// Streambuf iterators // Copyright (C) 1997-2020 Free Software Foundation, Inc. // // This file is part of the GNU ISO C++ Library. This library is free // software; you can redistribute it and/or modify it under the // terms of the GNU General Public License as published by the // Free Software Foundation; either version 3, or (at your option) // any later version. // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // Under Section 7 of GPL version 3, you are granted additional // permissions described in the GCC Runtime Library Exception, version // 3.1, as published by the Free Software Foundation. // You should have received a copy of the GNU General Public License and // a copy of the GCC Runtime Library Exception along with this program; // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see // <http://www.gnu.org/licenses/>. /** @file bits/streambuf_iterator.h * This is an internal header file, included by other library headers. * Do not attempt to use it directly. @headername{iterator} */ #ifndef _STREAMBUF_ITERATOR_H #define _STREAMBUF_ITERATOR_H 1 #pragma GCC system_header #include <streambuf> #include <debug/debug.h> namespace std _GLIBCXX_VISIBILITY(default) { _GLIBCXX_BEGIN_NAMESPACE_VERSION /** * @addtogroup iterators * @{ */ // 24.5.3 Template class istreambuf_iterator /// Provides input iterator semantics for streambufs. template<typename _CharT, typename _Traits> class istreambuf_iterator : public iterator<input_iterator_tag, _CharT, typename _Traits::off_type, _CharT*, _CharT> { public: // Types: //@{ /// Public typedefs #if __cplusplus < 201103L typedef _CharT& reference; // Changed to _CharT by LWG 445 #elif __cplusplus > 201703L // _GLIBCXX_RESOLVE_LIB_DEFECTS // 3188. istreambuf_iterator::pointer should not be unspecified using pointer = void; #endif typedef _CharT char_type; typedef _Traits traits_type; typedef typename _Traits::int_type int_type; typedef basic_streambuf<_CharT, _Traits> streambuf_type; typedef basic_istream<_CharT, _Traits> istream_type; //@} template<typename _CharT2> friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value, ostreambuf_iterator<_CharT2> >::__type copy(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>, ostreambuf_iterator<_CharT2>); template<bool _IsMove, typename _CharT2> friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value, _CharT2*>::__type __copy_move_a2(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>, _CharT2*); #if __cplusplus >= 201103L template<typename _CharT2, typename _Size> friend __enable_if_t<__is_char<_CharT2>::__value, _CharT2*> __copy_n_a(istreambuf_iterator<_CharT2>, _Size, _CharT2*); #endif template<typename _CharT2> friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value, istreambuf_iterator<_CharT2> >::__type find(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>, const _CharT2&); template<typename _CharT2, typename _Distance> friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value, void>::__type advance(istreambuf_iterator<_CharT2>&, _Distance); private: // 24.5.3 istreambuf_iterator // p 1 // If the end of stream is reached (streambuf_type::sgetc() // returns traits_type::eof()), the iterator becomes equal to // the "end of stream" iterator value. // NB: This implementation assumes the "end of stream" value // is EOF, or -1. mutable streambuf_type* _M_sbuf; int_type _M_c; public: /// Construct end of input stream iterator. _GLIBCXX_CONSTEXPR istreambuf_iterator() _GLIBCXX_USE_NOEXCEPT : _M_sbuf(0), _M_c(traits_type::eof()) { } #if __cplusplus > 201703L && __cpp_lib_concepts constexpr istreambuf_iterator(default_sentinel_t) noexcept : istreambuf_iterator() { } #endif #if __cplusplus >= 201103L istreambuf_iterator(const istreambuf_iterator&) noexcept = default; ~istreambuf_iterator() = default; #endif /// Construct start of input stream iterator. istreambuf_iterator(istream_type& __s) _GLIBCXX_USE_NOEXCEPT : _M_sbuf(__s.rdbuf()), _M_c(traits_type::eof()) { } /// Construct start of streambuf iterator. istreambuf_iterator(streambuf_type* __s) _GLIBCXX_USE_NOEXCEPT : _M_sbuf(__s), _M_c(traits_type::eof()) { } #if __cplusplus >= 201103L istreambuf_iterator& operator=(const istreambuf_iterator&) noexcept = default; #endif /// Return the current character pointed to by iterator. This returns /// streambuf.sgetc(). It cannot be assigned. NB: The result of /// operator*() on an end of stream is undefined. char_type operator*() const { int_type __c = _M_get(); #ifdef _GLIBCXX_DEBUG_PEDANTIC // Dereferencing a past-the-end istreambuf_iterator is a // libstdc++ extension __glibcxx_requires_cond(!