C级成员的一生

C类成员的生命周期是多少.例如,何时释放Foo对象的std :: fstream？进入析构函数或离开析构函数时？这是在C标准中定义的吗？

struct Foo
{
    std::fstream mystream;
    ~Foo()
    {
        // wait for thread writing to mystream
    }
};

解决方法

在执行~Foo()的主体之后,在销毁Foo对象期间销毁mystream数据成员. C11§12.4[class.dtor] / 8州：

After executing the body of the destructor and destroying any automatic objects allocated within the body,a destructor for class X calls the destructors for X‘s direct non-variant non-static data members,the destructors for X‘s direct base classes and,if X is the type of the most derived class,its destructor calls the destructors for X‘s virtual base classes.

mystream是Foo的非变体,非静态数据成员(变体数据成员是union的成员; Foo不是union).