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 <__iterator/default_sentinel.h>
15 #include <__iterator/iterator.h>
16 #include <__iterator/iterator_traits.h>
17 #include <iosfwd> // for forward declaration of basic_streambuf
18 
19 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
20 #  pragma GCC system_header
21 #endif
22 
23 _LIBCPP_BEGIN_NAMESPACE_STD
24 
25 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
26 template<class _CharT, class _Traits>
27 class _LIBCPP_TEMPLATE_VIS istreambuf_iterator
28 #if _LIBCPP_STD_VER <= 14 || !defined(_LIBCPP_ABI_NO_ITERATOR_BASES)
29     : public iterator<input_iterator_tag, _CharT,
30                       typename _Traits::off_type, _CharT*,
31                       _CharT>
32 #endif
33 {
34 _LIBCPP_SUPPRESS_DEPRECATED_POP
35 public:
36     typedef input_iterator_tag              iterator_category;
37     typedef _CharT                          value_type;
38     typedef typename _Traits::off_type      difference_type;
39     typedef _CharT*                         pointer;
40     typedef _CharT                          reference;
41     typedef _CharT                          char_type;
42     typedef _Traits                         traits_type;
43     typedef typename _Traits::int_type      int_type;
44     typedef basic_streambuf<_CharT,_Traits> streambuf_type;
45     typedef basic_istream<_CharT,_Traits>   istream_type;
46 private:
47     mutable streambuf_type* __sbuf_;
48 
49     class __proxy
50     {
51         char_type __keep_;
52         streambuf_type* __sbuf_;
53         _LIBCPP_INLINE_VISIBILITY __proxy(char_type __c, streambuf_type* __s)
54             : __keep_(__c), __sbuf_(__s) {}
55         friend class istreambuf_iterator;
56     public:
57         _LIBCPP_INLINE_VISIBILITY char_type operator*() const {return __keep_;}
58     };
59 
60     _LIBCPP_INLINE_VISIBILITY
61     bool __test_for_eof() const
62     {
63         if (__sbuf_ && traits_type::eq_int_type(__sbuf_->sgetc(), traits_type::eof()))
64             __sbuf_ = nullptr;
65         return __sbuf_ == nullptr;
66     }
67 public:
68     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR istreambuf_iterator() _NOEXCEPT : __sbuf_(nullptr) {}
69 #if _LIBCPP_STD_VER > 17
70     _LIBCPP_INLINE_VISIBILITY constexpr istreambuf_iterator(default_sentinel_t) noexcept
71         : istreambuf_iterator() {}
72 #endif // _LIBCPP_STD_VER > 17
73     _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(istream_type& __s) _NOEXCEPT
74         : __sbuf_(__s.rdbuf()) {}
75     _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(streambuf_type* __s) _NOEXCEPT
76         : __sbuf_(__s) {}
77     _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(const __proxy& __p) _NOEXCEPT
78         : __sbuf_(__p.__sbuf_) {}
79 
80     _LIBCPP_INLINE_VISIBILITY char_type  operator*() const
81         {return static_cast<char_type>(__sbuf_->sgetc());}
82     _LIBCPP_INLINE_VISIBILITY istreambuf_iterator& operator++()
83         {
84             __sbuf_->sbumpc();
85             return *this;
86         }
87     _LIBCPP_INLINE_VISIBILITY __proxy              operator++(int)
88         {
89             return __proxy(__sbuf_->sbumpc(), __sbuf_);
90         }
91 
92     _LIBCPP_INLINE_VISIBILITY bool equal(const istreambuf_iterator& __b) const
93         {return __test_for_eof() == __b.__test_for_eof();}
94 
95 #if _LIBCPP_STD_VER > 17
96     friend _LIBCPP_HIDE_FROM_ABI bool operator==(const istreambuf_iterator& __i, default_sentinel_t) {
97       return __i.__test_for_eof();
98     }
99 #endif // _LIBCPP_STD_VER > 17
100 };
101 
102 template <class _CharT, class _Traits>
103 inline _LIBCPP_INLINE_VISIBILITY
104 bool operator==(const istreambuf_iterator<_CharT,_Traits>& __a,
105                 const istreambuf_iterator<_CharT,_Traits>& __b)
106                 {return __a.equal(__b);}
107 
108 #if _LIBCPP_STD_VER <= 17
109 template <class _CharT, class _Traits>
110 inline _LIBCPP_INLINE_VISIBILITY
111 bool operator!=(const istreambuf_iterator<_CharT,_Traits>& __a,
112                 const istreambuf_iterator<_CharT,_Traits>& __b)
113                 {return !__a.equal(__b);}
114 #endif // _LIBCPP_STD_VER <= 17
115 
116 _LIBCPP_END_NAMESPACE_STD
117 
118 #endif // _LIBCPP___ITERATOR_ISTREAMBUF_ITERATOR_H
119