Typedef C ++, could not solve its meaning

Question

I read this typedef line in a C ++ book, but I could not solve its meaning:

typedef Shape* (*CreateShapeCallBack)();

Now, CreateShapeCallBack means, any idea? Thank.

Answer 1

This is a type of function pointer that returns a pointer to a shape and does not accept any parameters. You can use it as follows:

Shape * Func() {
   // do stuff - return Shape pointer
}

...
CreateShapeCallBack p = Func;

Answer 2

A pointer to a function that returns a pointer to an instance Shape(which is equal Shape*) and accepts voidas a parameter without parameters.

Compare this with, for example, typedef int (*function_pointer)(double);a pointer to a function that takes doubleas a parameter and returns int...

Answer 3

CreateCallBack . .

Answer 4

returntype (*functionpointer)(parameters, ...)

is a function pointer in C ++