Function in C++ returns by value or by reference?

Question

When a function (callee) returns a quantity to the caller function, is it returned by value or by reference?

The thing is I have written a function which builds a ve

Answer 1

All variables defined on the stack are cleaned upon exit. To return a variable you should allocate it on the heap, which you do with the new keyword (or malloc).

Classes and structs are passed around as pointers, while the primitive types are passed around as values.