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 <__cstddef/ptrdiff_t.h>
  15 #include <__fwd/istream.h>
  16 #include <__fwd/string.h>
  17 #include <__iterator/default_sentinel.h>
  18 #include <__iterator/iterator.h>
  19 #include <__iterator/iterator_traits.h>
  20 #include <__memory/addressof.h>
  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, class _Traits = char_traits<_CharT>, class _Distance = ptrdiff_t>
  30 class _LIBCPP_TEMPLATE_VIS istream_iterator
  31 #if _LIBCPP_STD_VER <= 14 || !defined(_LIBCPP_ABI_NO_ITERATOR_BASES)
  32     : public iterator<input_iterator_tag, _Tp, _Distance, const _Tp*, const _Tp&>
  33 #endif
  34 {
  35   _LIBCPP_SUPPRESS_DEPRECATED_POP
  36
  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
  47 private:
  48   istream_type* __in_stream_;
  49   _Tp __value_;
  50
  51 public:
  52   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR istream_iterator() : __in_stream_(nullptr), __value_() {}
  53 #if _LIBCPP_STD_VER >= 20
  54   _LIBCPP_HIDE_FROM_ABI constexpr istream_iterator(default_sentinel_t) : istream_iterator() {}
  55 #endif // _LIBCPP_STD_VER >= 20
  56   _LIBCPP_HIDE_FROM_ABI istream_iterator(istream_type& __s) : __in_stream_(std::addressof(__s)) {
  57     if (!(*__in_stream_ >> __value_))
  58       __in_stream_ = nullptr;
  59   }
  60
  61   _LIBCPP_HIDE_FROM_ABI const _Tp& operator*() const { return __value_; }
  62   _LIBCPP_HIDE_FROM_ABI const _Tp* operator->() const { return std::addressof((operator*())); }
  63   _LIBCPP_HIDE_FROM_ABI istream_iterator& operator++() {
  64     if (!(*__in_stream_ >> __value_))
  65       __in_stream_ = nullptr;
  66     return *this;
  67   }
  68   _LIBCPP_HIDE_FROM_ABI istream_iterator operator++(int) {
  69     istream_iterator __t(*this);
  70     ++(*this);
  71     return __t;
  72   }
  73
  74   template <class _Up, class _CharU, class _TraitsU, class _DistanceU>
  75   friend _LIBCPP_HIDE_FROM_ABI bool operator==(const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __x,
  76                                                const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __y);
  77
  78 #if _LIBCPP_STD_VER >= 20
  79   friend _LIBCPP_HIDE_FROM_ABI bool operator==(const istream_iterator& __i, default_sentinel_t) {
  80     return __i.__in_stream_ == nullptr;
  81   }
  82 #endif // _LIBCPP_STD_VER >= 20
  83 };
  84
  85 template <class _Tp, class _CharT, class _Traits, class _Distance>
  86 inline _LIBCPP_HIDE_FROM_ABI bool operator==(const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __x,
  87                                              const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __y) {
  88   return __x.__in_stream_ == __y.__in_stream_;
  89 }
  90
  91 #if _LIBCPP_STD_VER <= 17
  92 template <class _Tp, class _CharT, class _Traits, class _Distance>
  93 inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __x,
  94                                              const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __y) {
  95   return !(__x == __y);
  96 }
  97 #endif // _LIBCPP_STD_VER <= 17
  98
  99 _LIBCPP_END_NAMESPACE_STD
 100
 101 #endif // _LIBCPP___ITERATOR_ISTREAM_ITERATOR_H