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//-----------------------------------------------------------------------------
// boost detail/templated_streams.hpp header file
// See http://www.boost.org for updates, documentation, and revision history.
//-----------------------------------------------------------------------------
//
// Copyright (c) 2013 John Maddock, Antony Polukhin
//
//
// 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 BOOST_DETAIL_BASIC_POINTERBUF_HPP
#define BOOST_DETAIL_BASIC_POINTERBUF_HPP
// MS compatible compilers support #pragma once
#if defined(_MSC_VER)
# pragma once
#endif
#include "boost/config.hpp"
#include <streambuf>
namespace boost { namespace detail {
//
// class basic_pointerbuf:
// acts as a stream buffer which wraps around a pair of pointers:
//
template <class charT, class BufferT >
class basic_pointerbuf : public BufferT {
protected:
typedef BufferT base_type;
typedef basic_pointerbuf<charT, BufferT> this_type;
typedef typename base_type::int_type int_type;
typedef typename base_type::char_type char_type;
typedef typename base_type::pos_type pos_type;
typedef ::std::streamsize streamsize;
typedef typename base_type::off_type off_type;
public:
basic_pointerbuf() : base_type() { setbuf(0, 0); }
const charT* getnext() { return this->gptr(); }
#ifndef BOOST_NO_USING_TEMPLATE
using base_type::pptr;
using base_type::pbase;
#else
charT* pptr() const { return base_type::pptr(); }
charT* pbase() const { return base_type::pbase(); }
#endif
protected:
// VC mistakenly assumes that `setbuf` and other functions are not referenced.
// Marking those functions with `inline` suppresses the warnings.
// There must be no harm from marking virtual functions as inline: inline virtual
// call can be inlined ONLY when the compiler knows the "exact class".
inline base_type* setbuf(char_type* s, streamsize n);
inline typename this_type::pos_type seekpos(pos_type sp, ::std::ios_base::openmode which);
inline typename this_type::pos_type seekoff(off_type off, ::std::ios_base::seekdir way, ::std::ios_base::openmode which);
private:
basic_pointerbuf& operator=(const basic_pointerbuf&);
basic_pointerbuf(const basic_pointerbuf&);
};
template<class charT, class BufferT>
BufferT*
basic_pointerbuf<charT, BufferT>::setbuf(char_type* s, streamsize n)
{
this->setg(s, s, s + n);
return this;
}
template<class charT, class BufferT>
typename basic_pointerbuf<charT, BufferT>::pos_type
basic_pointerbuf<charT, BufferT>::seekoff(off_type off, ::std::ios_base::seekdir way, ::std::ios_base::openmode which)
{
typedef typename boost::int_t<sizeof(way) * CHAR_BIT>::least cast_type;
if(which & ::std::ios_base::out)
return pos_type(off_type(-1));
std::ptrdiff_t size = this->egptr() - this->eback();
std::ptrdiff_t pos = this->gptr() - this->eback();
charT* g = this->eback();
switch(static_cast<cast_type>(way))
{
case ::std::ios_base::beg:
if((off < 0) || (off > size))
return pos_type(off_type(-1));
else
this->setg(g, g + off, g + size);
break;
case ::std::ios_base::end:
if((off < 0) || (off > size))
return pos_type(off_type(-1));
else
this->setg(g, g + size - off, g + size);
break;
case ::std::ios_base::cur:
{
std::ptrdiff_t newpos = static_cast<std::ptrdiff_t>(pos + off);
if((newpos < 0) || (newpos > size))
return pos_type(off_type(-1));
else
this->setg(g, g + newpos, g + size);
break;
}
default: ;
}
#ifdef BOOST_MSVC
#pragma warning(push)
#pragma warning(disable:4244)
#endif
return static_cast<pos_type>(this->gptr() - this->eback());
#ifdef BOOST_MSVC
#pragma warning(pop)
#endif
}
template<class charT, class BufferT>
typename basic_pointerbuf<charT, BufferT>::pos_type
basic_pointerbuf<charT, BufferT>::seekpos(pos_type sp, ::std::ios_base::openmode which)
{
if(which & ::std::ios_base::out)
return pos_type(off_type(-1));
off_type size = static_cast<off_type>(this->egptr() - this->eback());
charT* g = this->eback();
if(off_type(sp) <= size)
{
this->setg(g, g + off_type(sp), g + size);
}
return pos_type(off_type(-1));
}
}} // namespace boost::detail
#endif // BOOST_DETAIL_BASIC_POINTERBUF_HPP
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