在堆栈上分配的变量上调用 delete

2022-01-22 00:00:00 stack c++ heap-memory delete-operator

忽略编程风格和设计，对分配在堆栈上的变量调用 delete 是否安全"?

Ignoring programming style and design, is it "safe" to call delete on a variable allocated on the stack?

例如:

   int nAmount;
   delete &nAmount;

或

class sample
{
public:
    sample();
    ~sample() { delete &nAmount;}
    int nAmount;
}

推荐答案

否，在堆栈分配的变量上调用 delete 是不安全的.你应该只对 new 创建的东西调用 delete.

No, it is not safe to call delete on a stack-allocated variable. You should only call delete on things created by new.

  • 对于每个 malloc 或 calloc，应该只有一个 free.
  • 对于每个 new，应该恰好有一个 delete.
  • 对于每个 new[]，应该恰好有一个 delete[].
  • 对于每个堆栈分配，不应有明确的释放或删除.在适用的情况下，会自动调用析构函数.
  • For each malloc or calloc, there should be exactly one free.
  • For each new there should be exactly one delete.
  • For each new[] there should be exactly one delete[].
  • For each stack allocation, there should be no explicit freeing or deletion. The destructor is called automatically, where applicable.

一般情况下，您不能混合搭配其中任何一种，例如没有 free-ing 或 delete[]-ing new 对象.这样做会导致未定义的行为.

In general, you cannot mix and match any of these, e.g. no free-ing or delete[]-ing a new object. Doing so results in undefined behavior.

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