>(t))...)) { - return absl::base_internal::invoke( - absl::forward<Functor>(functor), - std::get<Indexes>(absl::forward<Tuple>(t))...); -} - -} // namespace utility_internal - -// apply -// -// Invokes a Callable using elements of a tuple as its arguments. -// Each element of the tuple corresponds to an argument of the call (in order). -// Both the Callable argument and the tuple argument are perfect-forwarded. -// For member-function Callables, the first tuple element acts as the `this` -// pointer. `absl::apply` is designed to be a drop-in replacement for C++17's -// `std::apply`. Unlike C++17's `std::apply`, this is not currently `constexpr`. -// -// Example: -// -// class Foo { -// public: -// void Bar(int); -// }; -// void user_function1(int, std::string); -// void user_function2(std::unique_ptr<Foo>); -// auto user_lambda = [](int, int) {}; -// -// int main() -// { -// std::tuple<int, std::string> tuple1(42, "bar"); -// // Invokes the first user function on int, std::string. -// absl::apply(&user_function1, tuple1); -// -// std::tuple<std::unique_ptr<Foo>> tuple2(absl::make_unique<Foo>()); -// // Invokes the user function that takes ownership of the unique -// // pointer. -// absl::apply(&user_function2, std::move(tuple2)); -// -// auto foo = absl::make_unique<Foo>(); -// std::tuple<Foo*, int> tuple3(foo.get(), 42); -// // Invokes the method Bar on foo with one argument, 42. -// absl::apply(&Foo::Bar, tuple3); -// -// std::tuple<int, int> tuple4(8, 9); -// // Invokes a lambda. -// absl::apply(user_lambda, tuple4); -// } -template <typename Functor, typename Tuple> -auto apply(Functor&& functor, Tuple&& t) - -> decltype(utility_internal::apply_helper( - absl::forward<Functor>(functor), absl::forward<Tuple>(t), - absl::make_index_sequence<std::tuple_size< - typename std::remove_reference<Tuple>::type>::value>{})) { - return utility_internal::apply_helper( - absl::forward<Functor>(functor), absl::forward<Tuple>(t), - absl::make_index_sequence<std::tuple_size< - typename std::remove_reference<Tuple>::type>::value>{}); -} - -// exchange -// -// Replaces the value of `obj` with `new_value` and returns the old value of -// `obj`. `absl::exchange` is designed to be a drop-in replacement for C++14's -// `std::exchange`. -// -// Example: -// -// Foo& operator=(Foo&& other) { -// ptr1_ = absl::exchange(other.ptr1_, nullptr); -// int1_ = absl::exchange(other.int1_, -1); -// return *this; -// } -template <typename T, typename U = T> -T exchange(T& obj, U&& new_value) { - T old_value = absl::move(obj); - obj = absl::forward<U>(new_value); - return old_value; -} - -namespace utility_internal { -template <typename T, typename Tuple, size_t... I> -T make_from_tuple_impl(Tuple&& tup, absl::index_sequence<I...>) { - return T(std::get<I>(std::forward<Tuple>(tup))...); -} -} // namespace utility_internal - -// make_from_tuple -// -// Given the template parameter type `T` and a tuple of arguments -// `std::tuple(arg0, arg1, ..., argN)` constructs an object of type `T` as if by -// calling `T(arg0, arg1, ..., argN)`. -// -// Example: -// -// std::tuple<const char*, size_t> args("hello world", 5); -// auto s = absl::make_from_tuple<std::string>(args); -// assert(s == "hello"); -// -template <typename T, typename Tuple> -constexpr T make_from_tuple(Tuple&& tup) { - return utility_internal::make_from_tuple_impl<T>( - std::forward<Tuple>(tup), - absl::make_index_sequence< - std::tuple_size<absl::decay_t<Tuple>>::value>{}); -} - -ABSL_NAMESPACE_END -} // namespace absl - -#endif // ABSL_UTILITY_UTILITY_H_ |