typedef question.

I've read that you can use typedef to create a alias of a datatype, as example:
typedef long miles; // define miles as an alias for long

but then I saw this code:

typedef QWidget * (*createModule_t)(QWidget *, const char *, const QXmlAttributes *);
typedef void (*destroyModule_t)(QWidget *);

what happens in these 2 lines?
(QXmlAttributes and QWidget are classes)

The syntax for declaring typedefs is just like initializing objects.

Code:

---

// Pointer to function returning int:
int (*ptr)();

// Alias of 'pointer to a function returning int':
typedef int(*ptr_t)();

---

So in your example, createModule_t is a datatype equivalent to a pointer to a function taking 3 parameters and returning a QWidget*.

destoryModule_t is a datatype equivalent to a pointer to a function taking a QWidget* and returning void.

WNDPROC and THREAD_ENTRY_POINT are some good examples of this.

so that's means that it's a way to make custom datatypes?

Somewhat, though it is more like a way to give new names to existing types.