buffer.hpp

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//
// buffer.hpp
// ~~~~~~~~~~
//
// Copyright (c) 2003-2015 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//

#ifndef ASIO_BUFFER_HPP
#define ASIO_BUFFER_HPP

#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)

#include "asio/detail/config.hpp"
#include <cstddef>
#include <cstring>
#include <string>
#include <vector>
#include "asio/detail/array_fwd.hpp"

#if defined(ASIO_MSVC)
# if defined(_HAS_ITERATOR_DEBUGGING) && (_HAS_ITERATOR_DEBUGGING != 0)
#  if !defined(ASIO_DISABLE_BUFFER_DEBUGGING)
#   define ASIO_ENABLE_BUFFER_DEBUGGING
#  endif // !defined(ASIO_DISABLE_BUFFER_DEBUGGING)
# endif // defined(_HAS_ITERATOR_DEBUGGING)
#endif // defined(ASIO_MSVC)

#if defined(__GNUC__)
# if defined(_GLIBCXX_DEBUG)
#  if !defined(ASIO_DISABLE_BUFFER_DEBUGGING)
#   define ASIO_ENABLE_BUFFER_DEBUGGING
#  endif // !defined(ASIO_DISABLE_BUFFER_DEBUGGING)
# endif // defined(_GLIBCXX_DEBUG)
#endif // defined(__GNUC__)

#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
# include "asio/detail/function.hpp"
#endif // ASIO_ENABLE_BUFFER_DEBUGGING

#if defined(ASIO_HAS_BOOST_WORKAROUND)
# include <boost/detail/workaround.hpp>
# if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x582)) \
    || BOOST_WORKAROUND(__SUNPRO_CC, BOOST_TESTED_AT(0x590))
#  define ASIO_ENABLE_ARRAY_BUFFER_WORKAROUND
# endif // BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x582))
        // || BOOST_WORKAROUND(__SUNPRO_CC, BOOST_TESTED_AT(0x590))
#endif // defined(ASIO_HAS_BOOST_WORKAROUND)

#if defined(ASIO_ENABLE_ARRAY_BUFFER_WORKAROUND)
# include "asio/detail/type_traits.hpp"
#endif // defined(ASIO_ENABLE_ARRAY_BUFFER_WORKAROUND)

#include "asio/detail/push_options.hpp"

namespace asio {

class mutable_buffer;
class const_buffer;

namespace detail {
void* buffer_cast_helper(const mutable_buffer&);
const void* buffer_cast_helper(const const_buffer&);
std::size_t buffer_size_helper(const mutable_buffer&);
std::size_t buffer_size_helper(const const_buffer&);
} // namespace detail


class mutable_buffer
{
public:
  mutable_buffer()
    : data_(0),
      size_(0)
  {
  }

  mutable_buffer(void* data, std::size_t size)
    : data_(data),
      size_(size)
  {
  }

#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
  mutable_buffer(void* data, std::size_t size,
      asio::detail::function<void()> debug_check)
    : data_(data),
      size_(size),
      debug_check_(debug_check)
  {
  }

  const asio::detail::function<void()>& get_debug_check() const
  {
    return debug_check_;
  }
#endif // ASIO_ENABLE_BUFFER_DEBUGGING

private:
  friend void* asio::detail::buffer_cast_helper(
      const mutable_buffer& b);
  friend std::size_t asio::detail::buffer_size_helper(
      const mutable_buffer& b);

  void* data_;
  std::size_t size_;

#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
  asio::detail::function<void()> debug_check_;
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
};

namespace detail {

inline void* buffer_cast_helper(const mutable_buffer& b)
{
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
  if (b.size_ && b.debug_check_)
    b.debug_check_();
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
  return b.data_;
}

inline std::size_t buffer_size_helper(const mutable_buffer& b)
{
  return b.size_;
}

