ISmartPointer.hpp File Reference

Smart Pointer Design Pattern interface. More...

Classes
class	ISmartPointer
	Tool for managing instances life cycle. More...
class	SmartPointer
	Implementation of the ISmartPointer interface. More...
class	LocalObject
	Local usage of SmartPointer instance. More...

Namespaces
	gatb::core
	Core package of the GATP project.
	gatb::core::system
	Operating System abstraction layer.

Macros
#define	LOCAL(object)   gatb::core::system::LocalObject __##object (object)
#define	SP_SETATTR(a)

Detailed Description

Smart Pointer Design Pattern interface.

Date

01/03/2013

Author

edrezen Define tools for easing life cycle of objects. Also known as smart pointer.

Macro Definition Documentation

#define LOCAL

(

object

)

gatb::core::system::LocalObject __##object (object)

Macro that creates an instance of type LocalObject whose name is the prefix '__' followed by the provided argument.

Sample:

void foo ()
{
   {
      // we create an instance of a class that inherits from SmartPointer
      MyClass* object = new MyClass ();

      // we want that this object lives only inside the including statements block.
      // note that we use the LOCAL macro
      LOCAL (object);
   }

   // Here, the object should have been automatically deleted.
}

See also

LocalObject

#define SP_SETATTR

(

a

)

Value:

{  \
    if (_##a == a)  { return;  }   /* just to be sure that we don't reuse the same object */  \
    if (_##a != 0)  {  _##a->forget (); } \
    _##a = a; \
    if (_##a != 0)  {  _##a->use    (); } \
}

Macro that generates an instructions block that manages life cycle of a class attributes. It is dedicated to simply write clever setter methods.

As a convention, the attribute name must begin by an underscore. Then the provided argument here is the attribute name without this leading underscore.

A typical use of this macro is the following:

• in the constructor, use the default initialization of the attribute as 0
• in the constructor body, use the smart setter with a provided argument
• in the destructor body, use the smart setter with null argument.
• in the private (or protected) part, defines a smart setter for the attribute by using the SP_SETATTR macro

Sample of code:

class MyClass
{
public:
     MyClass (SomeSmartPointerClass* ptr) : _ptr(0)  { setPtr (ptr); }
    ~MyClass ()  { setPtr (0); }
private:
    SomeSmartPointerClass* _ptr;
    void setPtr (SomeSmartPointerClass* ptr)  { SP_SETATTR(ptr); }
};

See also

SmartPointer