libstdc++
initializer_list
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1 // std::initializer_list support -*- C++ -*-
2 
3 // Copyright (C) 2008-2024 Free Software Foundation, Inc.
4 //
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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 #include <bits/c++config.h>
40 
41 namespace std _GLIBCXX_VISIBILITY(default)
42 {
43  /// initializer_list
44  template<class _E>
45  class initializer_list
46  {
47  public:
48  typedef _E value_type;
49  typedef const _E& reference;
50  typedef const _E& const_reference;
51  typedef size_t size_type;
52  typedef const _E* iterator;
53  typedef const _E* const_iterator;
54 
55  private:
56  iterator _M_array;
57  size_type _M_len;
58 
59  // The compiler can call a private constructor.
60  constexpr initializer_list(const_iterator __a, size_type __l)
61  : _M_array(__a), _M_len(__l) { }
62 
63  public:
64  constexpr initializer_list() noexcept
65  : _M_array(0), _M_len(0) { }
66 
67  // Number of elements.
68  constexpr size_type
69  size() const noexcept { return _M_len; }
70 
71  // First element.
72  constexpr const_iterator
73  begin() const noexcept { return _M_array; }
74 
75  // One past the last element.
76  constexpr const_iterator
77  end() const noexcept { return begin() + size(); }
78  };
79 
80  /**
81  * @brief Return an iterator pointing to the first element of
82  * the initializer_list.
83  * @param __ils Initializer list.
84  * @relates initializer_list
85  */
86  template<class _Tp>
87  constexpr const _Tp*
88  begin(initializer_list<_Tp> __ils) noexcept
89  { return __ils.begin(); }
90 
91  /**
92  * @brief Return an iterator pointing to one past the last element
93  * of the initializer_list.
94  * @param __ils Initializer list.
95  * @relates initializer_list
96  */
97  template<class _Tp>
98  constexpr const _Tp*
99  end(initializer_list<_Tp> __ils) noexcept
100  { return __ils.end(); }
101 }
102 
103 #endif // C++11
104 
105 #endif // _INITIALIZER_LIST