object - Can I end up with a pointer to an unintended location by passing a pointer to a stack variable to a function in C++? -

i know compiler optimization can result in stack frames volatility. question if safe create stack pointer in c++ , pass function , expect point same object in callee. possible end pointing unintended location because of compiler optimization.

for example safe compiler?

int main(){    std::ofstream f("somefile");    foo(&f);    return 0; } 

or should use heap consistent results.

int main(){    std::ofstream *f=new std::ofstream("somefile");      foo(f);    close(*f);    delete f;    return 0; } 

a dangling pointer created when pointer exists points object who's lifetime has ended:

std::string* s; {     std::string s1("hello");     s = &s1; } // 's' dangling pointer because 's1' has been destructed. 

this situtation not exist in either of posted code snippets, both safe. (though first preferable avoid unnecessary dynamic memory allocation).