std string short-string optimization is there a way to find out max short size? [duplicate]

Stroustrup writes that

string is usually implemented using the short-string optimization. That is, short string values are kept in the string object itself and only longer strings are placed on free store. How many characters can a ‘‘short’’ string have? That’s implementation defined, but ‘‘about 14 characters’’ isn’t a bad guess.

But is there a way to find out max "short" string size for my compiler?