libcxx/include/__iterator/ostreambuf_iterator.h

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP___ITERATOR_OSTREAMBUF_ITERATOR_H
#define _LIBCPP___ITERATOR_OSTREAMBUF_ITERATOR_H

#include <__algorithm/in_out_result.h>
#include <__algorithm/specialized_algorithms.h>
#include <__config>
#include <__cstddef/ptrdiff_t.h>
#include <__fwd/ios.h>
#include <__fwd/ostream.h>
#include <__fwd/streambuf.h>
#include <__iterator/iterator.h>
#include <__iterator/iterator_traits.h>
#include <__type_traits/is_same.h>
#include <iosfwd> // for forward declaration of ostreambuf_iterator

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#  pragma GCC system_header
#endif

_LIBCPP_BEGIN_NAMESPACE_STD

template <class _CharT, class _Traits>
class ostreambuf_iterator
    : public __iterator_base<ostreambuf_iterator<_CharT, _Traits>, output_iterator_tag, void, void, void, void> {
public:
  typedef output_iterator_tag iterator_category;
  typedef void value_type;
#if _LIBCPP_STD_VER >= 20
  typedef ptrdiff_t difference_type;
#else
  typedef void difference_type;
#endif
  typedef void pointer;
  typedef void reference;
  typedef _CharT char_type;
  typedef _Traits traits_type;
  typedef basic_streambuf<_CharT, _Traits> streambuf_type;
  typedef basic_ostream<_CharT, _Traits> ostream_type;

private:
  streambuf_type* __sbuf_;

public:
  _LIBCPP_HIDE_FROM_ABI ostreambuf_iterator(ostream_type& __s) _NOEXCEPT : __sbuf_(__s.rdbuf()) {}
  _LIBCPP_HIDE_FROM_ABI ostreambuf_iterator(streambuf_type* __s) _NOEXCEPT : __sbuf_(__s) {}
  _LIBCPP_HIDE_FROM_ABI ostreambuf_iterator& operator=(_CharT __c) {
    if (__sbuf_ && traits_type::eq_int_type(__sbuf_->sputc(__c), traits_type::eof()))
      __sbuf_ = nullptr;
    return *this;
  }
  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI ostreambuf_iterator& operator*() { return *this; }
  _LIBCPP_HIDE_FROM_ABI ostreambuf_iterator& operator++() { return *this; }
  _LIBCPP_HIDE_FROM_ABI ostreambuf_iterator& operator++(int) { return *this; }
  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI bool failed() const _NOEXCEPT { return __sbuf_ == nullptr; }

#if _LIBCPP_HAS_LOCALIZATION
  template <class _Ch, class _Tr>
  friend _LIBCPP_HIDE_FROM_ABI ostreambuf_iterator<_Ch, _Tr> __pad_and_output(
      ostreambuf_iterator<_Ch, _Tr> __s, const _Ch* __ob, const _Ch* __op, const _Ch* __oe, ios_base& __iob, _Ch __fl);
#endif // _LIBCPP_HAS_LOCALIZATION

  template <class, class...>
  friend struct __specialized_algorithm;
};

template <class _InCharT, class _CharT, class _Traits>
struct __specialized_algorithm<_Algorithm::__copy,
                               __iterator_pair<_InCharT*, _InCharT*>,
                               __single_iterator<ostreambuf_iterator<_CharT, _Traits> > > {
  static const bool __has_algorithm = is_same<const _CharT, const _InCharT>::value;

  _LIBCPP_HIDE_FROM_ABI static __in_out_result<_InCharT*, ostreambuf_iterator<_CharT, _Traits> >
  operator()(_InCharT* __first, _InCharT* __last, ostreambuf_iterator<_CharT, _Traits> __result) {
    auto __size = __last - __first;
    if (__result.__sbuf_ && __size > 0) {
      if (__result.__sbuf_->sputn(__first, __last - __first) != __size)
        __result.__sbuf_ = nullptr;
    }
    return {__last, __result};
  }
};

_LIBCPP_END_NAMESPACE_STD

#endif // _LIBCPP___ITERATOR_OSTREAMBUF_ITERATOR_H