Reference of the return value.

Question about reference of the function return object.

class A
{
public:
         std::string getString() const {
                   return str_;
         }

private:
        std:: string str_;
};

function_ref(const A& a){
         ...
         const std::string& str = a.getString(); //getString ()
return 'std::string' not 'const std:string&',
         cout << "Text is: " << str; //use str here will be OK
         ...
}

function_point(const A& a) {
        ...
         const std::string* pStr = &a.getString(); //the return
object of 'std::string' will destruct here
         cout << "Text is: " << *pStr; //so using '*pStr' here may
cause a crash
         ...
}

    My question is if there had any problem with reference of the
function return object, because 'a.getString()' just return a temp
object.
    After I debugged this in VS2003, I found that the temp object will
be destroyed at the end of this function.
    'function_ref(const A& a)' will be running without any problem in
VS2003 but 'function_point(const A& a)' may cause error.

    I want to ask if that reference of a temp return value delay the
destruction is just a property of MS VS2003 or C++ standard.