} // namespace detail

class mutable_buffers_1
  : public mutable_buffer
{
public:
  typedef mutable_buffer value_type;

  typedef const mutable_buffer* const_iterator;

  mutable_buffers_1(void* data, std::size_t size)
    : mutable_buffer(data, size)
  {
  }

  explicit mutable_buffers_1(const mutable_buffer& b)
    : mutable_buffer(b)
  {
  }

  const_iterator begin() const
  {
    return this;
  }

  const_iterator end() const
  {
    return begin() + 1;
  }
};


class const_buffer
{
public:
  const_buffer()
    : data_(0),
      size_(0)
  {
  }

  const_buffer(const void* data, std::size_t size)
    : data_(data),
      size_(size)
  {
  }

  const_buffer(const mutable_buffer& b)
    : data_(asio::detail::buffer_cast_helper(b)),
      size_(asio::detail::buffer_size_helper(b))
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
      , debug_check_(b.get_debug_check())
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
  {
  }

#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
  const_buffer(const void* data, std::size_t size,
      asio::detail::function<void()> debug_check)
    : data_(data),
      size_(size),
      debug_check_(debug_check)
  {
  }

  const asio::detail::function<void()>& get_debug_check() const
  {
    return debug_check_;
  }
#endif // ASIO_ENABLE_BUFFER_DEBUGGING

private:
  friend const void* asio::detail::buffer_cast_helper(
      const const_buffer& b);
  friend std::size_t asio::detail::buffer_size_helper(
      const const_buffer& b);

  const void* data_;
  std::size_t size_;

#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
  asio::detail::function<void()> debug_check_;
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
};

namespace detail {

inline const void* buffer_cast_helper(const const_buffer& b)
{
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
  if (b.size_ && b.debug_check_)
    b.debug_check_();
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
  return b.data_;
}

inline std::size_t buffer_size_helper(const const_buffer& b)
{
  return b.size_;
}

} // namespace detail

class const_buffers_1
  : public const_buffer
{
public:
  typedef const_buffer value_type;

  typedef const const_buffer* const_iterator;

  const_buffers_1(const void* data, std::size_t size)
    : const_buffer(data, size)
  {
  }

  explicit const_buffers_1(const const_buffer& b)
    : const_buffer(b)
  {
  }

  const_iterator begin() const
  {
    return this;
  }

  const_iterator end() const
  {
    return begin() + 1;
  }
};

class null_buffers
{
public:
  typedef mutable_buffer value_type;

  typedef const mutable_buffer* const_iterator;

  const_iterator begin() const
  {
    return &buf_;
  }

  const_iterator end() const
  {
    return &buf_;
  }

private:
  mutable_buffer buf_;
};


inline std::size_t buffer_size(const mutable_buffer& b)
{
  return detail::buffer_size_helper(b);
}

inline std::size_t buffer_size(const mutable_buffers_1& b)
{
  return detail::buffer_size_helper(b);
}

inline std::size_t buffer_size(const const_buffer& b)
{
  return detail::buffer_size_helper(b);
}

inline std::size_t buffer_size(const const_buffers_1& b)
{
  return detail::buffer_size_helper(b);
}


template <typename BufferSequence>
inline std::size_t buffer_size(const BufferSequence& b)
{
  std::size_t total_buffer_size = 0;

  typename BufferSequence::const_iterator iter = b.begin();
  typename BufferSequence::const_iterator end = b.end();
  for (; iter != end; ++iter)
    total_buffer_size += detail::buffer_size_helper(*iter);

  return total_buffer_size;
}


template <typename PointerToPodType>
inline PointerToPodType buffer_cast(const mutable_buffer& b)
{
  return static_cast<PointerToPodType>(detail::buffer_cast_helper(b));
}

template <typename PointerToPodType>
inline PointerToPodType buffer_cast(const const_buffer& b)
{
  return static_cast<PointerToPodType>(detail::buffer_cast_helper(b));
}


