Function return type class c++ book

Im currently working on one of the exercises in the book and i was curious on a different way of returning a value from one of the class functions. Return pointer from functions in c lecture 30 duration. A trailing return type has the advantage that the function s parameters can be used in the specification of the return type. That is a standard way to return objects created inside functions. The return type of an overriding function shall be either identical to the return type of the overridden function or covariant with the classes of the functions. Member function with class type return value object c. So its impossible to have a function that return a type that depend from a value known at runtime.

Functions can return any type supported by c except for arrays and functions, including the pointers, structures and unions which are described in later chapters. Types and typeclasses learn you a haskell for great good. For the types that cant be returned from functions, the restrictions can often be sidestepped by using pointers. In computer programming, the return type or result type defines and constrains the data type of the value returned from a subroutine or method. A pointer to a block of memory is effectively same. The return types are allowed to be different as long as they are covariant. When a class or struct is defined, it becomes a fully qualified type. The return type is the last item in the declaration and the parameters are the first three. If you want to give your function a type declaration but are unsure as to what it should be, you can always just write the function without it and then check it with. Its different if you known the value var at compile time. It can be returned as a new object from a function. Type specifier is optional when declaring a function a. You must specify void in parameters if a function does not have any arguments. Later on well see why theyre all just separated with instead of having some more explicit distinction between the return types and the parameters like int, int, int int or something.