libstdc++: initializer_list Source File

libstdc++

initializer_list
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1// std::initializer_list support -*- C++ -*-
2
3// Copyright (C) 2008-2026 Free Software Foundation, Inc.
4//
5// This file is part of GCC.
6//
7// GCC is free software; you can redistribute it and/or modify
8// it under the terms of the GNU General Public License as published by
9// the Free Software Foundation; either version 3, or (at your option)
10// any later version.
11//
12// GCC is distributed in the hope that it will be useful,
13// but WITHOUT ANY WARRANTY; without even the implied warranty of
14// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15// GNU General Public License for more details.
16//
17// Under Section 7 of GPL version 3, you are granted additional
18// permissions described in the GCC Runtime Library Exception, version
19// 3.1, as published by the Free Software Foundation.
20
21// You should have received a copy of the GNU General Public License and
22// a copy of the GCC Runtime Library Exception along with this program;
23// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
24// <http://www.gnu.org/licenses/>.
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#ifdef _GLIBCXX_SYSHDR
34#pragma GCC system_header
35#endif
36
37#if __cplusplus < 201103L
38# include <bits/c++0x_warning.h>
39#else // C++0x
40
41#include <bits/c++config.h>
42
43namespace std _GLIBCXX_VISIBILITY(default)
44{
45 /// initializer_list
46 template<class _E>
47 class initializer_list
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#endif // C++11
106
107#endif // _INITIALIZER_LIST
c++0x_warning.h
c++config.h
std
ISO C++ entities toplevel namespace is std.
std::initializer_list::begin
constexpr const _Tp * begin(initializer_list< _Tp > __ils) noexcept
Return an iterator pointing to the first element of the initializer_list.
Definition initializer_list:90
std::initializer_list::end
constexpr const _Tp * end(initializer_list< _Tp > __ils) noexcept
Return an iterator pointing to one past the last element of the initializer_list.
Definition initializer_list:101