| 1 | // ---------------------------------------------------------------------------- |
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| 2 | // alt_sstream_impl.hpp : alternative stringstream, templates implementation |
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| 3 | // ---------------------------------------------------------------------------- |
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| 4 | |
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| 5 | // Copyright Samuel Krempp 2003. Use, modification, and distribution are |
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| 6 | // subject to the Boost Software License, Version 1.0. (See accompanying |
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| 7 | // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
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| 8 | |
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| 9 | // See http://www.boost.org/libs/format for library home page |
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| 10 | |
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| 11 | // ---------------------------------------------------------------------------- |
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| 12 | |
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| 13 | #ifndef BOOST_SK_ALT_SSTREAM_IMPL_HPP |
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| 14 | #define BOOST_SK_ALT_SSTREAM_IMPL_HPP |
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| 15 | |
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| 16 | namespace boost { |
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| 17 | namespace io { |
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| 18 | // --- Implementation ------------------------------------------------------// |
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| 19 | |
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| 20 | template<class Ch, class Tr, class Alloc> |
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| 21 | void basic_altstringbuf<Ch, Tr, Alloc>:: |
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| 22 | clear_buffer () { |
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| 23 | const Ch * p = pptr(); |
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| 24 | const Ch * b = pbase(); |
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| 25 | if(p != NULL && p != b) { |
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| 26 | seekpos(0, ::std::ios_base::out); |
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| 27 | } |
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| 28 | p = gptr(); |
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| 29 | b = eback(); |
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| 30 | if(p != NULL && p != b) { |
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| 31 | seekpos(0, ::std::ios_base::in); |
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| 32 | } |
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| 33 | } |
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| 34 | |
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| 35 | template<class Ch, class Tr, class Alloc> |
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| 36 | void basic_altstringbuf<Ch, Tr, Alloc>:: |
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| 37 | str (const string_type& s) { |
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| 38 | size_type sz=s.size(); |
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| 39 | if(sz != 0 && mode_ & (::std::ios_base::in | ::std::ios_base::out) ) { |
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| 40 | Ch *new_ptr = alloc_.allocate(sz, is_allocated_? eback() : 0); |
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| 41 | // if this didnt throw, we're safe, update the buffer |
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| 42 | dealloc(); |
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| 43 | sz = s.copy(new_ptr, sz); |
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| 44 | putend_ = new_ptr + sz; |
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| 45 | if(mode_ & ::std::ios_base::in) |
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| 46 | streambuf_t::setg(new_ptr, new_ptr, new_ptr + sz); |
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| 47 | if(mode_ & ::std::ios_base::out) { |
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| 48 | streambuf_t::setp(new_ptr, new_ptr + sz); |
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| 49 | if(mode_ & (::std::ios_base::app | ::std::ios_base::ate)) |
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| 50 | streambuf_t::pbump(static_cast<int>(sz)); |
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| 51 | if(gptr() == NULL) |
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| 52 | streambuf_t::setg(new_ptr, NULL, new_ptr); |
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| 53 | } |
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| 54 | is_allocated_ = true; |
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| 55 | } |
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| 56 | else |
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| 57 | dealloc(); |
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| 58 | } |
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| 59 | template<class Ch, class Tr, class Alloc> |
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| 60 | Ch* basic_altstringbuf<Ch, Tr, Alloc>:: |
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| 61 | begin () const { |
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| 62 | if(mode_ & ::std::ios_base::out && pptr() != NULL) |
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| 63 | return pbase(); |
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| 64 | else if(mode_ & ::std::ios_base::in && gptr() != NULL) |
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| 65 | return eback(); |
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| 66 | return NULL; |
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| 67 | } |
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| 68 | |
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| 69 | template<class Ch, class Tr, class Alloc> |
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| 70 | typename std::basic_string<Ch,Tr,Alloc>::size_type |
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| 71 | basic_altstringbuf<Ch, Tr, Alloc>:: |
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| 72 | size () const { |
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| 73 | if(mode_ & ::std::ios_base::out && pptr()) |
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| 74 | return static_cast<size_type>(pend() - pbase()); |
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| 75 | else if(mode_ & ::std::ios_base::in && gptr()) |
