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_BEGIN_NAMESPACE_STD
25 
26 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
27 template <class _Container>
28 class _LIBCPP_TEMPLATE_VIS front_insert_iterator
29 #if _LIBCPP_STD_VER <= 14 || !defined(_LIBCPP_ABI_NO_ITERATOR_BASES)
30     : public iterator<output_iterator_tag, void, void, void, void>
31 #endif
32 {
33 _LIBCPP_SUPPRESS_DEPRECATED_POP
34 protected:
35     _Container* container;
36 public:
37     typedef output_iterator_tag iterator_category;
38     typedef void value_type;
39 #if _LIBCPP_STD_VER > 17
40     typedef ptrdiff_t difference_type;
41 #else
42     typedef void difference_type;
43 #endif
44     typedef void pointer;
45     typedef void reference;
46     typedef _Container container_type;
47 
48     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 explicit front_insert_iterator(_Container& __x) : container(_VSTD::addressof(__x)) {}
49     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 front_insert_iterator& operator=(const typename _Container::value_type& __value)
50         {container->push_front(__value); return *this;}
51 #ifndef _LIBCPP_CXX03_LANG
52     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 front_insert_iterator& operator=(typename _Container::value_type&& __value)
53         {container->push_front(_VSTD::move(__value)); return *this;}
54 #endif // _LIBCPP_CXX03_LANG
55     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 front_insert_iterator& operator*()     {return *this;}
56     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 front_insert_iterator& operator++()    {return *this;}
57     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 front_insert_iterator  operator++(int) {return *this;}
58 };
59 
60 template <class _Container>
61 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
62 front_insert_iterator<_Container>
63 front_inserter(_Container& __x)
64 {
65     return front_insert_iterator<_Container>(__x);
66 }
67 
68 _LIBCPP_END_NAMESPACE_STD
69 
70 #endif // _LIBCPP___ITERATOR_FRONT_INSERT_ITERATOR_H
71