libstdc++-v3/testsuite/23_containers/vector/modifiers/insert/aliasing.cc

   1 // Copyright (C) 2016-2020 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++14 } }
  19
  20 #include <vector>
  21 #include <memory>
  22 #include <testsuite_hooks.h>
  23
  24 // See https://gcc.gnu.org/ml/libstdc++/2016-07/msg00008.html for background.
  25
  26 struct T
  27 {
  28  T(int v = 0) : value(v) { }
  29  T(const T& t);
  30  T& operator=(const T& t);
  31  void make_child() { child = std::make_unique<T>(value + 10); }
  32  std::unique_ptr<T> child;
  33  int value;
  34 };
  35
  36 T::T(const T& t) : value(t.value)
  37 {
  38  if (t.child)
  39    child.reset(new T(*t.child));
  40 }
  41
  42 T& T::operator=(const T& t)
  43 {
  44  value = t.value;
  45  if (t.child)
  46  {
  47    if (child)
  48      *child = *t.child;
  49    else
  50      child.reset(new T(*t.child));
  51  }
  52  else
  53    child.reset();
  54  return *this;
  55 }
  56
  57 void
  58 test01()
  59 {
  60  std::vector<T> v;
  61  v.reserve(3);
  62  v.push_back(T(1));
  63  v.back().make_child();
  64  v.push_back(T(2));
  65  v.back().make_child();
  66
  67  VERIFY(v[1].child->value == 12);
  68  VERIFY(v[1].child->child == nullptr);
  69
  70  v.insert(v.begin(), *v[1].child);
  71
  72  VERIFY(v[0].value == 12);
  73  VERIFY(v[0].child == nullptr);
  74 }
  75
  76 int main()
  77 {
  78   test01();
  79 }