libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_default_n/sizes.cc

   1 // Copyright (C) 2020-2024 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 3, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING3.  If not see
  16 // <http://www.gnu.org/licenses/>.
  17
  18 // { dg-do run { target c++11 } }
  19
  20 #include <memory>
  21 #include <testsuite_hooks.h>
  22
  23 void
  24 test01()
  25 {
  26   int i[3];
  27   auto j = std::__uninitialized_default_n(i, 2.0001);
  28   VERIFY( j == (i + 3) );
  29 }
  30
  31 void
  32 test02()
  33 {
  34   // The standard only requires that n>0 and --n are valid expressions.
  35   struct Size
  36   {
  37     int value;
  38
  39     void operator--() { --value; }
  40
  41     int operator>(void*) { return value != 0; }
  42   };
  43
  44   int i[5] = { 1, 2, 3, 4, 5 };
  45   Size n = {4};
  46   auto j = std::__uninitialized_default_n(i, n);
  47   VERIFY( j == (i + 4) );
  48   // i[0:3] are default-initialized so have indeterminate values.
  49   VERIFY( i[4] == 5 );
  50 }
  51
  52 int
  53 main()
  54 {
  55   test01();
  56   test02();
  57 }