/*
******************************************************************************
*
-* Copyright (C) 2002-2010, International Business Machines
+* Copyright (C) 2002-2012, International Business Machines
* Corporation and others. All Rights Reserved.
*
******************************************************************************
#include "unicode/utypes.h"
-U_NAMESPACE_BEGIN
-
/**
* \file
* \brief C++ API: Common ICU base class UObject.
*/
-/** U_OVERRIDE_CXX_ALLOCATION - Define this to override operator new and
- * delete in UMemory. Enabled by default for ICU.
- *
- * Enabling forces all allocation of ICU object types to use ICU's
- * memory allocation. On Windows, this allows the ICU DLL to be used by
- * applications that statically link the C Runtime library, meaning that
- * the app and ICU will be using different heaps.
- *
- * @stable ICU 2.2
- */
-#ifndef U_OVERRIDE_CXX_ALLOCATION
-#define U_OVERRIDE_CXX_ALLOCATION 1
-#endif
-
-/**
- * \def U_HAVE_PLACEMENT_NEW
- * Define this to define the placement new and
- * delete in UMemory for STL.
- *
- * @stable ICU 2.6
- */
-#ifndef U_HAVE_PLACEMENT_NEW
-#define U_HAVE_PLACEMENT_NEW 1
-#endif
-
-
-/**
- * \def U_HAVE_DEBUG_LOCATION_NEW
- * Define this to define the MFC debug
- * version of the operator new.
- *
- * @stable ICU 3.4
- */
-#ifndef U_HAVE_DEBUG_LOCATION_NEW
-#define U_HAVE_DEBUG_LOCATION_NEW 0
-#endif
-
/**
* @{
* \def U_NO_THROW
* constructor is still called, and if the constructor references member
* data, (which it typically does), the result is a segmentation violation.
*
- * @draft ICU 4.2
- */
+ * @stable ICU 4.2
+ */
#ifndef U_NO_THROW
#define U_NO_THROW throw()
#endif
/** @} */
+/*===========================================================================*/
+/* UClassID-based RTTI */
+/*===========================================================================*/
+
+/**
+ * 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.
+ *
+ * \par
+ * In class hierarchies that implement "poor man's RTTI",
+ * each concrete subclass implements getDynamicClassID() in the same way:
+ *
+ * \code
+ * class Derived {
+ * public:
+ * virtual UClassID getDynamicClassID() const
+ * { return Derived::getStaticClassID(); }
+ * }
+ * \endcode
+ *
+ * Each concrete class implements getStaticClassID() as well, which allows
+ * clients to test for a specific type.
+ *
+ * \code
+ * 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
+ * \endcode
+ * @stable ICU 2.0
+ */
+typedef void* UClassID;
+
+U_NAMESPACE_BEGIN
+
/**
* UMemory is the common ICU base class.
* All other ICU C++ classes are derived from UMemory (starting with ICU 2.4).
* and all other public ICU C++ classes
* are derived from UObject (starting with ICU 2.2).
*
- * UObject contains common virtual functions like for ICU's "poor man's RTTI".
- * It does not contain default implementations of virtual methods
- * like getDynamicClassID to allow derived classes such as Format
- * to declare these as pure virtual.
+ * UObject contains common virtual functions, in particular a virtual destructor.
*
* The clone() function is not available in UObject because it is not
* implemented by all ICU classes.
/**
* ICU4C "poor man's RTTI", returns a UClassID for the actual ICU class.
+ * The base class implementation returns a dummy value.
+ *
+ * Use compiler RTTI rather than ICU's "poor man's RTTI".
+ * Since ICU 4.6, new ICU C++ class hierarchies do not implement "poor man's RTTI".
*
* @stable ICU 2.2
*/
- virtual UClassID getDynamicClassID() const = 0;
+ virtual UClassID getDynamicClassID() const;
protected:
// the following functions are protected to prevent instantiation and
// direct use of UObject itself
// default constructor
- // commented out because UObject is abstract (see getDynamicClassID)
// inline UObject() {}
// copy constructor
- // commented out because UObject is abstract (see getDynamicClassID)
// inline UObject(const UObject &other) {}
#if 0
* here would be to declare and empty-implement a protected or public one.
UObject &UObject::operator=(const UObject &);
*/
-
-// Future implementation for RTTI that support subtyping. [alan]
-//
-// public:
-// /**
-// * @internal
-// */
-// static UClassID getStaticClassID();
-//
-// /**
-// * @internal
-// */
-// UBool instanceOf(UClassID type) const;
};
+#ifndef U_HIDE_INTERNAL_API
/**
* 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.
return (UClassID)&classID; \
}
-/**
- * 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.
- *
- * @param myClass The name of the class that needs RTTI defined.
- * @internal
- */
-#define UOBJECT_DEFINE_NO_RTTI_IMPLEMENTATION(myClass) \
- UClassID myClass::getDynamicClassID() const { return NULL; }
-
-// /**
-// * This macro adds ICU RTTI to an ICU concrete class implementation.
-// * This macro should be invoked in *.cpp files. The corresponding
-// * header should declare getDynamicClassID and getStaticClassID.
-// *
-// * @param myClass The name of the class that needs RTTI defined.
-// * @param myParent The name of the myClass's parent.
-// * @internal
-// */
-/*#define UOBJECT_DEFINE_RTTI_IMPLEMENTATION(myClass, myParent) \
- UOBJECT_DEFINE_ABSTRACT_RTTI_IMPLEMENTATION(myClass, myParent) \
- UClassID myClass::getDynamicClassID() const { \
- return myClass::getStaticClassID(); \
- }
-*/
-
+#endif /* U_HIDE_INTERNAL_API */
U_NAMESPACE_END
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