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| 76 | return static_cast<size_type>(egptr() - eback()); |
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| 77 | else |
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| 78 | return 0; |
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| 79 | } |
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| 80 | |
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| 81 | template<class Ch, class Tr, class Alloc> |
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| 82 | typename std::basic_string<Ch,Tr,Alloc>::size_type |
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| 83 | basic_altstringbuf<Ch, Tr, Alloc>:: |
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| 84 | cur_size () const { |
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| 85 | if(mode_ & ::std::ios_base::out && pptr()) |
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| 86 | return static_cast<streamsize>( pptr() - pbase()); |
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| 87 | else if(mode_ & ::std::ios_base::in && gptr()) |
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| 88 | return static_cast<streamsize>( gptr() - eback()); |
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| 89 | else |
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| 90 | return 0; |
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| 91 | } |
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| 92 | |
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| 93 | template<class Ch, class Tr, class Alloc> |
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| 94 | typename basic_altstringbuf<Ch, Tr, Alloc>::pos_type |
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| 95 | basic_altstringbuf<Ch, Tr, Alloc>:: |
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| 96 | seekoff (off_type off, ::std::ios_base::seekdir way, ::std::ios_base::openmode which) { |
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| 97 | if(pptr() != NULL && putend_ < pptr()) |
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| 98 | putend_ = pptr(); |
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| 99 | if(which & ::std::ios_base::in && gptr() != NULL) { |
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| 100 | // get area |
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| 101 | if(way == ::std::ios_base::end) |
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| 102 | off += static_cast<off_type>(putend_ - gptr()); |
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| 103 | else if(way == ::std::ios_base::beg) |
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| 104 | off += static_cast<off_type>(eback() - gptr()); |
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| 105 | else if(way != ::std::ios_base::cur || (which & ::std::ios_base::out) ) |
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| 106 | // (altering in&out is only supported if way is beg or end, not cur) |
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| 107 | return pos_type(off_type(-1)); |
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| 108 | if(eback() <= off+gptr() && off+gptr() <= putend_ ) { |
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| 109 | // set gptr |
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| 110 | streambuf_t::gbump(off); |
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| 111 | if(which & ::std::ios_base::out && pptr() != NULL) |
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| 112 | // update pptr to match gptr |
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| 113 | streambuf_t::pbump(static_cast<int>(gptr()-pptr())); |
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| 114 | } |
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| 115 | else |
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| 116 | off = off_type(-1); |
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| 117 | } |
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| 118 | else if(which & ::std::ios_base::out && pptr() != NULL) { |
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| 119 | // put area |
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| 120 | if(way == ::std::ios_base::end) |
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| 121 | off += static_cast<off_type>(putend_ - pptr()); |
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| 122 | else if(way == ::std::ios_base::beg) |
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| 123 | off += static_cast<off_type>(pbase() - pptr()); |
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| 124 | else if(way != ::std::ios_base::beg) |
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| 125 | return pos_type(off_type(-1)); |
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| 126 | if(pbase() <= off+pptr() && off+pptr() <= putend_) |
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| 127 | // set pptr |
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| 128 | streambuf_t::pbump(off); |
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| 129 | else |
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| 130 | off = off_type(-1); |
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| 131 | } |
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| 132 | else // neither in nor out |
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| 133 | off = off_type(-1); |
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| 134 | return (pos_type(off)); |
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| 135 | } |
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| 136 | //- end seekoff(..) |
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| 137 | |
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| 138 | |
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| 139 | template<class Ch, class Tr, class Alloc> |
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| 140 | typename basic_altstringbuf<Ch, Tr, Alloc>::pos_type |
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| 141 | basic_altstringbuf<Ch, Tr, Alloc>:: |
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| 142 | seekpos (pos_type pos, ::std::ios_base::openmode which) { |
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| 143 | off_type off = off_type(pos); // operation guaranteed by §27.4.3.2 table 88 |
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| 144 | if(pptr() != NULL && putend_ < pptr()) |
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| 145 | putend_ = pptr(); |
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| 146 | if(off != off_type(-1)) { |
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| 147 | if(which & ::std::ios_base::in && gptr() != NULL) { |
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| 148 | // get area |
