Function

Files CCore/inc/gadget/Function.h CCore/src/gadget/Function.cpp

Function is a universal, lightweight callback. The last property is essential in the real-time and system programming. Callback means a generalized function pointer. You can call a function or a class method indirectly using a callback.

template <class R,class ... AA>
class Function<R (AA...)>
 {
   ....

  public: 
   
   // constructors

   Function(); // null function

   Function(NothingType); // null function

   Function(R (*func)(AA...)); // callback to the static function

   Function(R (*func)(Handle ctx,AA...),Handle ctx); // callback to the static function with the handle

   template <class T>
   Function(T *obj,R (T::*method)(AA...)); // callback to the method with the object

   // methods

   bool operator + () const; // not null
 
   bool operator ! () const; // is null

   template <class ... TT>
   R operator () (TT && ... tt); // do call
 };

You can bind a Function to a static function, a static function with a handle or an object with a method. Make sure the handle or the object is alive when you do call the function — there is no a life-time control in the Function. The object type must be derived from the Funchor base class.

struct Funchor
 {
  template <class T,class R,class ... AA>
  static Function<R (AA...)> FunctionOf(T *obj,R (T::*method)(AA...)); 
 };

The static method FunctionOf of this class can be used to create a Function object.

There is a non-copyable base type Funchor_nocopy:

using Funchor_nocopy = NoCopyBase<Funchor> ;

The following pattern is used in CCore to work with Functions:

class C : public Funchor
 {
  public:

   void method();

   Function<void (void)> function_method() { return FunctionOf(this,&C::method); }
 };

You may bind virtual methods in Functions, the virtualization is working in such case.