libstdc++-v3/testsuite/21_strings/basic_string/modifiers/assign/char/87749.cc

   1 // Copyright (C) 2018-2021 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 // PR libstdc++/87749
  21
  22 #include <string>
  23 #include <testsuite_hooks.h>
  24
  25 bool oom = false;
  26
  27 template<typename T>
  28 struct alloc
  29 {
  30   using value_type = T;
  31
  32 #if !_GLIBCXX_USE_CXX11_ABI
  33   using size_type = unsigned long;
  34   using difference_type = long;
  35   using reference = T&;
  36   using const_reference = T&;
  37   using pointer = T*;
  38   using const_pointer = const T*;
  39   template<typename U>
  40     struct rebind { using other = alloc<U>; };
  41 #endif
  42
  43   int not_empty = 0; // this makes is_always_equal false
  44
  45   alloc() = default;
  46   template<typename U>
  47     alloc(const alloc<U>&) { }
  48
  49   T* allocate(unsigned long n)
  50   {
  51     if (oom)
  52       throw std::bad_alloc();
  53     return std::allocator<T>().allocate(n);
  54   }
  55
  56   void deallocate(T* p, unsigned long n)
  57   {
  58     std::allocator<T>().deallocate(p, n);
  59   }
  60 };
  61
  62 template<typename T, typename U>
  63 bool operator==(const alloc<T>&, const alloc<U>&) { return true; }
  64
  65 template<typename T, typename U>
  66 bool operator!=(const alloc<T>&, const alloc<U>&) { return false; }
  67
  68 int main()
  69 {
  70   using string = std::basic_string<char, std::char_traits<char>, alloc<char>>;
  71
  72   string s = "PR libstdc++/87749 a string that is longer than a short string";
  73   const auto ptr = s.c_str();
  74   oom = true;
  75   string ss;
  76   ss = std::move(s); // allocators are equal, should not allocate new storage
  77   VERIFY( ss.c_str() == ptr );
  78 }