TensorRT-LLMs/cpp/include/tensorrt_llm/common/optionalRef.h
Yihan Wang 9df4dad3b6
[None][fix] Introduce inline namespace to avoid symbol collision (#9541)
Signed-off-by: Yihan Wang <yihwang@nvidia.com>
2025-12-12 23:32:15 +08:00

110 lines
2.8 KiB
C++

/*
* Copyright (c) 2024, NVIDIA CORPORATION. All rights reserved.
*
* 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 "tensorrt_llm/common/config.h"
#include <functional>
#include <memory>
#include <optional>
TRTLLM_NAMESPACE_BEGIN
namespace common
{
/**
* @brief Wrapper that holds an optional reference and integrates with std containers.
* @details The wrapper uses a std::optional<std::reference_wrapper<T>> at its core.
When constructed with a unique or shared ptr with a nullptr value, it is interpreted as not holding a value,
meaning the std::optional of the wrapper object will be false.
*
* @tparam T
*/
template <typename T>
class OptionalRef
{
private:
std::optional<std::reference_wrapper<T>> opt;
public:
OptionalRef() = default;
OptionalRef(T& ref)
: opt(std::ref(ref))
{
}
OptionalRef(std::nullopt_t)
: opt(std::nullopt)
{
}
OptionalRef(std::shared_ptr<T> const& ptr)
: opt(ptr ? std::optional<std::reference_wrapper<T>>(std::ref(*ptr)) : std::nullopt)
{
}
// Constructor for std::shared_ptr<std::remove_const_t<T>> when T is const-qualified
template <typename U = T, typename = std::enable_if_t<std::is_const_v<U>>>
OptionalRef(std::shared_ptr<std::remove_const_t<T>> const& ptr)
: opt(ptr ? std::optional<std::reference_wrapper<T>>(std::ref(*ptr)) : std::nullopt)
{
}
OptionalRef(std::unique_ptr<T> const& ptr)
: opt(ptr ? std::optional<std::reference_wrapper<T>>(std::ref(*ptr)) : std::nullopt)
{
}
// Constructor for std::unique_ptr<std::remove_const_t<T>> when T is const-qualified
template <typename U = T, typename = std::enable_if_t<std::is_const_v<U>>>
OptionalRef(std::unique_ptr<std::remove_const_t<T>> const& ptr)
: opt(ptr ? std::optional<std::reference_wrapper<T>>(std::ref(*ptr)) : std::nullopt)
{
}
T* operator->() const
{
return opt ? &(opt->get()) : nullptr;
}
T& operator*() const
{
return opt->get();
}
explicit operator bool() const
{
return opt.has_value();
}
bool has_value() const
{
return opt.has_value();
}
T& value() const
{
return opt->get();
}
};
} // namespace common
TRTLLM_NAMESPACE_END