inline mutable_buffer operator+(const mutable_buffer& b, std::size_t start)
{
  if (start > buffer_size(b))
    return mutable_buffer();
  char* new_data = buffer_cast<char*>(b) + start;
  std::size_t new_size = buffer_size(b) - start;
  return mutable_buffer(new_data, new_size
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
      , b.get_debug_check()
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
      );
}


inline mutable_buffer operator+(std::size_t start, const mutable_buffer& b)
{
  if (start > buffer_size(b))
    return mutable_buffer();
  char* new_data = buffer_cast<char*>(b) + start;
  std::size_t new_size = buffer_size(b) - start;
  return mutable_buffer(new_data, new_size
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
      , b.get_debug_check()
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
      );
}


inline const_buffer operator+(const const_buffer& b, std::size_t start)
{
  if (start > buffer_size(b))
    return const_buffer();
  const char* new_data = buffer_cast<const char*>(b) + start;
  std::size_t new_size = buffer_size(b) - start;
  return const_buffer(new_data, new_size
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
      , b.get_debug_check()
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
      );
}


inline const_buffer operator+(std::size_t start, const const_buffer& b)
{
  if (start > buffer_size(b))
    return const_buffer();
  const char* new_data = buffer_cast<const char*>(b) + start;
  std::size_t new_size = buffer_size(b) - start;
  return const_buffer(new_data, new_size
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
      , b.get_debug_check()
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
      );
}

#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
namespace detail {

template <typename Iterator>
class buffer_debug_check
{
public:
  buffer_debug_check(Iterator iter)
    : iter_(iter)
  {
  }

  ~buffer_debug_check()
  {
#if defined(ASIO_MSVC) && (ASIO_MSVC == 1400)
    // MSVC 8's string iterator checking may crash in a std::string::iterator
    // object's destructor when the iterator points to an already-destroyed
    // std::string object, unless the iterator is cleared first.
    iter_ = Iterator();
#endif // defined(ASIO_MSVC) && (ASIO_MSVC == 1400)
  }

  void operator()()
  {
    *iter_;
  }

private:
  Iterator iter_;
};

} // namespace detail
#endif // ASIO_ENABLE_BUFFER_DEBUGGING



inline mutable_buffers_1 buffer(const mutable_buffer& b)
{
  return mutable_buffers_1(b);
}


inline mutable_buffers_1 buffer(const mutable_buffer& b,
    std::size_t max_size_in_bytes)
{
  return mutable_buffers_1(
      mutable_buffer(buffer_cast<void*>(b),
        buffer_size(b) < max_size_in_bytes
        ? buffer_size(b) : max_size_in_bytes
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
        , b.get_debug_check()
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
        ));
}


inline const_buffers_1 buffer(const const_buffer& b)
{
  return const_buffers_1(b);
}


inline const_buffers_1 buffer(const const_buffer& b,
    std::size_t max_size_in_bytes)
{
  return const_buffers_1(
      const_buffer(buffer_cast<const void*>(b),
        buffer_size(b) < max_size_in_bytes
        ? buffer_size(b) : max_size_in_bytes
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
        , b.get_debug_check()
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
        ));
}


inline mutable_buffers_1 buffer(void* data, std::size_t size_in_bytes)
{
  return mutable_buffers_1(mutable_buffer(data, size_in_bytes));
}


inline const_buffers_1 buffer(const void* data,
    std::size_t size_in_bytes)
{
  return const_buffers_1(const_buffer(data, size_in_bytes));
}


template <typename PodType, std::size_t N>
inline mutable_buffers_1 buffer(PodType (&data)[N])
{
  return mutable_buffers_1(mutable_buffer(data, N * sizeof(PodType)));
}
 

template <typename PodType, std::size_t N>
inline mutable_buffers_1 buffer(PodType (&data)[N],
    std::size_t max_size_in_bytes)
{
  return mutable_buffers_1(
      mutable_buffer(data,
        N * sizeof(PodType) < max_size_in_bytes
        ? N * sizeof(PodType) : max_size_in_bytes));
}
 

template <typename PodType, std::size_t N>
inline const_buffers_1 buffer(const PodType (&data)[N])
{
  return const_buffers_1(const_buffer(data, N * sizeof(PodType)));
}


template <typename PodType, std::size_t N>
inline const_buffers_1 buffer(const PodType (&data)[N],
    std::size_t max_size_in_bytes)
{
  return const_buffers_1(
      const_buffer(data,
        N * sizeof(PodType) < max_size_in_bytes
        ? N * sizeof(PodType) : max_size_in_bytes));
}

