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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() { this_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) BOOST_OVERRIDE;
- inline typename this_type::pos_type seekpos(pos_type sp, ::std::ios_base::openmode which) BOOST_OVERRIDE;
- inline typename this_type::pos_type seekoff(off_type off, ::std::ios_base::seekdir way, ::std::ios_base::openmode which) BOOST_OVERRIDE;
- 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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