uobject.h File Reference

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

#include "unicode/utypes.h"
#include "unicode/platform.h"

Go to the source code of this file.

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

Namespaces
	icu
	File coll.h.

Macros
#define	U_NO_THROW   throw()
	Since ICU 64, use U_NOEXCEPT instead. More...
#define	UOBJECT_DEFINE_RTTI_IMPLEMENTATION(myClass)
	This is a simple macro to add ICU RTTI to an ICU object implementation. More...
#define	UOBJECT_DEFINE_ABSTRACT_RTTI_IMPLEMENTATION(myClass)
	This macro adds ICU RTTI to an ICU abstract class implementation. More...

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

Detailed Description

C++ API: Common ICU base class UObject.

Definition in file uobject.h.

Macro Definition Documentation

U_NO_THROW

#define U_NO_THROW   throw()

    Since ICU 64, use U_NOEXCEPT instead.

Previously, define this to define the throw() specification so certain functions do not throw any exceptions

UMemory operator new methods should have the throw() specification appended to them, so that the compiler adds the additional NULL check before calling constructors. Without, if operator new returns NULL the constructor is still called, and if the constructor references member data, (which it typically does), the result is a segmentation violation.

Stable:

ICU 4.2. Since ICU 64, Use U_NOEXCEPT instead. See ICU-20422.

Definition at line 46 of file uobject.h.

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 312 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 295 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.

In class hierarchies that implement "poor man's RTTI", each concrete subclass implements getDynamicClassID() in the same way:

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 93 of file uobject.h.