libstdc++
initializer_list
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1 // std::initializer_list support -*- C++ -*-
2 
3 // Copyright (C) 2008-2022 Free Software Foundation, Inc.
4 //
5 // This file is part of GCC.
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20 
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25 
26 /** @file initializer_list
27  * This is a Standard C++ Library header.
28  */
29 
30 #ifndef _INITIALIZER_LIST
31 #define _INITIALIZER_LIST
32 
33 #pragma GCC system_header
34 
35 #if __cplusplus < 201103L
36 # include <bits/c++0x_warning.h>
37 #else // C++0x
38 
39 #pragma GCC visibility push(default)
40 
41 #include <bits/c++config.h>
42 
43 namespace std
44 {
45  /// initializer_list
46  template<class _E>
48  {
49  public:
50  typedef _E value_type;
51  typedef const _E& reference;
52  typedef const _E& const_reference;
53  typedef size_t size_type;
54  typedef const _E* iterator;
55  typedef const _E* const_iterator;
56 
57  private:
58  iterator _M_array;
59  size_type _M_len;
60 
61  // The compiler can call a private constructor.
62  constexpr initializer_list(const_iterator __a, size_type __l)
63  : _M_array(__a), _M_len(__l) { }
64 
65  public:
66  constexpr initializer_list() noexcept
67  : _M_array(0), _M_len(0) { }
68 
69  // Number of elements.
70  constexpr size_type
71  size() const noexcept { return _M_len; }
72 
73  // First element.
74  constexpr const_iterator
75  begin() const noexcept { return _M_array; }
76 
77  // One past the last element.
78  constexpr const_iterator
79  end() const noexcept { return begin() + size(); }
80  };
81 
82  /**
83  * @brief Return an iterator pointing to the first element of
84  * the initializer_list.
85  * @param __ils Initializer list.
86  * @relates initializer_list
87  */
88  template<class _Tp>
89  constexpr const _Tp*
90  begin(initializer_list<_Tp> __ils) noexcept
91  { return __ils.begin(); }
92 
93  /**
94  * @brief Return an iterator pointing to one past the last element
95  * of the initializer_list.
96  * @param __ils Initializer list.
97  * @relates initializer_list
98  */
99  template<class _Tp>
100  constexpr const _Tp*
101  end(initializer_list<_Tp> __ils) noexcept
102  { return __ils.end(); }
103 }
104 
105 #pragma GCC visibility pop
106 
107 #endif // C++11
108 
109 #endif // _INITIALIZER_LIST
ISO C++ entities toplevel namespace is std.
initializer_list
constexpr const _Tp * begin(initializer_list< _Tp > __ils) noexcept
Return an iterator pointing to the first element of the initializer_list.
constexpr const _Tp * end(initializer_list< _Tp > __ils) noexcept
Return an iterator pointing to one past the last element of the initializer_list.