#if defined(ASIO_ENABLE_ARRAY_BUFFER_WORKAROUND)

// Borland C++ and Sun Studio think the overloads:
//
//   unspecified buffer(boost::array<PodType, N>& array ...);
//
// and
//
//   unspecified buffer(boost::array<const PodType, N>& array ...);
//
// are ambiguous. This will be worked around by using a buffer_types traits
// class that contains typedefs for the appropriate buffer and container
// classes, based on whether PodType is const or non-const.

namespace detail {

template <bool IsConst>
struct buffer_types_base;

template <>
struct buffer_types_base<false>
{
  typedef mutable_buffer buffer_type;
  typedef mutable_buffers_1 container_type;
};

template <>
struct buffer_types_base<true>
{
  typedef const_buffer buffer_type;
  typedef const_buffers_1 container_type;
};

template <typename PodType>
struct buffer_types
  : public buffer_types_base<is_const<PodType>::value>
{
};

} // namespace detail

template <typename PodType, std::size_t N>
inline typename detail::buffer_types<PodType>::container_type
buffer(boost::array<PodType, N>& data)
{
  typedef typename asio::detail::buffer_types<PodType>::buffer_type
    buffer_type;
  typedef typename asio::detail::buffer_types<PodType>::container_type
    container_type;
  return container_type(
      buffer_type(data.c_array(), data.size() * sizeof(PodType)));
}

template <typename PodType, std::size_t N>
inline typename detail::buffer_types<PodType>::container_type
buffer(boost::array<PodType, N>& data, std::size_t max_size_in_bytes)
{
  typedef typename asio::detail::buffer_types<PodType>::buffer_type
    buffer_type;
  typedef typename asio::detail::buffer_types<PodType>::container_type
    container_type;
  return container_type(
      buffer_type(data.c_array(),
        data.size() * sizeof(PodType) < max_size_in_bytes
        ? data.size() * sizeof(PodType) : max_size_in_bytes));
}

#else // defined(ASIO_ENABLE_ARRAY_BUFFER_WORKAROUND)


template <typename PodType, std::size_t N>
inline mutable_buffers_1 buffer(boost::array<PodType, N>& data)
{
  return mutable_buffers_1(
      mutable_buffer(data.c_array(), data.size() * sizeof(PodType)));
}


template <typename PodType, std::size_t N>
inline mutable_buffers_1 buffer(boost::array<PodType, N>& data,
    std::size_t max_size_in_bytes)
{
  return mutable_buffers_1(
      mutable_buffer(data.c_array(),
        data.size() * sizeof(PodType) < max_size_in_bytes
        ? data.size() * sizeof(PodType) : max_size_in_bytes));
}


template <typename PodType, std::size_t N>
inline const_buffers_1 buffer(boost::array<const PodType, N>& data)
{
  return const_buffers_1(
      const_buffer(data.data(), data.size() * sizeof(PodType)));
}


template <typename PodType, std::size_t N>
inline const_buffers_1 buffer(boost::array<const PodType, N>& data,
    std::size_t max_size_in_bytes)
{
  return const_buffers_1(
      const_buffer(data.data(),
        data.size() * sizeof(PodType) < max_size_in_bytes
        ? data.size() * sizeof(PodType) : max_size_in_bytes));
}

