v1/__iterator/istream_iterator.h

0001 // -*- C++ -*-
0002 //===----------------------------------------------------------------------===//
0003 //
0004 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0005 // See https://llvm.org/LICENSE.txt for license information.
0006 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0007 //
0008 //===----------------------------------------------------------------------===//
0009
0010 #ifndef _LIBCPP___ITERATOR_ISTREAM_ITERATOR_H
0011 #define _LIBCPP___ITERATOR_ISTREAM_ITERATOR_H
0012
0013 #include <__config>
0014 #include <__cstddef/ptrdiff_t.h>
0015 #include <__fwd/istream.h>
0016 #include <__fwd/string.h>
0017 #include <__iterator/default_sentinel.h>
0018 #include <__iterator/iterator.h>
0019 #include <__iterator/iterator_traits.h>
0020 #include <__memory/addressof.h>
0021
0022 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
0023 #  pragma GCC system_header
0024 #endif
0025
0026 _LIBCPP_BEGIN_NAMESPACE_STD
0027
0028 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
0029 template <class _Tp, class _CharT = char, class _Traits = char_traits<_CharT>, class _Distance = ptrdiff_t>
0030 class _LIBCPP_TEMPLATE_VIS istream_iterator
0031 #if _LIBCPP_STD_VER <= 14 || !defined(_LIBCPP_ABI_NO_ITERATOR_BASES)
0032     : public iterator<input_iterator_tag, _Tp, _Distance, const _Tp*, const _Tp&>
0033 #endif
0034 {
0035   _LIBCPP_SUPPRESS_DEPRECATED_POP
0036
0037 public:
0038   typedef input_iterator_tag iterator_category;
0039   typedef _Tp value_type;
0040   typedef _Distance difference_type;
0041   typedef const _Tp* pointer;
0042   typedef const _Tp& reference;
0043   typedef _CharT char_type;
0044   typedef _Traits traits_type;
0045   typedef basic_istream<_CharT, _Traits> istream_type;
0046
0047 private:
0048   istream_type* __in_stream_;
0049   _Tp __value_;
0050
0051 public:
0052   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR istream_iterator() : __in_stream_(nullptr), __value_() {}
0053 #if _LIBCPP_STD_VER >= 20
0054   _LIBCPP_HIDE_FROM_ABI constexpr istream_iterator(default_sentinel_t) : istream_iterator() {}
0055 #endif // _LIBCPP_STD_VER >= 20
0056   _LIBCPP_HIDE_FROM_ABI istream_iterator(istream_type& __s) : __in_stream_(std::addressof(__s)) {
0057     if (!(*__in_stream_ >> __value_))
0058       __in_stream_ = nullptr;
0059   }
0060
0061   _LIBCPP_HIDE_FROM_ABI const _Tp& operator*() const { return __value_; }
0062   _LIBCPP_HIDE_FROM_ABI const _Tp* operator->() const { return std::addressof((operator*())); }
0063   _LIBCPP_HIDE_FROM_ABI istream_iterator& operator++() {
0064     if (!(*__in_stream_ >> __value_))
0065       __in_stream_ = nullptr;
0066     return *this;
0067   }
0068   _LIBCPP_HIDE_FROM_ABI istream_iterator operator++(int) {
0069     istream_iterator __t(*this);
0070     ++(*this);
0071     return __t;
0072   }
0073
0074   template <class _Up, class _CharU, class _TraitsU, class _DistanceU>
0075   friend _LIBCPP_HIDE_FROM_ABI bool operator==(const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __x,
0076                                                const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __y);
0077
0078 #if _LIBCPP_STD_VER >= 20
0079   friend _LIBCPP_HIDE_FROM_ABI bool operator==(const istream_iterator& __i, default_sentinel_t) {
0080     return __i.__in_stream_ == nullptr;
0081   }
0082 #endif // _LIBCPP_STD_VER >= 20
0083 };
0084
0085 template <class _Tp, class _CharT, class _Traits, class _Distance>
0086 inline _LIBCPP_HIDE_FROM_ABI bool operator==(const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __x,
0087                                              const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __y) {
0088   return __x.__in_stream_ == __y.__in_stream_;
0089 }
0090
0091 #if _LIBCPP_STD_VER <= 17
0092 template <class _Tp, class _CharT, class _Traits, class _Distance>
0093 inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __x,
0094                                              const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __y) {
0095   return !(__x == __y);
0096 }
0097 #endif // _LIBCPP_STD_VER <= 17
0098
0099 _LIBCPP_END_NAMESPACE_STD
0100
0101 #endif // _LIBCPP___ITERATOR_ISTREAM_ITERATOR_H