xref: /openbsd-src/gnu/llvm/libcxx/include/__iterator/istreambuf_iterator.h (revision 1ad61ae0a79a724d2d3ec69e69c8e1d1ff6b53a0)
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/iterator.h>
15 #include <__iterator/iterator_traits.h>
16 #include <iosfwd> // for forward declaration of basic_streambuf
17 
18 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
19 #pragma GCC system_header
20 #endif
21 
22 _LIBCPP_PUSH_MACROS
23 #include <__undef_macros>
24 
25 _LIBCPP_BEGIN_NAMESPACE_STD
26 
27 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
28 template<class _CharT, class _Traits>
29 class _LIBCPP_TEMPLATE_VIS istreambuf_iterator
30 #if _LIBCPP_STD_VER <= 14 || !defined(_LIBCPP_ABI_NO_ITERATOR_BASES)
31     : public iterator<input_iterator_tag, _CharT,
32                       typename _Traits::off_type, _CharT*,
33                       _CharT>
34 #endif
35 {
36 _LIBCPP_SUPPRESS_DEPRECATED_POP
37 public:
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 private:
49     mutable streambuf_type* __sbuf_;
50 
51     class __proxy
52     {
53         char_type __keep_;
54         streambuf_type* __sbuf_;
55         _LIBCPP_INLINE_VISIBILITY __proxy(char_type __c, streambuf_type* __s)
56             : __keep_(__c), __sbuf_(__s) {}
57         friend class istreambuf_iterator;
58     public:
59         _LIBCPP_INLINE_VISIBILITY char_type operator*() const {return __keep_;}
60     };
61 
62     _LIBCPP_INLINE_VISIBILITY
63     bool __test_for_eof() const
64     {
65         if (__sbuf_ && traits_type::eq_int_type(__sbuf_->sgetc(), traits_type::eof()))
66             __sbuf_ = nullptr;
67         return __sbuf_ == nullptr;
68     }
69 public:
70     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR istreambuf_iterator() _NOEXCEPT : __sbuf_(nullptr) {}
71     _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(istream_type& __s) _NOEXCEPT
72         : __sbuf_(__s.rdbuf()) {}
73     _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(streambuf_type* __s) _NOEXCEPT
74         : __sbuf_(__s) {}
75     _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(const __proxy& __p) _NOEXCEPT
76         : __sbuf_(__p.__sbuf_) {}
77 
78     _LIBCPP_INLINE_VISIBILITY char_type  operator*() const
79         {return static_cast<char_type>(__sbuf_->sgetc());}
80     _LIBCPP_INLINE_VISIBILITY istreambuf_iterator& operator++()
81         {
82             __sbuf_->sbumpc();
83             return *this;
84         }
85     _LIBCPP_INLINE_VISIBILITY __proxy              operator++(int)
86         {
87             return __proxy(__sbuf_->sbumpc(), __sbuf_);
88         }
89 
90     _LIBCPP_INLINE_VISIBILITY bool equal(const istreambuf_iterator& __b) const
91         {return __test_for_eof() == __b.__test_for_eof();}
92 };
93 
94 template <class _CharT, class _Traits>
95 inline _LIBCPP_INLINE_VISIBILITY
96 bool operator==(const istreambuf_iterator<_CharT,_Traits>& __a,
97                 const istreambuf_iterator<_CharT,_Traits>& __b)
98                 {return __a.equal(__b);}
99 
100 template <class _CharT, class _Traits>
101 inline _LIBCPP_INLINE_VISIBILITY
102 bool operator!=(const istreambuf_iterator<_CharT,_Traits>& __a,
103                 const istreambuf_iterator<_CharT,_Traits>& __b)
104                 {return !__a.equal(__b);}
105 
106 _LIBCPP_END_NAMESPACE_STD
107 
108 _LIBCPP_POP_MACROS
109 
110 #endif // _LIBCPP___ITERATOR_ISTREAMBUF_ITERATOR_H
111