#endif // defined(ASIO_ENABLE_ARRAY_BUFFER_WORKAROUND)


template <typename PodType, std::size_t N>
inline const_buffers_1 buffer(const boost::array<PodType, N>& data)
{
  return const_buffers_1(
      const_buffer(data.data(), data.size() * sizeof(PodType)));
}


template <typename PodType, std::size_t N>
inline const_buffers_1 buffer(const boost::array<PodType, N>& data,
    std::size_t max_size_in_bytes)
{
  return const_buffers_1(
      const_buffer(data.data(),
        data.size() * sizeof(PodType) < max_size_in_bytes
        ? data.size() * sizeof(PodType) : max_size_in_bytes));
}

#if defined(ASIO_HAS_STD_ARRAY) || defined(GENERATING_DOCUMENTATION)


template <typename PodType, std::size_t N>
inline mutable_buffers_1 buffer(std::array<PodType, N>& data)
{
  return mutable_buffers_1(
      mutable_buffer(data.data(), data.size() * sizeof(PodType)));
}


template <typename PodType, std::size_t N>
inline mutable_buffers_1 buffer(std::array<PodType, N>& data,
    std::size_t max_size_in_bytes)
{
  return mutable_buffers_1(
      mutable_buffer(data.data(),
        data.size() * sizeof(PodType) < max_size_in_bytes
        ? data.size() * sizeof(PodType) : max_size_in_bytes));
}


template <typename PodType, std::size_t N>
inline const_buffers_1 buffer(std::array<const PodType, N>& data)
{
  return const_buffers_1(
      const_buffer(data.data(), data.size() * sizeof(PodType)));
}


template <typename PodType, std::size_t N>
inline const_buffers_1 buffer(std::array<const PodType, N>& data,
    std::size_t max_size_in_bytes)
{
  return const_buffers_1(
      const_buffer(data.data(),
        data.size() * sizeof(PodType) < max_size_in_bytes
        ? data.size() * sizeof(PodType) : max_size_in_bytes));
}


template <typename PodType, std::size_t N>
inline const_buffers_1 buffer(const std::array<PodType, N>& data)
{
  return const_buffers_1(
      const_buffer(data.data(), data.size() * sizeof(PodType)));
}


template <typename PodType, std::size_t N>
inline const_buffers_1 buffer(const std::array<PodType, N>& data,
    std::size_t max_size_in_bytes)
{
  return const_buffers_1(
      const_buffer(data.data(),
        data.size() * sizeof(PodType) < max_size_in_bytes
        ? data.size() * sizeof(PodType) : max_size_in_bytes));
}

#endif // defined(ASIO_HAS_STD_ARRAY) || defined(GENERATING_DOCUMENTATION)


template <typename PodType, typename Allocator>
inline mutable_buffers_1 buffer(std::vector<PodType, Allocator>& data)
{
  return mutable_buffers_1(
      mutable_buffer(data.size() ? &data[0] : 0, data.size() * sizeof(PodType)
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
        , detail::buffer_debug_check<
            typename std::vector<PodType, Allocator>::iterator
          >(data.begin())
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
        ));
}


template <typename PodType, typename Allocator>
inline mutable_buffers_1 buffer(std::vector<PodType, Allocator>& data,
    std::size_t max_size_in_bytes)
{
  return mutable_buffers_1(
      mutable_buffer(data.size() ? &data[0] : 0,
        data.size() * sizeof(PodType) < max_size_in_bytes
        ? data.size() * sizeof(PodType) : max_size_in_bytes
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
        , detail::buffer_debug_check<
            typename std::vector<PodType, Allocator>::iterator
          >(data.begin())
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
        ));
}


template <typename PodType, typename Allocator>
inline const_buffers_1 buffer(
    const std::vector<PodType, Allocator>& data)
{
  return const_buffers_1(
      const_buffer(data.size() ? &data[0] : 0, data.size() * sizeof(PodType)
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
        , detail::buffer_debug_check<
            typename std::vector<PodType, Allocator>::const_iterator
          >(data.begin())
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
        ));
}


