libstdc++-v3/libsupc++/initializer_list

   1 // std::initializer_list support -*- C++ -*-
   2
   3 // Copyright (C) 2008-2020 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 #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>
  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 #pragma GCC visibility pop
 106
 107 #endif // C++11
 108
 109 #endif // _INITIALIZER_LIST