Is this a proper use of a temporary std::string?

问题

std::string getMyString() { return <make a string>; }

...

HANDLE something = OpenSomething(getMyString().c_str(), ...);

I've read Guaranteed lifetime of temporary in C++ and I believe that the temporary string will live until the assignment has been evaluated, i.e. plenty long enough to make this work as expected.

Having once before run into an std::string lifetime-related bug (can't remember what it was) I'd rather double-check...

回答1:

Yes, this is fine. :-)

The string will be destroyed at the end of the statement, at the semi colon.

回答2:

The destructor for the temporary will not be called until after the function call returns, so what we see here is safe.

However if the called function saves the char* and it ends up being used somehow after OpenSomething has returned, then that's one fine dangling pointer.

回答3:

If you don't use any other argument of OpenSomthing for returning pointer to getMyString.c_str() everything will be OK.

来源：https://stackoverflow.com/questions/5449368/is-this-a-proper-use-of-a-temporary-stdstring