template <typename PodType, typename Allocator>
inline const_buffers_1 buffer(
    const std::vector<PodType, Allocator>& data, std::size_t max_size_in_bytes)
{
  return const_buffers_1(
      const_buffer(data.size() ? &data[0] : 0,
        data.size() * sizeof(PodType) < max_size_in_bytes
        ? data.size() * sizeof(PodType) : max_size_in_bytes
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
        , detail::buffer_debug_check<
            typename std::vector<PodType, Allocator>::const_iterator
          >(data.begin())
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
        ));
}


template <typename Elem, typename Traits, typename Allocator>
inline const_buffers_1 buffer(
    const std::basic_string<Elem, Traits, Allocator>& data)
{
  return const_buffers_1(const_buffer(data.data(), data.size() * sizeof(Elem)
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
        , detail::buffer_debug_check<
            typename std::basic_string<Elem, Traits, Allocator>::const_iterator
          >(data.begin())
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
        ));
}


template <typename Elem, typename Traits, typename Allocator>
inline const_buffers_1 buffer(
    const std::basic_string<Elem, Traits, Allocator>& data,
    std::size_t max_size_in_bytes)
{
  return const_buffers_1(
      const_buffer(data.data(),
        data.size() * sizeof(Elem) < max_size_in_bytes
        ? data.size() * sizeof(Elem) : max_size_in_bytes
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
        , detail::buffer_debug_check<
            typename std::basic_string<Elem, Traits, Allocator>::const_iterator
          >(data.begin())
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
        ));
}



inline std::size_t buffer_copy(const mutable_buffer& target,
    const const_buffer& source)
{
  using namespace std; // For memcpy.
  std::size_t target_size = buffer_size(target);
  std::size_t source_size = buffer_size(source);
  std::size_t n = target_size < source_size ? target_size : source_size;
  memcpy(buffer_cast<void*>(target), buffer_cast<const void*>(source), n);
  return n;
}


inline std::size_t buffer_copy(const mutable_buffer& target,
    const const_buffers_1& source)
{
  return buffer_copy(target, static_cast<const const_buffer&>(source));
}


inline std::size_t buffer_copy(const mutable_buffer& target,
    const mutable_buffer& source)
{
  return buffer_copy(target, const_buffer(source));
}


inline std::size_t buffer_copy(const mutable_buffer& target,
    const mutable_buffers_1& source)
{
  return buffer_copy(target, const_buffer(source));
}


template <typename ConstBufferSequence>
std::size_t buffer_copy(const mutable_buffer& target,
    const ConstBufferSequence& source)
{
  std::size_t total_bytes_copied = 0;

  typename ConstBufferSequence::const_iterator source_iter = source.begin();
  typename ConstBufferSequence::const_iterator source_end = source.end();

  for (mutable_buffer target_buffer(target);
      buffer_size(target_buffer) && source_iter != source_end; ++source_iter)
  {
    const_buffer source_buffer(*source_iter);
    std::size_t bytes_copied = buffer_copy(target_buffer, source_buffer);
    total_bytes_copied += bytes_copied;
    target_buffer = target_buffer + bytes_copied;
  }

  return total_bytes_copied;
}


inline std::size_t buffer_copy(const mutable_buffers_1& target,
    const const_buffer& source)
{
  return buffer_copy(static_cast<const mutable_buffer&>(target), source);
}


inline std::size_t buffer_copy(const mutable_buffers_1& target,
    const const_buffers_1& source)
{
  return buffer_copy(static_cast<const mutable_buffer&>(target),
      static_cast<const const_buffer&>(source));
}


inline std::size_t buffer_copy(const mutable_buffers_1& target,
    const mutable_buffer& source)
{
  return buffer_copy(static_cast<const mutable_buffer&>(target),
      const_buffer(source));
}


inline std::size_t buffer_copy(const mutable_buffers_1& target,
    const mutable_buffers_1& source)
{
  return buffer_copy(static_cast<const mutable_buffer&>(target),
      const_buffer(source));
}


template <typename ConstBufferSequence>
inline std::size_t buffer_copy(const mutable_buffers_1& target,
    const ConstBufferSequence& source)
{
  return buffer_copy(static_cast<const mutable_buffer&>(target), source);
}


