c++ - 函数调用中的隐式析构函数执行

Question

我想知道标准对下面这段代码的看法。临时对象的string析构函数能否在调用printPointer之前执行？

附注VS2010 编译器不会提示此代码并且可以正常工作。

void printPointer(const string* pointer)
{
    cout << *pointer << endl;
}

const string* func(const string& s1)
{
    return &s1;
}

int main()
{
    printPointer(func("Hello, World!!!"));
}

Answer 1

Can string destructor of temporary object be executed before calling printPointer?

不，因为临时对象将作为评估包含它们创建点的完整表达式的最后一步被销毁，这意味着它会一直存在，直到调用 printPointer () 结束。

来自标准#12.2/4 Temporary objects[class.temporary] :

Temporary objects are destroyed as the last step in evaluating the full-expression ([intro.execution]) that (lexically) contains the point where they were created.

和#12.2/6 Temporary objects[class.temporary] :

A temporary object bound to a reference parameter in a function call ([expr.call]) persists until the completion of the full-expression containing the call.

explanatory demo