libcxx/test/std/containers/sequences/deque/deque.modifiers/push_back_exception_safety.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // UNSUPPORTED: no-exceptions
  10 // <deque>
  11
  12 // void push_back(const value_type& x);
  13
  14 #include <deque>
  15 #include "test_macros.h"
  16 #include "test_allocator.h"
  17 #include <cassert>
  18
  19 // Flag that makes the copy constructor for CMyClass throw an exception
  20 static bool gCopyConstructorShouldThrow = false;
  21
  22 class CMyClass {
  23     public: CMyClass(int tag);
  24     public: CMyClass(const CMyClass& iOther);
  25     public: ~CMyClass();
  26
  27     bool equal(const CMyClass &rhs) const
  28         { return fTag == rhs.fTag && fMagicValue == rhs.fMagicValue; }
  29
  30     private:
  31         int fMagicValue;
  32         int fTag;
  33
  34     private: static int kStartedConstructionMagicValue;
  35     private: static int kFinishedConstructionMagicValue;
  36 };
  37
  38 // Value for fMagicValue when the constructor has started running, but not yet finished
  39 int CMyClass::kStartedConstructionMagicValue = 0;
  40 // Value for fMagicValue when the constructor has finished running
  41 int CMyClass::kFinishedConstructionMagicValue = 12345;
  42
  43 CMyClass::CMyClass(int tag) :
  44     fMagicValue(kStartedConstructionMagicValue), fTag(tag)
  45 {
  46     // Signal that the constructor has finished running
  47     fMagicValue = kFinishedConstructionMagicValue;
  48 }
  49
  50 CMyClass::CMyClass(const CMyClass& iOther) :
  51     fMagicValue(kStartedConstructionMagicValue), fTag(iOther.fTag)
  52 {
  53     // If requested, throw an exception _before_ setting fMagicValue to kFinishedConstructionMagicValue
  54     if (gCopyConstructorShouldThrow) {
  55       throw std::exception();
  56     }
  57     // Signal that the constructor has finished running
  58     fMagicValue = kFinishedConstructionMagicValue;
  59 }
  60
  61 CMyClass::~CMyClass() {
  62     // Only instances for which the constructor has finished running should be destructed
  63     assert(fMagicValue == kFinishedConstructionMagicValue);
  64 }
  65
  66 bool operator==(const CMyClass &lhs, const CMyClass &rhs) { return lhs.equal(rhs); }
  67
  68 int main(int, char**)
  69 {
  70     CMyClass instance(42);
  71     {
  72     std::deque<CMyClass> vec;
  73
  74     vec.push_back(instance);
  75     std::deque<CMyClass> vec2(vec);
  76
  77     gCopyConstructorShouldThrow = true;
  78     try {
  79         vec.push_back(instance);
  80         assert(false);
  81     }
  82     catch (...) {
  83       gCopyConstructorShouldThrow = false;
  84       assert(vec == vec2);
  85     }
  86     }
  87
  88     {
  89     test_allocator_statistics alloc_stats;
  90     typedef std::deque<CMyClass, test_allocator<CMyClass> > C;
  91     C vec((test_allocator<CMyClass>(&alloc_stats)));
  92     C vec2(vec, test_allocator<CMyClass>(&alloc_stats));
  93
  94     alloc_stats.throw_after = 1;
  95     try {
  96         vec.push_back(instance);
  97         assert(false);
  98     }
  99     catch (...) {
 100         assert(vec==vec2);
 101     }
 102     }
 103
 104   return 0;
 105 }