libcxx/test/std/containers/sequences/deque/deque.modifiers/push_front_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_front(const value_type& x);
  13
  14 #include <deque>
  15 #include <cassert>
  16 #include "test_macros.h"
  17 #include "test_allocator.h"
  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     private:
  30         int fMagicValue;
  31         int fTag;
  32
  33     private: static int kStartedConstructionMagicValue;
  34     private: static int kFinishedConstructionMagicValue;
  35 };
  36
  37 // Value for fMagicValue when the constructor has started running, but not yet finished
  38 int CMyClass::kStartedConstructionMagicValue = 0;
  39 // Value for fMagicValue when the constructor has finished running
  40 int CMyClass::kFinishedConstructionMagicValue = 12345;
  41
  42 CMyClass::CMyClass(int tag) :
  43     fMagicValue(kStartedConstructionMagicValue), fTag(tag)
  44 {
  45     // Signal that the constructor has finished running
  46     fMagicValue = kFinishedConstructionMagicValue;
  47 }
  48
  49 CMyClass::CMyClass(const CMyClass& iOther) :
  50     fMagicValue(kStartedConstructionMagicValue), fTag(iOther.fTag)
  51 {
  52     // If requested, throw an exception _before_ setting fMagicValue to kFinishedConstructionMagicValue
  53     if (gCopyConstructorShouldThrow) {
  54       throw std::exception();
  55     }
  56     // Signal that the constructor has finished running
  57     fMagicValue = kFinishedConstructionMagicValue;
  58 }
  59
  60 CMyClass::~CMyClass() {
  61     // Only instances for which the constructor has finished running should be destructed
  62     assert(fMagicValue == kFinishedConstructionMagicValue);
  63 }
  64
  65 bool operator==(const CMyClass &lhs, const CMyClass &rhs) { return lhs.equal(rhs); }
  66
  67 int main(int, char**)
  68 {
  69     CMyClass instance(42);
  70     {
  71     std::deque<CMyClass> vec;
  72
  73     vec.push_front(instance);
  74     std::deque<CMyClass> vec2(vec);
  75
  76     gCopyConstructorShouldThrow = true;
  77     try {
  78         vec.push_front(instance);
  79         assert(false);
  80     }
  81     catch (...) {
  82       gCopyConstructorShouldThrow = false;
  83       assert(vec == vec2);
  84     }
  85     }
  86
  87     {
  88     test_allocator_statistics alloc_stats;
  89     typedef std::deque<CMyClass, test_allocator<CMyClass> > C;
  90     C vec((test_allocator<CMyClass>(&alloc_stats)));
  91     C vec2(vec, test_allocator<CMyClass>(&alloc_stats));
  92
  93     alloc_stats.throw_after = 1;
  94     try {
  95         vec.push_front(instance);
  96         assert(false);
  97     }
  98     catch (...) {
  99         assert(vec==vec2);
 100     }
 101     }
 102
 103   return 0;
 104 }