When iterating over an vector (or other container) of pointers, is there any difference between and/or over advantage using:
for (it = v.begin(); it != v.end(); ++it) {
(*it)->method();
}
or
for (it = v.begin(); it != v.end(); ++it) {
(**it).method();
}
In the C language, there is no difference. However, in C++, the ->
operator can be overloaded, whereas the member selection .
operator cannot.
So in (*foo)->bar
*foo
could designate a class object which acts as a smart pointer, though this won't happen if foo
is an iterator over a standard C++ container of pointers, which means that *foo
evaluates to a pointer.
And in (**foo).bar
, **foo
has to be a class object with a member called bar
(which is accessible).
The unary *
can also be overloaded (which is how the iterator foo
, a class object, returns the object which it references).
In other words, the expressions can diverge in meaning, but if *foo
is a pointer to a class/struct, then the equivalence inherited from the C language applies: (*ptr).member
is equivalent to ptr->member
.