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 #include <__string/char_traits.h>
  20 #include <iosfwd>
  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 _CharT, class _Traits>
  30 class _LIBCPP_TEMPLATE_VIS istreambuf_iterator
  31 #if _LIBCPP_STD_VER <= 14 || !defined(_LIBCPP_ABI_NO_ITERATOR_BASES)
  32     : public iterator<input_iterator_tag, _CharT, typename _Traits::off_type, _CharT*, _CharT>
  33 #endif
  34 {
  35   _LIBCPP_SUPPRESS_DEPRECATED_POP
  36
  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
  49 private:
  50   mutable streambuf_type* __sbuf_;
  51
  52   class __proxy {
  53     char_type __keep_;
  54     streambuf_type* __sbuf_;
  55     _LIBCPP_HIDE_FROM_ABI explicit __proxy(char_type __c, streambuf_type* __s) : __keep_(__c), __sbuf_(__s) {}
  56     friend class istreambuf_iterator;
  57
  58   public:
  59     _LIBCPP_HIDE_FROM_ABI char_type operator*() const { return __keep_; }
  60   };
  61
  62   _LIBCPP_HIDE_FROM_ABI bool __test_for_eof() const {
  63     if (__sbuf_ && traits_type::eq_int_type(__sbuf_->sgetc(), traits_type::eof()))
  64       __sbuf_ = nullptr;
  65     return __sbuf_ == nullptr;
  66   }
  67
  68 public:
  69   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR istreambuf_iterator() _NOEXCEPT : __sbuf_(nullptr) {}
  70 #if _LIBCPP_STD_VER >= 20
  71   _LIBCPP_HIDE_FROM_ABI constexpr istreambuf_iterator(default_sentinel_t) noexcept : istreambuf_iterator() {}
  72 #endif // _LIBCPP_STD_VER >= 20
  73   _LIBCPP_HIDE_FROM_ABI istreambuf_iterator(istream_type& __s) _NOEXCEPT : __sbuf_(__s.rdbuf()) {}
  74   _LIBCPP_HIDE_FROM_ABI istreambuf_iterator(streambuf_type* __s) _NOEXCEPT : __sbuf_(__s) {}
  75   _LIBCPP_HIDE_FROM_ABI istreambuf_iterator(const __proxy& __p) _NOEXCEPT : __sbuf_(__p.__sbuf_) {}
  76
  77   _LIBCPP_HIDE_FROM_ABI char_type operator*() const { return static_cast<char_type>(__sbuf_->sgetc()); }
  78   _LIBCPP_HIDE_FROM_ABI istreambuf_iterator& operator++() {
  79     __sbuf_->sbumpc();
  80     return *this;
  81   }
  82   _LIBCPP_HIDE_FROM_ABI __proxy operator++(int) { return __proxy(__sbuf_->sbumpc(), __sbuf_); }
  83
  84   _LIBCPP_HIDE_FROM_ABI bool equal(const istreambuf_iterator& __b) const {
  85     return __test_for_eof() == __b.__test_for_eof();
  86   }
  87
  88 #if _LIBCPP_STD_VER >= 20
  89   friend _LIBCPP_HIDE_FROM_ABI bool operator==(const istreambuf_iterator& __i, default_sentinel_t) {
  90     return __i.__test_for_eof();
  91   }
  92 #endif // _LIBCPP_STD_VER >= 20
  93 };
  94
  95 template <class _CharT, class _Traits>
  96 inline _LIBCPP_HIDE_FROM_ABI bool
  97 operator==(const istreambuf_iterator<_CharT, _Traits>& __a, const istreambuf_iterator<_CharT, _Traits>& __b) {
  98   return __a.equal(__b);
  99 }
 100
 101 #if _LIBCPP_STD_VER <= 17
 102 template <class _CharT, class _Traits>
 103 inline _LIBCPP_HIDE_FROM_ABI bool
 104 operator!=(const istreambuf_iterator<_CharT, _Traits>& __a, const istreambuf_iterator<_CharT, _Traits>& __b) {
 105   return !__a.equal(__b);
 106 }
 107 #endif // _LIBCPP_STD_VER <= 17
 108
 109 _LIBCPP_END_NAMESPACE_STD
 110
 111 #endif // _LIBCPP___ITERATOR_ISTREAMBUF_ITERATOR_H