Abseil Common Libraries (C++) (grcp 依赖)
https://abseil.io/
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
95 lines
3.6 KiB
95 lines
3.6 KiB
// 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_
|
|
|