Why is it a bad idea to use 'new'? [duplicate]

Answer 1

It's not a "bad idea to use new" -- the poster misstated his case rather badly. Rather, using new and not give you two different things.

new gives you a new, separately allocated instance of the class, and returns a pointer to that instance.

Using the class name without new creates an automatic instance of the class that will go "poof" when it passes out of scope. This "returns" the instance itself, not a pointer (and hence the syntax error in that other thread).

If you use new in the referenced case and added * to pass the compiler, it would result in a leaked object. If, on the other hand, you were passing a parameter to a method that was going to store it somewhere, and you passed a non-newed instance, making it work with &, you'd end up with a dangling pointer stored.