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| 149 | if(0 <= off && off <= putend_ - eback()) { |
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| 150 | streambuf_t::gbump(static_cast<int>(eback() - gptr() + off)); |
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| 151 | if(which & ::std::ios_base::out && pptr() != NULL) { |
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| 152 | // update pptr to match gptr |
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| 153 | streambuf_t::pbump(static_cast<int>(gptr()-pptr())); |
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| 154 | } |
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| 155 | } |
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| 156 | else |
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| 157 | off = off_type(-1); |
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| 158 | } |
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| 159 | else if(which & ::std::ios_base::out && pptr() != NULL) { |
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| 160 | // put area |
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| 161 | if(0 <= off && off <= putend_ - eback()) |
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| 162 | streambuf_t::pbump(static_cast<int>(eback() - pptr() + off)); |
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| 163 | else |
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| 164 | off = off_type(-1); |
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| 165 | } |
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| 166 | else // neither in nor out |
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| 167 | off = off_type(-1); |
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| 168 | return (pos_type(off)); |
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| 169 | } |
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| 170 | else { |
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| 171 | BOOST_ASSERT(0); // §27.4.3.2 allows undefined-behaviour here |
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| 172 | return pos_type(off_type(-1)); |
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| 173 | } |
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| 174 | } |
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| 175 | // -end seekpos(..) |
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| 176 | |
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| 177 | |
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| 178 | template<class Ch, class Tr, class Alloc> |
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| 179 | typename basic_altstringbuf<Ch, Tr, Alloc>::int_type |
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| 180 | basic_altstringbuf<Ch, Tr, Alloc>:: |
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| 181 | underflow () { |
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| 182 | if(gptr() == NULL) // no get area -> nothing to get. |
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| 183 | return (compat_traits_type::eof()); |
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| 184 | else if(gptr() < egptr()) // ok, in buffer |
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| 185 | return (compat_traits_type::to_int_type(*gptr())); |
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| 186 | else if(mode_ & ::std::ios_base::in && pptr() != NULL |
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| 187 | && (gptr() < pptr() || gptr() < putend_) ) |
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| 188 | { // expand get area |
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| 189 | if(putend_ < pptr()) |
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| 190 | putend_ = pptr(); // remember pptr reached this far |
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| 191 | streambuf_t::setg(eback(), gptr(), putend_); |
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| 192 | return (compat_traits_type::to_int_type(*gptr())); |
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| 193 | } |
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| 194 | else // couldnt get anything. EOF. |
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| 195 | return (compat_traits_type::eof()); |
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| 196 | } |
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| 197 | // -end underflow(..) |
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| 198 | |
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| 199 | |
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| 200 | template<class Ch, class Tr, class Alloc> |
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| 201 | typename basic_altstringbuf<Ch, Tr, Alloc>::int_type |
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| 202 | basic_altstringbuf<Ch, Tr, Alloc>:: |
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| 203 | pbackfail (int_type meta) { |
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| 204 | if(gptr() != NULL && (eback() < gptr()) |
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| 205 | && (mode_ & (::std::ios_base::out) |
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| 206 | || compat_traits_type::eq_int_type(compat_traits_type::eof(), meta) |
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| 207 | || compat_traits_type::eq(compat_traits_type::to_char_type(meta), gptr()[-1]) ) ) { |
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| 208 | streambuf_t::gbump(-1); // back one character |
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| 209 | if(!compat_traits_type::eq_int_type(compat_traits_type::eof(), meta)) |
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| 210 | // put-back meta into get area |
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| 211 | *gptr() = compat_traits_type::to_char_type(meta); |
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| 212 | return (compat_traits_type::not_eof(meta)); |
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| 213 | } |
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| 214 | else |
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| 215 | return (compat_traits_type::eof()); // failed putback |
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| 216 | } |
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| 217 | // -end pbackfail(..) |
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| 218 | |
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| 219 | |
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| 220 | template<class Ch, class Tr, class Alloc> |
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| 221 | typename basic_altstringbuf<Ch, Tr, Alloc>::int_type |
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| 222 | basic_altstringbuf<Ch, Tr, Alloc>:: |
