uobject.h File Reference

C++ API: Common ICU base class UObject. More...

#include "unicode/utypes.h"

Go to the source code of this file.

Data Structures
class	UMemory
	UMemory is the common ICU base class. More...
class	UObject
	UObject is the common ICU "boilerplate" class. More...

Macros
#define	UOBJECT_DEFINE_RTTI_IMPLEMENTATION(myClass)
	This is a simple macro to add ICU RTTI to an ICU object implementation.
#define	UOBJECT_DEFINE_ABSTRACT_RTTI_IMPLEMENTATION(myClass)
	This macro adds ICU RTTI to an ICU abstract class implementation.
#define	UOBJECT_DEFINE_NO_RTTI_IMPLEMENTATION(myClass)
	This is a simple macro to express that a class and its subclasses do not offer ICU's "poor man's RTTI".

Typedefs
typedef void *	UClassID
	UClassID is used to identify classes without using the compiler's RTTI.

Detailed Description

C++ API: Common ICU base class UObject.

Definition in file uobject.h.

Macro Definition Documentation

UOBJECT_DEFINE_ABSTRACT_RTTI_IMPLEMENTATION

#define UOBJECT_DEFINE_ABSTRACT_RTTI_IMPLEMENTATION

(

myClass

)

Value:

    UClassID U_EXPORT2 myClass::getStaticClassID() { \
        static char classID = 0; \
        return (UClassID)&classID; \
    }

This macro adds ICU RTTI to an ICU abstract class implementation.

This macro should be invoked in *.cpp files. The corresponding header should declare getStaticClassID.

Parameters

myClass

The name of the class that needs RTTI defined.

Internal

Do not use. This API is for internal use only.

Definition at line 329 of file uobject.h.

UOBJECT_DEFINE_NO_RTTI_IMPLEMENTATION

#define UOBJECT_DEFINE_NO_RTTI_IMPLEMENTATION

(

myClass

)

Value:

    UClassID myClass::getDynamicClassID() const { return NULL; }

This is a simple macro to express that a class and its subclasses do not offer ICU's "poor man's RTTI".

Beginning with ICU 4.6, ICU requires C++ compiler RTTI. This does not go into the header. This should only be used in *.cpp files. Use this with a private getDynamicClassID() in an immediate subclass of UObject.

Parameters

myClass

The name of the class that needs RTTI defined.

Internal

Do not use. This API is for internal use only.

Definition at line 345 of file uobject.h.

UOBJECT_DEFINE_RTTI_IMPLEMENTATION

#define UOBJECT_DEFINE_RTTI_IMPLEMENTATION

(

myClass

)

Value:

    UClassID U_EXPORT2 myClass::getStaticClassID() { \
        static char classID = 0; \
        return (UClassID)&classID; \
    } \
    UClassID myClass::getDynamicClassID() const \
    { return myClass::getStaticClassID(); }

This is a simple macro to add ICU RTTI to an ICU object implementation.

This does not go into the header. This should only be used in *.cpp files.

Parameters

myClass

The name of the class that needs RTTI defined.

Internal

Do not use. This API is for internal use only.

Definition at line 312 of file uobject.h.

Typedef Documentation

UClassID

typedef void* UClassID

UClassID is used to identify classes without using the compiler's RTTI.

This was used before C++ compilers consistently supported RTTI. ICU 4.6 requires compiler RTTI to be turned on.

Each class hierarchy which needs to implement polymorphic clone() or operator==() defines two methods, described in detail below. UClassID values can be compared using operator==(). Nothing else should be done with them.

getDynamicClassID() is declared in the base class of the hierarchy as a pure virtual. Each concrete subclass implements it in the same way:

class Base {
public:
    virtual UClassID getDynamicClassID() const = 0;
}
 
class Derived {
public:
    virtual UClassID getDynamicClassID() const
      { return Derived::getStaticClassID(); }
}

Each concrete class implements getStaticClassID() as well, which allows clients to test for a specific type.

class Derived {
public:
    static UClassID U_EXPORT2 getStaticClassID();
private:
    static char fgClassID;
}
 
// In Derived.cpp:
UClassID Derived::getStaticClassID()
  { return (UClassID)&Derived::fgClassID; }
char Derived::fgClassID = 0; // Value is irrelevant

Stable

ICU 2.0

Definition at line 96 of file uobject.h.