_S_is_eof(__c), _M_message(__gnu_debug::__msg_deref_istreambuf) ._M_iterator(*this)); #endif return traits_type::to_char_type(__c); } /// Advance the iterator. Calls streambuf.sbumpc(). istreambuf_iterator& operator++() { __glibcxx_requires_cond(_M_sbuf && (!_S_is_eof(_M_c) || !_S_is_eof(_M_sbuf->sgetc())), _M_message(__gnu_debug::__msg_inc_istreambuf) ._M_iterator(*this)); _M_sbuf->sbumpc(); _M_c = traits_type::eof(); return *this; } /// Advance the iterator. Calls streambuf.sbumpc(). istreambuf_iterator operator++(int) { __glibcxx_requires_cond(_M_sbuf && (!_S_is_eof(_M_c) || !_S_is_eof(_M_sbuf->sgetc())), _M_message(__gnu_debug::__msg_inc_istreambuf) ._M_iterator(*this)); istreambuf_iterator __old = *this; __old._M_c = _M_sbuf->sbumpc(); _M_c = traits_type::eof(); return __old; } // _GLIBCXX_RESOLVE_LIB_DEFECTS // 110 istreambuf_iterator::equal not const // NB: there is also number 111 (NAD) relevant to this function. /// Return true both iterators are end or both are not end. bool equal(const istreambuf_iterator& __b) const { return _M_at_eof() == __b._M_at_eof(); } private: int_type _M_get() const { int_type __ret = _M_c; if (_M_sbuf && _S_is_eof(__ret) && _S_is_eof(__ret = _M_sbuf->sgetc())) _M_sbuf = 0; return __ret; } bool _M_at_eof() const { return _S_is_eof(_M_get()); } static bool _S_is_eof(int_type __c) { const int_type __eof = traits_type::eof(); return traits_type::eq_int_type(__c, __eof); } #if __cplusplus > 201703L && __cpp_lib_concepts friend bool operator==(const istreambuf_iterator& __i, default_sentinel_t __s) { return __i._M_at_eof(); } #endif }; template<typename _CharT, typename _Traits> inline bool operator==(const istreambuf_iterator<_CharT, _Traits>& __a, const istreambuf_iterator<_CharT, _Traits>& __b) { return __a.equal(__b); } template<typename _CharT, typename _Traits> inline bool operator!=(const istreambuf_iterator<_CharT, _Traits>& __a, const istreambuf_iterator<_CharT, _Traits>& __b) { return !__a.equal(__b); } /// Provides output iterator semantics for streambufs. template<typename _CharT, typename _Traits> class ostreambuf_iterator : public iterator<output_iterator_tag, void, void, void, void> { public: // Types: //@{ /// Public typedefs #if __cplusplus > 201703L using difference_type = ptrdiff_t; #endif typedef _CharT char_type; typedef _Traits traits_type; typedef basic_streambuf<_CharT, _Traits> streambuf_type; typedef basic_ostream<_CharT, _Traits> ostream_type; //@} template<typename _CharT2> friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value, ostreambuf_iterator<_CharT2> >::__type copy(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>, ostreambuf_iterator<_CharT2>); private: streambuf_type* _M_sbuf; bool _M_failed; public: #if __cplusplus > 201703L constexpr ostreambuf_iterator() noexcept : _M_sbuf(nullptr), _M_failed(true) { } #endif /// Construct output iterator from ostream. ostreambuf_iterator(ostream_type& __s) _GLIBCXX_USE_NOEXCEPT : _M_sbuf(__s.rdbuf()), _M_failed(!_M_sbuf) { } /// Construct output iterator from streambuf. ostreambuf_iterator(streambuf_type* __s) _GLIBCXX_USE_NOEXCEPT : _M_sbuf(__s), _M_failed(!_M_sbuf) { } /// Write character to streambuf. Calls streambuf.sputc(). ostreambuf_iterator& operator=(_CharT __c) { if (!_M_failed && _Traits::eq_int_type(_M_sbuf->sputc(__c), _Traits::eof())) _M_failed = true; return *this; } /// Return *this. ostreambuf_iterator& operator*() { return *this; } /// Return *this. ostreambuf_iterator& operator++(int) { return *this; } /// Return *this. ostreambuf_iterator& operator++() { return *this; } /// Return true if previous operator=() failed. bool failed() const _GLIBCXX_USE_NOEXCEPT { return _M_failed; } ostreambuf_iterator& _M_put(const _CharT* __ws, streamsize __len) { if (__builtin_expect(!_M_failed, true) && __builtin_expect(this->_M_sbuf->sputn(__ws, __len) != __len, false)) _M_failed = true; return *this; } }; // Overloads for streambuf iterators. template<typename _CharT> typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, ostreambuf_iterator<_CharT> >::__type copy(istreambuf_iterator<_CharT> __first, istreambuf_iterator<_CharT> __last, ostreambuf_iterator<_CharT> __result) { if (__first._M_sbuf && !__last._M_sbuf && !