template <typename MutableBufferSequence>
std::size_t buffer_copy(const MutableBufferSequence& target,
    const const_buffer& source)
{
  std::size_t total_bytes_copied = 0;

  typename MutableBufferSequence::const_iterator target_iter = target.begin();
  typename MutableBufferSequence::const_iterator target_end = target.end();

  for (const_buffer source_buffer(source);
      buffer_size(source_buffer) && target_iter != target_end; ++target_iter)
  {
    mutable_buffer target_buffer(*target_iter);
    std::size_t bytes_copied = buffer_copy(target_buffer, source_buffer);
    total_bytes_copied += bytes_copied;
    source_buffer = source_buffer + bytes_copied;
  }

  return total_bytes_copied;
}


template <typename MutableBufferSequence>
inline std::size_t buffer_copy(const MutableBufferSequence& target,
    const const_buffers_1& source)
{
  return buffer_copy(target, static_cast<const const_buffer&>(source));
}


template <typename MutableBufferSequence>
inline std::size_t buffer_copy(const MutableBufferSequence& target,
    const mutable_buffer& source)
{
  return buffer_copy(target, const_buffer(source));
}


template <typename MutableBufferSequence>
inline std::size_t buffer_copy(const MutableBufferSequence& target,
    const mutable_buffers_1& source)
{
  return buffer_copy(target, const_buffer(source));
}


template <typename MutableBufferSequence, typename ConstBufferSequence>
std::size_t buffer_copy(const MutableBufferSequence& target,
    const ConstBufferSequence& source)
{
  std::size_t total_bytes_copied = 0;

  typename MutableBufferSequence::const_iterator target_iter = target.begin();
  typename MutableBufferSequence::const_iterator target_end = target.end();
  std::size_t target_buffer_offset = 0;

  typename ConstBufferSequence::const_iterator source_iter = source.begin();
  typename ConstBufferSequence::const_iterator source_end = source.end();
  std::size_t source_buffer_offset = 0;

  while (target_iter != target_end && source_iter != source_end)
  {
    mutable_buffer target_buffer =
      mutable_buffer(*target_iter) + target_buffer_offset;

    const_buffer source_buffer =
      const_buffer(*source_iter) + source_buffer_offset;

    std::size_t bytes_copied = buffer_copy(target_buffer, source_buffer);
    total_bytes_copied += bytes_copied;

    if (bytes_copied == buffer_size(target_buffer))
    {
      ++target_iter;
      target_buffer_offset = 0;
    }
    else
      target_buffer_offset += bytes_copied;

    if (bytes_copied == buffer_size(source_buffer))
    {
      ++source_iter;
      source_buffer_offset = 0;
    }
    else
      source_buffer_offset += bytes_copied;
  }

  return total_bytes_copied;
}


inline std::size_t buffer_copy(const mutable_buffer& target,
    const const_buffer& source, std::size_t max_bytes_to_copy)
{
  return buffer_copy(buffer(target, max_bytes_to_copy), source);
}


inline std::size_t buffer_copy(const mutable_buffer& target,
    const const_buffers_1& source, std::size_t max_bytes_to_copy)
{
  return buffer_copy(buffer(target, max_bytes_to_copy), source);
}


inline std::size_t buffer_copy(const mutable_buffer& target,
    const mutable_buffer& source, std::size_t max_bytes_to_copy)
{
  return buffer_copy(buffer(target, max_bytes_to_copy), source);
}


inline std::size_t buffer_copy(const mutable_buffer& target,
    const mutable_buffers_1& source, std::size_t max_bytes_to_copy)
{
  return buffer_copy(buffer(target, max_bytes_to_copy), source);
}


template <typename ConstBufferSequence>
inline std::size_t buffer_copy(const mutable_buffer& target,
    const ConstBufferSequence& source, std::size_t max_bytes_to_copy)
{
  return buffer_copy(buffer(target, max_bytes_to_copy), source);
}


