1// -*- C++ -*-
  2//===----------------------------------------------------------------------===//
  3//
  4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  5// See https://llvm.org/LICENSE.txt for license information.
  6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  7//
  8//===----------------------------------------------------------------------===//
  9
 10#ifndef _LIBCPP___ITERATOR_ISTREAMBUF_ITERATOR_H
 11#define _LIBCPP___ITERATOR_ISTREAMBUF_ITERATOR_H
 12
 13#include <__config>
 14#include <__fwd/istream.h>
 15#include <__fwd/streambuf.h>
 16#include <__iterator/default_sentinel.h>
 17#include <__iterator/iterator.h>
 18#include <__iterator/iterator_traits.h>
 19#include <__string/char_traits.h>
 20#include <iosfwd>
 21
 22#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 23#  pragma GCC system_header
 24#endif
 25
 26_LIBCPP_BEGIN_NAMESPACE_STD
 27
 28_LIBCPP_SUPPRESS_DEPRECATED_PUSH
 29template <class _CharT, class _Traits>
 30class istreambuf_iterator
 31#if _LIBCPP_STD_VER <= 14 || !defined(_LIBCPP_ABI_NO_ITERATOR_BASES)
 32    : public iterator<input_iterator_tag, _CharT, typename _Traits::off_type, _CharT*, _CharT>
 33#endif
 34{
 35  _LIBCPP_SUPPRESS_DEPRECATED_POP
 36
 37public:
 38  typedef input_iterator_tag iterator_category;
 39  typedef _CharT value_type;
 40  typedef typename _Traits::off_type difference_type;
 41  typedef _CharT* pointer;
 42  typedef _CharT reference;
 43  typedef _CharT char_type;
 44  typedef _Traits traits_type;
 45  typedef typename _Traits::int_type int_type;
 46  typedef basic_streambuf<_CharT, _Traits> streambuf_type;
 47  typedef basic_istream<_CharT, _Traits> istream_type;
 48
 49private:
 50  mutable streambuf_type* __sbuf_;
 51
 52  class __proxy {
 53    char_type __keep_;
 54    streambuf_type* __sbuf_;
 55    _LIBCPP_HIDE_FROM_ABI explicit __proxy(char_type __c, streambuf_type* __s) : __keep_(__c), __sbuf_(__s) {}
 56    friend class istreambuf_iterator;
 57
 58  public:
 59    _LIBCPP_HIDE_FROM_ABI char_type operator*() const { return __keep_; }
 60  };
 61
 62  _LIBCPP_HIDE_FROM_ABI bool __test_for_eof() const {
 63    if (__sbuf_ && traits_type::eq_int_type(__sbuf_->sgetc(), traits_type::eof()))
 64      __sbuf_ = nullptr;
 65    return __sbuf_ == nullptr;
 66  }
 67
 68public:
 69  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR istreambuf_iterator() _NOEXCEPT : __sbuf_(nullptr) {}
 70#if _LIBCPP_STD_VER >= 20
 71  _LIBCPP_HIDE_FROM_ABI constexpr istreambuf_iterator(default_sentinel_t) noexcept : istreambuf_iterator() {}
 72#endif // _LIBCPP_STD_VER >= 20
 73  _LIBCPP_HIDE_FROM_ABI istreambuf_iterator(istream_type& __s) _NOEXCEPT : __sbuf_(__s.rdbuf()) {}
 74  _LIBCPP_HIDE_FROM_ABI istreambuf_iterator(streambuf_type* __s) _NOEXCEPT : __sbuf_(__s) {}
 75  _LIBCPP_HIDE_FROM_ABI istreambuf_iterator(const __proxy& __p) _NOEXCEPT : __sbuf_(__p.__sbuf_) {}
 76
 77  _LIBCPP_HIDE_FROM_ABI char_type operator*() const { return static_cast<char_type>(__sbuf_->sgetc()); }
 78  _LIBCPP_HIDE_FROM_ABI istreambuf_iterator& operator++() {
 79    __sbuf_->sbumpc();
 80    return *this;
 81  }
 82  _LIBCPP_HIDE_FROM_ABI __proxy operator++(int) { return __proxy(__sbuf_->sbumpc(), __sbuf_); }
 83
 84  _LIBCPP_HIDE_FROM_ABI bool equal(const istreambuf_iterator& __b) const {
 85    return __test_for_eof() == __b.__test_for_eof();
 86  }
 87
 88#if _LIBCPP_STD_VER >= 20
 89  friend _LIBCPP_HIDE_FROM_ABI bool operator==(const istreambuf_iterator& __i, default_sentinel_t) {
 90    return __i.__test_for_eof();
 91  }
 92#endif // _LIBCPP_STD_VER >= 20
 93};
 94
 95template <class _CharT, class _Traits>
 96inline _LIBCPP_HIDE_FROM_ABI bool
 97operator==(const istreambuf_iterator<_CharT, _Traits>& __a, const istreambuf_iterator<_CharT, _Traits>& __b) {
 98  return __a.equal(__b);
 99}
100
101#if _LIBCPP_STD_VER <= 17
102template <class _CharT, class _Traits>
103inline _LIBCPP_HIDE_FROM_ABI bool
104operator!=(const istreambuf_iterator<_CharT, _Traits>& __a, const istreambuf_iterator<_CharT, _Traits>& __b) {
105  return !__a.equal(__b);
106}
107#endif // _LIBCPP_STD_VER <= 17
108
109_LIBCPP_END_NAMESPACE_STD
110
111#endif // _LIBCPP___ITERATOR_ISTREAMBUF_ITERATOR_H