Program Listing for File parameter.hpp

            

            
/*
* SPDX-FileCopyrightText: Copyright (c) 2022 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
* SPDX-License-Identifier: Apache-2.0
*
* 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.
*/

#ifndef HOLOSCAN_CORE_PARAMETER_HPP
#define HOLOSCAN_CORE_PARAMETER_HPP

#include <any>
#include <functional>
#include <iostream>
#include <optional>
#include <string>
#include <typeinfo>
#include <utility>

#include "./common.hpp"
#include "./arg.hpp"

namespace holoscan {

enum class ParameterFlag {
  kNone = 0,
  kOptional = 1,
  kDynamic = 2,
};

class ParameterWrapper {
 public:
  ParameterWrapper() = default;

  template <typename typeT>
  explicit ParameterWrapper(Parameter<typeT>& param)
      : type_(&typeid(typeT)), arg_type_(ArgType::create<typeT>()), value_(&param) {}


  ParameterWrapper(std::any value, const std::type_info* type, const ArgType& arg_type)
      : type_(type), arg_type_(arg_type), value_(std::move(value)) {}

  const std::type_info& type() const {
    if (type_) { return *type_; }
    return typeid(void);
  }
  const ArgType& arg_type() const { return arg_type_; }

  std::any& value() { return value_; }

 private:
  const std::type_info* type_ = nullptr;
  ArgType arg_type_;
  std::any value_;
};

template <typename ValueT>
class MetaParameter {
 public:
  MetaParameter() = default;

  explicit MetaParameter(ValueT& value) : value_(value) {}
  explicit MetaParameter(ValueT&& value) : value_(std::move(value)) {}

  MetaParameter& operator=(const ValueT& value) {
    value_ = value;
    return *this;
  }
  MetaParameter&& operator=(ValueT&& value) {
    value_ = std::move(value);
    return std::move(*this);
  }

  const std::string& key() const { return key_; }

  bool has_value() const { return value_.has_value(); }

  ValueT& get() {
    if (value_.has_value()) {
      return value_.value();
    } else {
      throw std::runtime_error(fmt::format("MetaParameter: value for '{}' is not set", key_));
    }
  }

  void set_default_value() {
    if (!value_.has_value()) { value_ = default_value_; }
  }

  ValueT& default_value() {
    if (default_value_.has_value()) {
      return default_value_.value();
    } else {
      throw std::runtime_error(
        fmt::format("MetaParameter: default value for '{}' is not set", key_));
    }
  }

  bool has_default_value() const { return default_value_.has_value(); }

  operator ValueT&() { return get(); }

 private:
  friend class ComponentSpec;
  friend class OperatorSpec;
  std::optional<ValueT> value_;
  std::optional<ValueT> default_value_;
  std::string key_;
  std::string headline_;
  std::string description_;
  ParameterFlag flag_ = ParameterFlag::kNone;
};

}  // namespace holoscan

#endif/* HOLOSCAN_CORE_PARAMETER_HPP */