blame: source/code/Libs/include/cereal/external/rapidjson/istreamwrapper.h

// Tencent is pleased to support the open source community by making RapidJSON available.

//

// Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. All rights reserved.

//

// Licensed under the MIT License (the "License"); you may not use this file except

// in compliance with the License. You may obtain a copy of the License at

//

// http://opensource.org/licenses/MIT

//

// 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 CEREAL_RAPIDJSON_ISTREAMWRAPPER_H_

#define CEREAL_RAPIDJSON_ISTREAMWRAPPER_H_

#include "stream.h"

#include <iosfwd>

#ifdef __clang__

CEREAL_RAPIDJSON_DIAG_PUSH

CEREAL_RAPIDJSON_DIAG_OFF(padded)

#endif

#ifdef _MSC_VER

CEREAL_RAPIDJSON_DIAG_PUSH

CEREAL_RAPIDJSON_DIAG_OFF(4351) // new behavior: elements of array 'array' will be default initialized

CEREAL_RAPIDJSON_DIAG_OFF(4127) // ignore assert(false) for triggering exception

#endif

CEREAL_RAPIDJSON_NAMESPACE_BEGIN

//! Wrapper of \c std::basic_istream into RapidJSON's Stream concept.

/*!

    The classes can be wrapped including but not limited to:

    - \c std::istringstream

    - \c std::stringstream

    - \c std::wistringstream

    - \c std::wstringstream

    - \c std::ifstream

    - \c std::fstream

    - \c std::wifstream

    - \c std::wfstream

    \tparam StreamType Class derived from \c std::basic_istream.

*/

template <typename StreamType>

class BasicIStreamWrapper {

public:

    typedef typename StreamType::char_type Ch;

    BasicIStreamWrapper(StreamType& stream) : stream_(stream), count_(), peekBuffer_() {}

    Ch Peek() const {

        typename StreamType::int_type c = stream_.peek();

        return CEREAL_RAPIDJSON_LIKELY(c != StreamType::traits_type::eof()) ? static_cast<Ch>(c) : '\0';

    }

    Ch Take() {

        typename StreamType::int_type c = stream_.get();

        if (CEREAL_RAPIDJSON_LIKELY(c != StreamType::traits_type::eof())) {

            count_++;

            return static_cast<Ch>(c);

        }

        else

            return '\0';

    }

    // tellg() may return -1 when failed. So we count by ourself.

    size_t Tell() const { return count_; }

    Ch* PutBegin() { CEREAL_RAPIDJSON_ASSERT(false); return 0; }

    void Put(Ch) { CEREAL_RAPIDJSON_ASSERT(false); }

    void Flush() { CEREAL_RAPIDJSON_ASSERT(false); }

    size_t PutEnd(Ch*) { CEREAL_RAPIDJSON_ASSERT(false); return 0; }

    // For encoding detection only.

    const Ch* Peek4() const {

        CEREAL_RAPIDJSON_ASSERT(sizeof(Ch) == 1); // Only usable for byte stream.

        int i;

        bool hasError = false;

        for (i = 0; i < 4; ++i) {

            typename StreamType::int_type c = stream_.get();

            if (c == StreamType::traits_type::eof()) {

                hasError = true;

                stream_.clear();

                break;

            }

            peekBuffer_[i] = static_cast<Ch>(c);

        }

        for (--i; i >= 0; --i)

            stream_.putback(peekBuffer_[i]);

        return !hasError ? peekBuffer_ : 0;

    }

private:

    BasicIStreamWrapper(const BasicIStreamWrapper&);

    BasicIStreamWrapper& operator=(const BasicIStreamWrapper&);

    StreamType& stream_;

    size_t count_;  //!< Number of characters read. Note:

    mutable Ch peekBuffer_[4];

};

typedef BasicIStreamWrapper<std::istream> IStreamWrapper;

typedef BasicIStreamWrapper<std::wistream> WIStreamWrapper;

#if defined(__clang__) || defined(_MSC_VER)

CEREAL_RAPIDJSON_DIAG_POP

#endif

CEREAL_RAPIDJSON_NAMESPACE_END

#endif // CEREAL_RAPIDJSON_ISTREAMWRAPPER_H_