v1/__iterator/istreambuf_iterator.h

0001 // -*- C++ -*-
0002 //===----------------------------------------------------------------------===//
0003 //
0004 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0005 // See https://llvm.org/LICENSE.txt for license information.
0006 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0007 //
0008 //===----------------------------------------------------------------------===//
0009
0010 #ifndef _LIBCPP___ITERATOR_ISTREAMBUF_ITERATOR_H
0011 #define _LIBCPP___ITERATOR_ISTREAMBUF_ITERATOR_H
0012
0013 #include <__config>
0014 #include <__fwd/istream.h>
0015 #include <__fwd/streambuf.h>
0016 #include <__iterator/default_sentinel.h>
0017 #include <__iterator/iterator.h>
0018 #include <__iterator/iterator_traits.h>
0019 #include <__string/char_traits.h>
0020 #include <iosfwd>
0021
0022 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
0023 #  pragma GCC system_header
0024 #endif
0025
0026 _LIBCPP_BEGIN_NAMESPACE_STD
0027
0028 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
0029 template <class _CharT, class _Traits>
0030 class _LIBCPP_TEMPLATE_VIS istreambuf_iterator
0031 #if _LIBCPP_STD_VER <= 14 || !defined(_LIBCPP_ABI_NO_ITERATOR_BASES)
0032     : public iterator<input_iterator_tag, _CharT, typename _Traits::off_type, _CharT*, _CharT>
0033 #endif
0034 {
0035   _LIBCPP_SUPPRESS_DEPRECATED_POP
0036
0037 public:
0038   typedef input_iterator_tag iterator_category;
0039   typedef _CharT value_type;
0040   typedef typename _Traits::off_type difference_type;
0041   typedef _CharT* pointer;
0042   typedef _CharT reference;
0043   typedef _CharT char_type;
0044   typedef _Traits traits_type;
0045   typedef typename _Traits::int_type int_type;
0046   typedef basic_streambuf<_CharT, _Traits> streambuf_type;
0047   typedef basic_istream<_CharT, _Traits> istream_type;
0048
0049 private:
0050   mutable streambuf_type* __sbuf_;
0051
0052   class __proxy {
0053     char_type __keep_;
0054     streambuf_type* __sbuf_;
0055     _LIBCPP_HIDE_FROM_ABI explicit __proxy(char_type __c, streambuf_type* __s) : __keep_(__c), __sbuf_(__s) {}
0056     friend class istreambuf_iterator;
0057
0058   public:
0059     _LIBCPP_HIDE_FROM_ABI char_type operator*() const { return __keep_; }
0060   };
0061
0062   _LIBCPP_HIDE_FROM_ABI bool __test_for_eof() const {
0063     if (__sbuf_ && traits_type::eq_int_type(__sbuf_->sgetc(), traits_type::eof()))
0064       __sbuf_ = nullptr;
0065     return __sbuf_ == nullptr;
0066   }
0067
0068 public:
0069   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR istreambuf_iterator() _NOEXCEPT : __sbuf_(nullptr) {}
0070 #if _LIBCPP_STD_VER >= 20
0071   _LIBCPP_HIDE_FROM_ABI constexpr istreambuf_iterator(default_sentinel_t) noexcept : istreambuf_iterator() {}
0072 #endif // _LIBCPP_STD_VER >= 20
0073   _LIBCPP_HIDE_FROM_ABI istreambuf_iterator(istream_type& __s) _NOEXCEPT : __sbuf_(__s.rdbuf()) {}
0074   _LIBCPP_HIDE_FROM_ABI istreambuf_iterator(streambuf_type* __s) _NOEXCEPT : __sbuf_(__s) {}
0075   _LIBCPP_HIDE_FROM_ABI istreambuf_iterator(const __proxy& __p) _NOEXCEPT : __sbuf_(__p.__sbuf_) {}
0076
0077   _LIBCPP_HIDE_FROM_ABI char_type operator*() const { return static_cast<char_type>(__sbuf_->sgetc()); }
0078   _LIBCPP_HIDE_FROM_ABI istreambuf_iterator& operator++() {
0079     __sbuf_->sbumpc();
0080     return *this;
0081   }
0082   _LIBCPP_HIDE_FROM_ABI __proxy operator++(int) { return __proxy(__sbuf_->sbumpc(), __sbuf_); }
0083
0084   _LIBCPP_HIDE_FROM_ABI bool equal(const istreambuf_iterator& __b) const {
0085     return __test_for_eof() == __b.__test_for_eof();
0086   }
0087
0088 #if _LIBCPP_STD_VER >= 20
0089   friend _LIBCPP_HIDE_FROM_ABI bool operator==(const istreambuf_iterator& __i, default_sentinel_t) {
0090     return __i.__test_for_eof();
0091   }
0092 #endif // _LIBCPP_STD_VER >= 20
0093 };
0094
0095 template <class _CharT, class _Traits>
0096 inline _LIBCPP_HIDE_FROM_ABI bool
0097 operator==(const istreambuf_iterator<_CharT, _Traits>& __a, const istreambuf_iterator<_CharT, _Traits>& __b) {
0098   return __a.equal(__b);
0099 }
0100
0101 #if _LIBCPP_STD_VER <= 17
0102 template <class _CharT, class _Traits>
0103 inline _LIBCPP_HIDE_FROM_ABI bool
0104 operator!=(const istreambuf_iterator<_CharT, _Traits>& __a, const istreambuf_iterator<_CharT, _Traits>& __b) {
0105   return !__a.equal(__b);
0106 }
0107 #endif // _LIBCPP_STD_VER <= 17
0108
0109 _LIBCPP_END_NAMESPACE_STD
0110
0111 #endif // _LIBCPP___ITERATOR_ISTREAMBUF_ITERATOR_H