__result._M_failed) { bool __ineof; __copy_streambufs_eof(__first._M_sbuf, __result._M_sbuf, __ineof); if (!__ineof) __result._M_failed = true; } return __result; } template<bool _IsMove, typename _CharT> typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, ostreambuf_iterator<_CharT> >::__type __copy_move_a2(_CharT* __first, _CharT* __last, ostreambuf_iterator<_CharT> __result) { const streamsize __num = __last - __first; if (__num > 0) __result._M_put(__first, __num); return __result; } template<bool _IsMove, typename _CharT> typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, ostreambuf_iterator<_CharT> >::__type __copy_move_a2(const _CharT* __first, const _CharT* __last, ostreambuf_iterator<_CharT> __result) { const streamsize __num = __last - __first; if (__num > 0) __result._M_put(__first, __num); return __result; } template<bool _IsMove, typename _CharT> typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, _CharT*>::__type __copy_move_a2(istreambuf_iterator<_CharT> __first, istreambuf_iterator<_CharT> __last, _CharT* __result) { typedef istreambuf_iterator<_CharT> __is_iterator_type; typedef typename __is_iterator_type::traits_type traits_type; typedef typename __is_iterator_type::streambuf_type streambuf_type; typedef typename traits_type::int_type int_type; if (__first._M_sbuf && !__last._M_sbuf) { streambuf_type* __sb = __first._M_sbuf; int_type __c = __sb->sgetc(); while (!traits_type::eq_int_type(__c, traits_type::eof())) { const streamsize __n = __sb->egptr() - __sb->gptr(); if (__n > 1) { traits_type::copy(__result, __sb->gptr(), __n); __sb->__safe_gbump(__n); __result += __n; __c = __sb->underflow(); } else { *__result++ = traits_type::to_char_type(__c); __c = __sb->snextc(); } } } return __result; } #if __cplusplus >= 201103L template<typename _CharT, typename _Size> __enable_if_t<__is_char<_CharT>::__value, _CharT*> __copy_n_a(istreambuf_iterator<_CharT> __it, _Size __n, _CharT* __result) { if (__n == 0) return __result; __glibcxx_requires_cond(__it._M_sbuf, _M_message(__gnu_debug::__msg_inc_istreambuf) ._M_iterator(__it)); _CharT* __beg = __result; __result += __it._M_sbuf->sgetn(__beg, __n); __glibcxx_requires_cond(__result - __beg == __n, _M_message(__gnu_debug::__msg_inc_istreambuf) ._M_iterator(__it)); return __result; } #endif // C++11 template<typename _CharT> typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, istreambuf_iterator<_CharT> >::__type find(istreambuf_iterator<_CharT> __first, istreambuf_iterator<_CharT> __last, const _CharT& __val) { typedef istreambuf_iterator<_CharT> __is_iterator_type; typedef typename __is_iterator_type::traits_type traits_type; typedef typename __is_iterator_type::streambuf_type streambuf_type; typedef typename traits_type::int_type int_type; const int_type __eof = traits_type::eof(); if (__first._M_sbuf && !__last._M_sbuf) { const int_type __ival = traits_type::to_int_type(__val); streambuf_type* __sb = __first._M_sbuf; int_type __c = __sb->sgetc(); while (!traits_type::eq_int_type(__c, __eof) && !traits_type::eq_int_type(__c, __ival)) { streamsize __n = __sb->egptr() - __sb->gptr(); if (__n > 1) { const _CharT* __p = traits_type::find(__sb->gptr(), __n, __val); if (__p) __n = __p - __sb->gptr(); __sb->__safe_gbump(__n); __c = __sb->sgetc(); } else __c = __sb->snextc(); } __first._M_c = __eof; } return __first; } template<typename _CharT, typename _Distance> typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, void>::__type advance(istreambuf_iterator<_CharT>& __i, _Distance __n) { if (__n == 0) return; __glibcxx_assert(__n > 0); __glibcxx_requires_cond(!__i._M_at_eof(), _M_message(__gnu_debug::__msg_inc_istreambuf) ._M_iterator(__i)); typedef istreambuf_iterator<_CharT> __is_iterator_type; typedef typename __is_iterator_type::traits_type traits_type; typedef typename __is_iterator_type::streambuf_type streambuf_type; typedef typename traits_type::int_type int_type; const int_type __eof = traits_type::eof(); streambuf_type* __sb = __i._M_sbuf; while (__n > 0) { streamsize __size = __sb->egptr() - __sb->gptr(); if (__size > __n) { __sb->__safe_gbump(__n); break; } __sb->__safe_gbump(__size); __n -= __size; if (traits_type::eq_int_type(__sb->underflow(), __eof)) { __glibcxx_requires_cond(__n == 0, _M_message(__gnu_debug::__msg_inc_istreambuf) ._M_iterator(__i)); break; } } __i._M_c = __eof; } // @} group iterators _GLIBCXX_END_NAMESPACE_VERSION } // namespace #endif