libcxx/include/__iterator/istreambuf_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_ISTREAMBUF_ITERATOR_H
  11 #define _LIBCPP___ITERATOR_ISTREAMBUF_ITERATOR_H
  12
  13 #include <__config>
  14 #include <__fwd/istream.h>
  15 #include <__fwd/streambuf.h>
  16 #include <__iterator/default_sentinel.h>
  17 #include <__iterator/iterator.h>
  18 #include <__iterator/iterator_traits.h>
  19
  20 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  21 #  pragma GCC system_header
  22 #endif
  23
  24 _LIBCPP_BEGIN_NAMESPACE_STD
  25
  26 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
  27 template<class _CharT, class _Traits>
  28 class _LIBCPP_TEMPLATE_VIS istreambuf_iterator
  29 #if _LIBCPP_STD_VER <= 14 || !defined(_LIBCPP_ABI_NO_ITERATOR_BASES)
  30     : public iterator<input_iterator_tag, _CharT,
  31                       typename _Traits::off_type, _CharT*,
  32                       _CharT>
  33 #endif
  34 {
  35 _LIBCPP_SUPPRESS_DEPRECATED_POP
  36 public:
  37     typedef input_iterator_tag              iterator_category;
  38     typedef _CharT                          value_type;
  39     typedef typename _Traits::off_type      difference_type;
  40     typedef _CharT*                         pointer;
  41     typedef _CharT                          reference;
  42     typedef _CharT                          char_type;
  43     typedef _Traits                         traits_type;
  44     typedef typename _Traits::int_type      int_type;
  45     typedef basic_streambuf<_CharT,_Traits> streambuf_type;
  46     typedef basic_istream<_CharT,_Traits>   istream_type;
  47 private:
  48     mutable streambuf_type* __sbuf_;
  49
  50     class __proxy
  51     {
  52         char_type __keep_;
  53         streambuf_type* __sbuf_;
  54         _LIBCPP_INLINE_VISIBILITY
  55         explicit __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 #if _LIBCPP_STD_VER >= 20
  72     _LIBCPP_INLINE_VISIBILITY constexpr istreambuf_iterator(default_sentinel_t) noexcept
  73         : istreambuf_iterator() {}
  74 #endif // _LIBCPP_STD_VER >= 20
  75     _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(istream_type& __s) _NOEXCEPT
  76         : __sbuf_(__s.rdbuf()) {}
  77     _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(streambuf_type* __s) _NOEXCEPT
  78         : __sbuf_(__s) {}
  79     _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(const __proxy& __p) _NOEXCEPT
  80         : __sbuf_(__p.__sbuf_) {}
  81
  82     _LIBCPP_INLINE_VISIBILITY char_type  operator*() const
  83         {return static_cast<char_type>(__sbuf_->sgetc());}
  84     _LIBCPP_INLINE_VISIBILITY istreambuf_iterator& operator++()
  85         {
  86             __sbuf_->sbumpc();
  87             return *this;
  88         }
  89     _LIBCPP_INLINE_VISIBILITY __proxy              operator++(int)
  90         {
  91             return __proxy(__sbuf_->sbumpc(), __sbuf_);
  92         }
  93
  94     _LIBCPP_INLINE_VISIBILITY bool equal(const istreambuf_iterator& __b) const
  95         {return __test_for_eof() == __b.__test_for_eof();}
  96
  97 #if _LIBCPP_STD_VER >= 20
  98     friend _LIBCPP_HIDE_FROM_ABI bool operator==(const istreambuf_iterator& __i, default_sentinel_t) {
  99       return __i.__test_for_eof();
 100     }
 101 #endif // _LIBCPP_STD_VER >= 20
 102 };
 103
 104 template <class _CharT, class _Traits>
 105 inline _LIBCPP_INLINE_VISIBILITY
 106 bool operator==(const istreambuf_iterator<_CharT,_Traits>& __a,
 107                 const istreambuf_iterator<_CharT,_Traits>& __b)
 108                 {return __a.equal(__b);}
 109
 110 #if _LIBCPP_STD_VER <= 17
 111 template <class _CharT, class _Traits>
 112 inline _LIBCPP_INLINE_VISIBILITY
 113 bool operator!=(const istreambuf_iterator<_CharT,_Traits>& __a,
 114                 const istreambuf_iterator<_CharT,_Traits>& __b)
 115                 {return !__a.equal(__b);}
 116 #endif // _LIBCPP_STD_VER <= 17
 117
 118 _LIBCPP_END_NAMESPACE_STD
 119
 120 #endif // _LIBCPP___ITERATOR_ISTREAMBUF_ITERATOR_H