140 lines
4.4 KiB
Plaintext
140 lines
4.4 KiB
Plaintext
//-----------------------------------------------------------------------------
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// boost detail/templated_streams.hpp header file
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// See http://www.boost.org for updates, documentation, and revision history.
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//-----------------------------------------------------------------------------
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//
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// Copyright (c) 2013 John Maddock, Antony Polukhin
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//
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//
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// Distributed under the Boost Software License, Version 1.0. (See
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// accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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#ifndef BOOST_DETAIL_BASIC_POINTERBUF_HPP
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#define BOOST_DETAIL_BASIC_POINTERBUF_HPP
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// MS compatible compilers support #pragma once
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#if defined(_MSC_VER)
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# pragma once
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#endif
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#include "boost/config.hpp"
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#include <streambuf>
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namespace boost { namespace detail {
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//
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// class basic_pointerbuf:
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// acts as a stream buffer which wraps around a pair of pointers:
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//
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template <class charT, class BufferT >
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class basic_pointerbuf : public BufferT {
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protected:
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typedef BufferT base_type;
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typedef basic_pointerbuf<charT, BufferT> this_type;
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typedef typename base_type::int_type int_type;
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typedef typename base_type::char_type char_type;
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typedef typename base_type::pos_type pos_type;
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typedef ::std::streamsize streamsize;
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typedef typename base_type::off_type off_type;
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public:
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basic_pointerbuf() : base_type() { setbuf(0, 0); }
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const charT* getnext() { return this->gptr(); }
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#ifndef BOOST_NO_USING_TEMPLATE
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using base_type::pptr;
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using base_type::pbase;
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#else
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charT* pptr() const { return base_type::pptr(); }
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charT* pbase() const { return base_type::pbase(); }
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#endif
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protected:
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// VC mistakenly assumes that `setbuf` and other functions are not referenced.
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// Marking those functions with `inline` suppresses the warnings.
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// There must be no harm from marking virtual functions as inline: inline virtual
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// call can be inlined ONLY when the compiler knows the "exact class".
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inline base_type* setbuf(char_type* s, streamsize n);
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inline typename this_type::pos_type seekpos(pos_type sp, ::std::ios_base::openmode which);
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inline typename this_type::pos_type seekoff(off_type off, ::std::ios_base::seekdir way, ::std::ios_base::openmode which);
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private:
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basic_pointerbuf& operator=(const basic_pointerbuf&);
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basic_pointerbuf(const basic_pointerbuf&);
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};
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template<class charT, class BufferT>
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BufferT*
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basic_pointerbuf<charT, BufferT>::setbuf(char_type* s, streamsize n)
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{
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this->setg(s, s, s + n);
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return this;
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}
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template<class charT, class BufferT>
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typename basic_pointerbuf<charT, BufferT>::pos_type
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basic_pointerbuf<charT, BufferT>::seekoff(off_type off, ::std::ios_base::seekdir way, ::std::ios_base::openmode which)
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{
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typedef typename boost::int_t<sizeof(way) * CHAR_BIT>::least cast_type;
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if(which & ::std::ios_base::out)
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return pos_type(off_type(-1));
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std::ptrdiff_t size = this->egptr() - this->eback();
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std::ptrdiff_t pos = this->gptr() - this->eback();
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charT* g = this->eback();
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switch(static_cast<cast_type>(way))
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{
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case ::std::ios_base::beg:
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if((off < 0) || (off > size))
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return pos_type(off_type(-1));
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else
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this->setg(g, g + off, g + size);
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break;
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case ::std::ios_base::end:
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if((off < 0) || (off > size))
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return pos_type(off_type(-1));
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else
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this->setg(g, g + size - off, g + size);
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break;
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case ::std::ios_base::cur:
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{
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std::ptrdiff_t newpos = static_cast<std::ptrdiff_t>(pos + off);
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if((newpos < 0) || (newpos > size))
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return pos_type(off_type(-1));
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else
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this->setg(g, g + newpos, g + size);
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break;
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}
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default: ;
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}
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#ifdef BOOST_MSVC
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#pragma warning(push)
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#pragma warning(disable:4244)
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#endif
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return static_cast<pos_type>(this->gptr() - this->eback());
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#ifdef BOOST_MSVC
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#pragma warning(pop)
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#endif
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}
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template<class charT, class BufferT>
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typename basic_pointerbuf<charT, BufferT>::pos_type
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basic_pointerbuf<charT, BufferT>::seekpos(pos_type sp, ::std::ios_base::openmode which)
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{
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if(which & ::std::ios_base::out)
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return pos_type(off_type(-1));
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off_type size = static_cast<off_type>(this->egptr() - this->eback());
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charT* g = this->eback();
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if(off_type(sp) <= size)
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{
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this->setg(g, g + off_type(sp), g + size);
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}
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return pos_type(off_type(-1));
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}
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}} // namespace boost::detail
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#endif // BOOST_DETAIL_BASIC_POINTERBUF_HPP
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