140 lines
4.4 KiB
C++
140 lines
4.4 KiB
C++
//-----------------------------------------------------------------------------
|
|
// 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
|
|
|