inline std::size_t buffer_copy(const mutable_buffers_1& target,
    const const_buffer& source, std::size_t max_bytes_to_copy)
{
  return buffer_copy(buffer(target, max_bytes_to_copy), source);
}


inline std::size_t buffer_copy(const mutable_buffers_1& target,
    const const_buffers_1& source, std::size_t max_bytes_to_copy)
{
  return buffer_copy(buffer(target, max_bytes_to_copy), source);
}


inline std::size_t buffer_copy(const mutable_buffers_1& target,
    const mutable_buffer& source, std::size_t max_bytes_to_copy)
{
  return buffer_copy(buffer(target, max_bytes_to_copy), source);
}


inline std::size_t buffer_copy(const mutable_buffers_1& target,
    const mutable_buffers_1& source, std::size_t max_bytes_to_copy)
{
  return buffer_copy(buffer(target, max_bytes_to_copy), source);
}


template <typename ConstBufferSequence>
inline std::size_t buffer_copy(const mutable_buffers_1& target,
    const ConstBufferSequence& source, std::size_t max_bytes_to_copy)
{
  return buffer_copy(buffer(target, max_bytes_to_copy), source);
}


template <typename MutableBufferSequence>
inline std::size_t buffer_copy(const MutableBufferSequence& target,
    const const_buffer& source, std::size_t max_bytes_to_copy)
{
  return buffer_copy(target, buffer(source, max_bytes_to_copy));
}


template <typename MutableBufferSequence>
inline std::size_t buffer_copy(const MutableBufferSequence& target,
    const const_buffers_1& source, std::size_t max_bytes_to_copy)
{
  return buffer_copy(target, buffer(source, max_bytes_to_copy));
}


template <typename MutableBufferSequence>
inline std::size_t buffer_copy(const MutableBufferSequence& target,
    const mutable_buffer& source, std::size_t max_bytes_to_copy)
{
  return buffer_copy(target, buffer(source, max_bytes_to_copy));
}


template <typename MutableBufferSequence>
inline std::size_t buffer_copy(const MutableBufferSequence& target,
    const mutable_buffers_1& source, std::size_t max_bytes_to_copy)
{
  return buffer_copy(target, buffer(source, max_bytes_to_copy));
}


template <typename MutableBufferSequence, typename ConstBufferSequence>
std::size_t buffer_copy(const MutableBufferSequence& target,
    const ConstBufferSequence& source, std::size_t max_bytes_to_copy)
{
  std::size_t total_bytes_copied = 0;

  typename MutableBufferSequence::const_iterator target_iter = target.begin();
  typename MutableBufferSequence::const_iterator target_end = target.end();
  std::size_t target_buffer_offset = 0;

  typename ConstBufferSequence::const_iterator source_iter = source.begin();
  typename ConstBufferSequence::const_iterator source_end = source.end();
  std::size_t source_buffer_offset = 0;

  while (total_bytes_copied != max_bytes_to_copy
      && target_iter != target_end && source_iter != source_end)
  {
    mutable_buffer target_buffer =
      mutable_buffer(*target_iter) + target_buffer_offset;

    const_buffer source_buffer =
      const_buffer(*source_iter) + source_buffer_offset;

    std::size_t bytes_copied = buffer_copy(target_buffer,
        source_buffer, max_bytes_to_copy - total_bytes_copied);
    total_bytes_copied += bytes_copied;

    if (bytes_copied == buffer_size(target_buffer))
    {
      ++target_iter;
      target_buffer_offset = 0;
    }
    else
      target_buffer_offset += bytes_copied;

    if (bytes_copied == buffer_size(source_buffer))
    {
      ++source_iter;
      source_buffer_offset = 0;
    }
    else
      source_buffer_offset += bytes_copied;
  }

  return total_bytes_copied;
}

} // namespace asio

#include "asio/detail/pop_options.hpp"

#endif // ASIO_BUFFER_HPP