creation.hpp🔗

Namespaces🔗

Name
DesignPattern

Classes🔗

Name

class DesignPattern::Creation
This pattern can be used if you write an abstraction where you have to throw an exception in the constructor when you for instance would like to manage a resource and the constructor was unable to acquire that resource. In this case you inherit from [Creation]() and your class has three more static factory methods - create, placementCreate and verify. create forwards all arguments to the underlying class constructor and if the construction was successful an expected containing the type is returned, otherwise an error value which describes the error. Additionally, this class is providing two protected member variables m_isInitialized and m_errorValue. The user always has to set m_isInitialized to true when the object construction was successful otherwise one sets it to false and write the corresponding error cause in the provided m_errorValue variable which is then returned to the user.

Source code🔗

// Copyright (c) 2019 by Robert Bosch GmbH. All rights reserved.
// Copyright (c) 2021 by Apex.AI Inc. 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.
//
// SPDX-License-Identifier: Apache-2.0
#ifndef IOX_HOOFS_DESIGN_PATTERN_CREATION_HPP
#define IOX_HOOFS_DESIGN_PATTERN_CREATION_HPP

#include "iceoryx_hoofs/cxx/expected.hpp"

#include <utility>

namespace DesignPattern
{
template <typename DerivedClass, typename ErrorType>
class Creation
{
  public:
    using CreationPattern_t = Creation<DerivedClass, ErrorType>;
    using result_t = iox::cxx::expected<DerivedClass, ErrorType>;
    using errorType_t = ErrorType;

    template <typename... Targs>
    static result_t create(Targs&&... args) noexcept;

    static result_t verify(DerivedClass&& newObject) noexcept;

    template <typename... Targs>
    static iox::cxx::expected<ErrorType> placementCreate(void* const memory, Targs&&... args) noexcept;

    Creation() noexcept = default;
    Creation(Creation&& rhs) noexcept;

    Creation& operator=(Creation&& rhs) noexcept;
    Creation(const Creation& rhs) noexcept = default;
    Creation& operator=(const Creation& rhs) noexcept = default;

    bool isInitialized() const noexcept;

  protected:
    bool m_isInitialized{false};
    ErrorType m_errorValue;
};

} // namespace DesignPattern

#include "iceoryx_hoofs/internal/design_pattern/creation.inl"

#endif // IOX_HOOFS_DESIGN_PATTERN_CREATION_HPP

Updated on 2 April 2022 at 16:37:47 CEST