libcxx/include/__iterator/front_insert_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_FRONT_INSERT_ITERATOR_H
  11 #define _LIBCPP___ITERATOR_FRONT_INSERT_ITERATOR_H
  12
  13 #include <__config>
  14 #include <__iterator/iterator.h>
  15 #include <__iterator/iterator_traits.h>
  16 #include <__memory/addressof.h>
  17 #include <__utility/move.h>
  18 #include <cstddef>
  19
  20 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  21 #  pragma GCC system_header
  22 #endif
  23
  24 _LIBCPP_PUSH_MACROS
  25 #include <__undef_macros>
  26
  27 _LIBCPP_BEGIN_NAMESPACE_STD
  28
  29 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
  30 template <class _Container>
  31 class _LIBCPP_TEMPLATE_VIS front_insert_iterator
  32 #if _LIBCPP_STD_VER <= 14 || !defined(_LIBCPP_ABI_NO_ITERATOR_BASES)
  33     : public iterator<output_iterator_tag, void, void, void, void>
  34 #endif
  35 {
  36 _LIBCPP_SUPPRESS_DEPRECATED_POP
  37 protected:
  38     _Container* container;
  39 public:
  40     typedef output_iterator_tag iterator_category;
  41     typedef void value_type;
  42 #if _LIBCPP_STD_VER >= 20
  43     typedef ptrdiff_t difference_type;
  44 #else
  45     typedef void difference_type;
  46 #endif
  47     typedef void pointer;
  48     typedef void reference;
  49     typedef _Container container_type;
  50
  51     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit front_insert_iterator(_Container& __x) : container(_VSTD::addressof(__x)) {}
  52     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20 front_insert_iterator& operator=(const typename _Container::value_type& __value)
  53         {container->push_front(__value); return *this;}
  54 #ifndef _LIBCPP_CXX03_LANG
  55     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20 front_insert_iterator& operator=(typename _Container::value_type&& __value)
  56         {container->push_front(_VSTD::move(__value)); return *this;}
  57 #endif // _LIBCPP_CXX03_LANG
  58     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20 front_insert_iterator& operator*()     {return *this;}
  59     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20 front_insert_iterator& operator++()    {return *this;}
  60     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20 front_insert_iterator  operator++(int) {return *this;}
  61 };
  62 _LIBCPP_CTAD_SUPPORTED_FOR_TYPE(front_insert_iterator);
  63
  64 template <class _Container>
  65 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20
  66 front_insert_iterator<_Container>
  67 front_inserter(_Container& __x)
  68 {
  69     return front_insert_iterator<_Container>(__x);
  70 }
  71
  72 _LIBCPP_END_NAMESPACE_STD
  73
  74 _LIBCPP_POP_MACROS
  75
  76 #endif // _LIBCPP___ITERATOR_FRONT_INSERT_ITERATOR_H