diff options
Diffstat (limited to 'third_party/abseil_cpp/absl/functional/internal')
| -rw-r--r-- | third_party/abseil_cpp/absl/functional/internal/front_binder.h | 95 | ||||
| -rw-r--r-- | third_party/abseil_cpp/absl/functional/internal/function_ref.h | 106 |
2 files changed, 201 insertions, 0 deletions
diff --git a/third_party/abseil_cpp/absl/functional/internal/front_binder.h b/third_party/abseil_cpp/absl/functional/internal/front_binder.h new file mode 100644 index 000000000000..a4d95da44a7d --- /dev/null +++ b/third_party/abseil_cpp/absl/functional/internal/front_binder.h @@ -0,0 +1,95 @@ +// Copyright 2018 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. + +// Implementation details for `absl::bind_front()`. + +#ifndef ABSL_FUNCTIONAL_INTERNAL_FRONT_BINDER_H_ +#define ABSL_FUNCTIONAL_INTERNAL_FRONT_BINDER_H_ + +#include <cstddef> +#include <type_traits> +#include <utility> + +#include "absl/base/internal/invoke.h" +#include "absl/container/internal/compressed_tuple.h" +#include "absl/meta/type_traits.h" +#include "absl/utility/utility.h" + +namespace absl { +ABSL_NAMESPACE_BEGIN +namespace functional_internal { + +// Invoke the method, expanding the tuple of bound arguments. +template <class R, class Tuple, size_t... Idx, class... Args> +R Apply(Tuple&& bound, absl::index_sequence<Idx...>, Args&&... free) { + return base_internal::Invoke( + absl::forward<Tuple>(bound).template get<Idx>()..., + absl::forward<Args>(free)...); +} + +template <class F, class... BoundArgs> +class FrontBinder { + using BoundArgsT = absl::container_internal::CompressedTuple<F, BoundArgs...>; + using Idx = absl::make_index_sequence<sizeof...(BoundArgs) + 1>; + + BoundArgsT bound_args_; + + public: + template <class... Ts> + constexpr explicit FrontBinder(absl::in_place_t, Ts&&... ts) + : bound_args_(absl::forward<Ts>(ts)...) {} + + template <class... FreeArgs, + class R = base_internal::InvokeT<F&, BoundArgs&..., FreeArgs&&...>> + R operator()(FreeArgs&&... free_args) & { + return functional_internal::Apply<R>(bound_args_, Idx(), + absl::forward<FreeArgs>(free_args)...); + } + + template <class... FreeArgs, + class R = base_internal::InvokeT<const F&, const BoundArgs&..., + FreeArgs&&...>> + R operator()(FreeArgs&&... free_args) const& { + return functional_internal::Apply<R>(bound_args_, Idx(), + absl::forward<FreeArgs>(free_args)...); + } + + template <class... FreeArgs, class R = base_internal::InvokeT< + F&&, BoundArgs&&..., FreeArgs&&...>> + R operator()(FreeArgs&&... free_args) && { + // This overload is called when *this is an rvalue. If some of the bound + // arguments are stored by value or rvalue reference, we move them. + return functional_internal::Apply<R>(absl::move(bound_args_), Idx(), + absl::forward<FreeArgs>(free_args)...); + } + + template <class... FreeArgs, + class R = base_internal::InvokeT<const F&&, const BoundArgs&&..., + FreeArgs&&...>> + R operator()(FreeArgs&&... free_args) const&& { + // This overload is called when *this is an rvalue. If some of the bound + // arguments are stored by value or rvalue reference, we move them. + return functional_internal::Apply<R>(absl::move(bound_args_), Idx(), + absl::forward<FreeArgs>(free_args)...); + } +}; + +template <class F, class... BoundArgs> +using bind_front_t = FrontBinder<decay_t<F>, absl::decay_t<BoundArgs>...>; + +} // namespace functional_internal +ABSL_NAMESPACE_END +} // namespace absl + +#endif // ABSL_FUNCTIONAL_INTERNAL_FRONT_BINDER_H_ diff --git a/third_party/abseil_cpp/absl/functional/internal/function_ref.h b/third_party/abseil_cpp/absl/functional/internal/function_ref.h new file mode 100644 index 000000000000..d1575054eaf7 --- /dev/null +++ b/third_party/abseil_cpp/absl/functional/internal/function_ref.h @@ -0,0 +1,106 @@ +// Copyright 2019 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. + +#ifndef ABSL_FUNCTIONAL_INTERNAL_FUNCTION_REF_H_ +#define ABSL_FUNCTIONAL_INTERNAL_FUNCTION_REF_H_ + +#include <cassert> +#include <functional> +#include <type_traits> + +#include "absl/base/internal/invoke.h" +#include "absl/meta/type_traits.h" + +namespace absl { +ABSL_NAMESPACE_BEGIN +namespace functional_internal { + +// Like a void* that can handle function pointers as well. The standard does not +// allow function pointers to round-trip through void*, but void(*)() is fine. +// +// Note: It's important that this class remains trivial and is the same size as +// a pointer, since this allows the compiler to perform tail-call optimizations +// when the underlying function is a callable object with a matching signature. +union VoidPtr { + const void* obj; + void (*fun)(); +}; + +// Chooses the best type for passing T as an argument. +// Attempt to be close to SystemV AMD64 ABI. Objects with trivial copy ctor are +// passed by value. +template <typename T> +constexpr bool PassByValue() { + return !std::is_lvalue_reference<T>::value && + absl::is_trivially_copy_constructible<T>::value && + absl::is_trivially_copy_assignable< + typename std::remove_cv<T>::type>::value && + std::is_trivially_destructible<T>::value && + sizeof(T) <= 2 * sizeof(void*); +} + +template <typename T> +struct ForwardT : std::conditional<PassByValue<T>(), T, T&&> {}; + +// An Invoker takes a pointer to the type-erased invokable object, followed by +// the arguments that the invokable object expects. +// +// Note: The order of arguments here is an optimization, since member functions +// have an implicit "this" pointer as their first argument, putting VoidPtr +// first allows the compiler to perform tail-call optimization in many cases. +template <typename R, typename... Args> +using Invoker = R (*)(VoidPtr, typename ForwardT<Args>::type...); + +// +// InvokeObject and InvokeFunction provide static "Invoke" functions that can be +// used as Invokers for objects or functions respectively. +// +// static_cast<R> handles the case the return type is void. +template <typename Obj, typename R, typename... Args> +R InvokeObject(VoidPtr ptr, typename ForwardT<Args>::type... args) { + auto o = static_cast<const Obj*>(ptr.obj); + return static_cast<R>( + absl::base_internal::Invoke(*o, std::forward<Args>(args)...)); +} + +template <typename Fun, typename R, typename... Args> +R InvokeFunction(VoidPtr ptr, typename ForwardT<Args>::type... args) { + auto f = reinterpret_cast<Fun>(ptr.fun); + return static_cast<R>( + absl::base_internal::Invoke(f, std::forward<Args>(args)...)); +} + +template <typename Sig> +void AssertNonNull(const std::function<Sig>& f) { + assert(f != nullptr); + (void)f; +} + +template <typename F> +void AssertNonNull(const F&) {} + +template <typename F, typename C> +void AssertNonNull(F C::*f) { + assert(f != nullptr); + (void)f; +} + +template <bool C> +using EnableIf = typename ::std::enable_if<C, int>::type; + +} // namespace functional_internal +ABSL_NAMESPACE_END +} // namespace absl + +#endif // ABSL_FUNCTIONAL_INTERNAL_FUNCTION_REF_H_ |