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| 1 | +/* |
| 2 | + * Licensed to the Apache Software Foundation (ASF) under one |
| 3 | + * or more contributor license agreements. See the NOTICE file |
| 4 | + * distributed with this work for additional information |
| 5 | + * regarding copyright ownership. The ASF licenses this file |
| 6 | + * to you under the Apache License, Version 2.0 (the |
| 7 | + * "License"); you may not use this file except in compliance |
| 8 | + * with the License. You may obtain a copy of the License at |
| 9 | + * |
| 10 | + * http://www.apache.org/licenses/LICENSE-2.0 |
| 11 | + * |
| 12 | + * Unless required by applicable law or agreed to in writing, |
| 13 | + * software distributed under the License is distributed on an |
| 14 | + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| 15 | + * KIND, either express or implied. See the License for the |
| 16 | + * specific language governing permissions and limitations |
| 17 | + * under the License. |
| 18 | + */ |
| 19 | +/*! |
| 20 | + * \file tvm/node/cast.h |
| 21 | + * \brief Value casting helpers |
| 22 | + */ |
| 23 | +#ifndef TVM_NODE_CAST_H_ |
| 24 | +#define TVM_NODE_CAST_H_ |
| 25 | + |
| 26 | +#include <tvm/ffi/any.h> |
| 27 | +#include <tvm/ffi/cast.h> |
| 28 | +#include <tvm/ffi/dtype.h> |
| 29 | +#include <tvm/ffi/error.h> |
| 30 | +#include <tvm/ffi/object.h> |
| 31 | +#include <tvm/ffi/optional.h> |
| 32 | + |
| 33 | +#include <utility> |
| 34 | + |
| 35 | +namespace tvm { |
| 36 | + |
| 37 | +/*! |
| 38 | + * \brief Downcast a base reference type to a more specific type. |
| 39 | + * |
| 40 | + * \param ref The input reference |
| 41 | + * \return The corresponding SubRef. |
| 42 | + * \tparam SubRef The target specific reference type. |
| 43 | + * \tparam BaseRef the current reference type. |
| 44 | + */ |
| 45 | +template <typename SubRef, typename BaseRef, |
| 46 | + typename = std::enable_if_t<std::is_base_of_v<ffi::ObjectRef, BaseRef>>> |
| 47 | +inline SubRef Downcast(BaseRef ref) { |
| 48 | + if (ref.defined()) { |
| 49 | + if (!ref->template IsInstance<typename SubRef::ContainerType>()) { |
| 50 | + TVM_FFI_THROW(TypeError) << "Downcast from " << ref->GetTypeKey() << " to " |
| 51 | + << SubRef::ContainerType::_type_key << " failed."; |
| 52 | + } |
| 53 | + return SubRef(ffi::details::ObjectUnsafe::ObjectPtrFromObjectRef<ffi::Object>(std::move(ref))); |
| 54 | + } else { |
| 55 | + if constexpr (ffi::is_optional_type_v<SubRef> || SubRef::_type_is_nullable) { |
| 56 | + return SubRef(ffi::ObjectPtr<ffi::Object>(nullptr)); |
| 57 | + } |
| 58 | + TVM_FFI_THROW(TypeError) << "Downcast from undefined(nullptr) to `" |
| 59 | + << SubRef::ContainerType::_type_key |
| 60 | + << "` is not allowed. Use Downcast<Optional<T>> instead."; |
| 61 | + TVM_FFI_UNREACHABLE(); |
| 62 | + } |
| 63 | +} |
| 64 | + |
| 65 | +/*! |
| 66 | + * \brief Downcast any to a specific type |
| 67 | + * |
| 68 | + * \param ref The input reference |
| 69 | + * \return The corresponding SubRef. |
| 70 | + * \tparam T The target specific reference type. |
| 71 | + */ |
| 72 | +template <typename T> |
| 73 | +inline T Downcast(const ffi::Any& ref) { |
| 74 | + if constexpr (std::is_same_v<T, Any>) { |
| 75 | + return ref; |
| 76 | + } else { |
| 77 | + return ref.cast<T>(); |
| 78 | + } |
| 79 | +} |
| 80 | + |
| 81 | +/*! |
| 82 | + * \brief Downcast any to a specific type |
| 83 | + * |
| 84 | + * \param ref The input reference |
| 85 | + * \return The corresponding SubRef. |
| 86 | + * \tparam T The target specific reference type. |
| 87 | + */ |
| 88 | +template <typename T> |
| 89 | +inline T Downcast(ffi::Any&& ref) { |
| 90 | + if constexpr (std::is_same_v<T, Any>) { |
| 91 | + return std::move(ref); |
| 92 | + } else { |
| 93 | + return std::move(ref).cast<T>(); |
| 94 | + } |
| 95 | +} |
| 96 | + |
| 97 | +/*! |
| 98 | + * \brief Downcast std::optional<Any> to std::optional<T> |
| 99 | + * |
| 100 | + * \param ref The input reference |
| 101 | + * \return The corresponding SubRef. |
| 102 | + * \tparam OptionalType The target optional type |
| 103 | + */ |
| 104 | +template <typename OptionalType, typename = std::enable_if_t<ffi::is_optional_type_v<OptionalType>>> |
| 105 | +inline OptionalType Downcast(const std::optional<ffi::Any>& ref) { |
| 106 | + if (ref.has_value()) { |
| 107 | + if constexpr (std::is_same_v<OptionalType, ffi::Any>) { |
| 108 | + return *ref; |
| 109 | + } else { |
| 110 | + return (*ref).cast<OptionalType>(); |
| 111 | + } |
| 112 | + } else { |
| 113 | + return OptionalType(std::nullopt); |
| 114 | + } |
| 115 | +} |
| 116 | +} // namespace tvm |
| 117 | +#endif // TVM_NODE_CAST_H_ |
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