libcxx/include/__iterator/istream_iterator.h

   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_ISTREAM_ITERATOR_H
  11 #define _LIBCPP___ITERATOR_ISTREAM_ITERATOR_H
  12
  13 #include <__config>
  14 #include <__fwd/istream.h>
  15 #include <__fwd/string.h>
  16 #include <__iterator/default_sentinel.h>
  17 #include <__iterator/iterator.h>
  18 #include <__iterator/iterator_traits.h>
  19 #include <__memory/addressof.h>
  20 #include <cstddef>
  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
  29 template <class _Tp, class _CharT = char,
  30           class _Traits = char_traits<_CharT>, class _Distance = ptrdiff_t>
  31 class _LIBCPP_TEMPLATE_VIS istream_iterator
  32 #if _LIBCPP_STD_VER <= 14 || !defined(_LIBCPP_ABI_NO_ITERATOR_BASES)
  33     : public iterator<input_iterator_tag, _Tp, _Distance, const _Tp*, const _Tp&>
  34 #endif
  35 {
  36 _LIBCPP_SUPPRESS_DEPRECATED_POP
  37 public:
  38     typedef input_iterator_tag iterator_category;
  39     typedef _Tp value_type;
  40     typedef _Distance difference_type;
  41     typedef const _Tp* pointer;
  42     typedef const _Tp& reference;
  43     typedef _CharT char_type;
  44     typedef _Traits traits_type;
  45     typedef basic_istream<_CharT,_Traits> istream_type;
  46 private:
  47     istream_type* __in_stream_;
  48     _Tp __value_;
  49 public:
  50     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR istream_iterator() : __in_stream_(nullptr), __value_() {}
  51 #if _LIBCPP_STD_VER >= 20
  52     _LIBCPP_HIDE_FROM_ABI constexpr istream_iterator(default_sentinel_t) : istream_iterator() {}
  53 #endif // _LIBCPP_STD_VER >= 20
  54     _LIBCPP_INLINE_VISIBILITY istream_iterator(istream_type& __s) : __in_stream_(_VSTD::addressof(__s))
  55         {
  56             if (!(*__in_stream_ >> __value_))
  57                 __in_stream_ = nullptr;
  58         }
  59
  60     _LIBCPP_INLINE_VISIBILITY const _Tp& operator*() const {return __value_;}
  61     _LIBCPP_INLINE_VISIBILITY const _Tp* operator->() const {return _VSTD::addressof((operator*()));}
  62     _LIBCPP_INLINE_VISIBILITY istream_iterator& operator++()
  63         {
  64             if (!(*__in_stream_ >> __value_))
  65                 __in_stream_ = nullptr;
  66             return *this;
  67         }
  68     _LIBCPP_INLINE_VISIBILITY istream_iterator  operator++(int)
  69         {istream_iterator __t(*this); ++(*this); return __t;}
  70
  71     template <class _Up, class _CharU, class _TraitsU, class _DistanceU>
  72     friend _LIBCPP_INLINE_VISIBILITY
  73     bool
  74     operator==(const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __x,
  75                const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __y);
  76
  77 #if _LIBCPP_STD_VER >= 20
  78     friend _LIBCPP_HIDE_FROM_ABI bool operator==(const istream_iterator& __i, default_sentinel_t) {
  79       return __i.__in_stream_ == nullptr;
  80     }
  81 #endif // _LIBCPP_STD_VER >= 20
  82 };
  83
  84 template <class _Tp, class _CharT, class _Traits, class _Distance>
  85 inline _LIBCPP_INLINE_VISIBILITY
  86 bool
  87 operator==(const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __x,
  88            const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __y)
  89 {
  90     return __x.__in_stream_ == __y.__in_stream_;
  91 }
  92
  93 #if _LIBCPP_STD_VER <= 17
  94 template <class _Tp, class _CharT, class _Traits, class _Distance>
  95 inline _LIBCPP_INLINE_VISIBILITY
  96 bool
  97 operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __x,
  98            const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __y)
  99 {
 100     return !(__x == __y);
 101 }
 102 #endif // _LIBCPP_STD_VER <= 17
 103
 104 _LIBCPP_END_NAMESPACE_STD
 105
 106 #endif // _LIBCPP___ITERATOR_ISTREAM_ITERATOR_H