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| 223 | overflow (int_type meta) { |
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| 224 | if(compat_traits_type::eq_int_type(compat_traits_type::eof(), meta)) |
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| 225 | return compat_traits_type::not_eof(meta); // nothing to do |
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| 226 | else if(pptr() != NULL && pptr() < epptr()) { |
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| 227 | streambuf_t::sputc(compat_traits_type::to_char_type(meta)); |
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| 228 | return meta; |
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| 229 | } |
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| 230 | else if(! (mode_ & ::std::ios_base::out)) |
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| 231 | // no write position, and cant make one |
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| 232 | return compat_traits_type::eof(); |
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| 233 | else { // make a write position available |
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| 234 | std::size_t prev_size = pptr() == NULL ? 0 : epptr() - eback(); |
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| 235 | std::size_t new_size = prev_size; |
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| 236 | // exponential growth : size *= 1.5 |
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| 237 | std::size_t add_size = new_size / 2; |
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| 238 | if(add_size < alloc_min) |
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| 239 | add_size = alloc_min; |
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| 240 | Ch * newptr = NULL, *oldptr = eback(); |
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| 241 | |
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| 242 | // make sure adding add_size wont overflow size_t |
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| 243 | while (0 < add_size && ((std::numeric_limits<std::size_t>::max)() |
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| 244 | - add_size < new_size) ) |
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| 245 | add_size /= 2; |
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| 246 | if(0 < add_size) { |
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| 247 | new_size += add_size; |
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| 248 | newptr = alloc_.allocate(new_size, is_allocated_? oldptr : 0); |
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| 249 | } |
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| 250 | |
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| 251 | if(0 < prev_size) |
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| 252 | compat_traits_type::copy(newptr, oldptr, prev_size); |
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| 253 | if(is_allocated_) |
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| 254 | alloc_.deallocate(oldptr, prev_size); |
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| 255 | is_allocated_=true; |
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| 256 | |
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| 257 | if(prev_size == 0) { // first allocation |
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| 258 | putend_ = newptr; |
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| 259 | streambuf_t::setp(newptr, newptr + new_size); |
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| 260 | if(mode_ & ::std::ios_base::in) |
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| 261 | streambuf_t::setg(newptr, newptr, newptr + 1); |
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| 262 | else |
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| 263 | streambuf_t::setg(newptr, 0, newptr); |
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| 264 | } |
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| 265 | else { // update pointers |
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| 266 | putend_ = putend_ - oldptr + newptr; |
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| 267 | int pptr_count = static_cast<int>(pptr()-pbase()); |
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| 268 | int gptr_count = static_cast<int>(gptr()-eback()); |
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| 269 | streambuf_t::setp(pbase() - oldptr + newptr, newptr + new_size); |
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| 270 | streambuf_t::pbump(pptr_count); |
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| 271 | if(mode_ & ::std::ios_base::in) |
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| 272 | streambuf_t::setg(newptr, newptr + gptr_count, pptr() + 1); |
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| 273 | else |
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| 274 | streambuf_t::setg(newptr, 0, newptr); |
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| 275 | } |
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| 276 | streambuf_t::sputc(compat_traits_type::to_char_type(meta)); |
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| 277 | return meta; |
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| 278 | } |
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| 279 | } |
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| 280 | // -end overflow(..) |
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| 281 | |
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| 282 | template<class Ch, class Tr, class Alloc> |
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| 283 | void basic_altstringbuf<Ch, Tr, Alloc>:: dealloc() { |
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| 284 | if(is_allocated_) |
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| 285 | alloc_.deallocate(eback(), (pptr() != NULL ? epptr() : egptr()) - eback()); |
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| 286 | is_allocated_ = false; |
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| 287 | streambuf_t::setg(0, 0, 0); |
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| 288 | streambuf_t::setp(0, 0); |
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| 289 | putend_ = NULL; |
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| 290 | } |
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| 291 | |
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| 292 | }// N.S. io |
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| 293 | } // N.S. boost |
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| 294 | |
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| 295 | #endif // include guard |
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| 296 | |
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