C++:在函数中使用调用者的局部变量安全吗？

Question

我认为最好使用代码示例来描述情况:

int MyFuncA()
{
    MyClass someInstance;
    //<Work with and fill someInstance...>

    MyFuncB( &someInstance )
}

int MyFuncB( MyClass* instance )
{
    //Do anything you could imagine with instance, *except*:
    //* Allowing references to it or any of it's data members to escape this function
    //* Freeing anything the class will free in it's destructor, including itself

    instance->DoThis();
    instance->ModifyThat();
}

下面是我直截了当的问题:

• C 和 C++ 标准是否保证上述概念按预期工作？为什么(不)？
• 谨慎谨慎地执行此操作是否被视为不良做法？

Answer 1

Is the above concept guranteed, by C and C++ standards, to work as expected? Why (not)?

是的，它会按预期工作。 someInstance 在 MyFuncA 范围内可用。对 MyFuncB 的调用在该范围内。

Is this considered doing this, sparingly and with care, bad practice?

不明白为什么。