archiveFrom_std_streams.h

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2020, Individual contributors, see AUTHORS file     |
   | See: https://www.mrpt.org/Authors - All rights reserved.               |
   | Released under BSD License. See: https://www.mrpt.org/License          |
   +------------------------------------------------------------------------+ */
#pragma once

#include <mrpt/serialization/CArchive.h>
#include <iosfwd>
#include <istream>
#include <ostream>

namespace mrpt::serialization
{
/** Specialization for std::istream */
template <>
class CArchiveStreamBase<std::istream> : public CArchive
{
    std::istream& m_s;

   public:
    CArchiveStreamBase(std::istream& s) : m_s(s) {}

   protected:
    size_t write(const void* d, size_t n) override
    {
        throw std::runtime_error(
            "CArchiveStreamBase<std::istream>:"
            "cannot write to an input stream.");
    }
    size_t read(void* d, size_t n) override
    {
        if (m_s.read(reinterpret_cast<char*>(d), n))
            return n;
        else
            return 0;
    }
};

/** Specialization for std::ostream */
template <>
class CArchiveStreamBase<std::ostream> : public CArchive
{
    std::ostream& m_s;

   public:
    CArchiveStreamBase(std::ostream& s) : m_s(s) {}

   protected:
    size_t write(const void* d, size_t n) override
    {
        if (m_s.write(reinterpret_cast<const char*>(d), n))
            return n;
        else
            return 0;
    }
    size_t read(void* d, size_t n) override
    {
        throw std::runtime_error(
            "CArchiveStreamBase<std::ostream>:"
            "cannot read from output stream.");
    }
};

/** Specialization for std::iostream */
template <>
class CArchiveStreamBase<std::iostream> : public CArchive
{
    std::iostream& m_s;

   public:
    CArchiveStreamBase(std::iostream& s) : m_s(s) {}

   protected:
    size_t write(const void* d, size_t n) override
    {
        if (m_s.write(reinterpret_cast<const char*>(d), n))
            return n;
        else
            return 0;
    }
    size_t read(void* d, size_t n) override
    {
        if (m_s.read(reinterpret_cast<char*>(d), n))
            return n;
        else
            return 0;
    }
};

}  // namespace mrpt::serialization