// © 2016 and later: Unicode, Inc. and others. // License & terms of use: http://www.unicode.org/copyright.html /* ****************************************************************************** * * Copyright (C) 2002-2012, International Business Machines * Corporation and others. All Rights Reserved. * ****************************************************************************** * file name: uobject.h * encoding: UTF-8 * tab size: 8 (not used) * indentation:4 * * created on: 2002jun26 * created by: Markus W. Scherer */ #ifndef __UOBJECT_H__ #define __UOBJECT_H__ #include "unicode/utypes.h" #if U_SHOW_CPLUSPLUS_API #include "unicode/platform.h" /** * \file * \brief C++ API: Common ICU base class UObject. */ /** * \def U_NO_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 <code>operator new</code> 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. */ #ifndef U_NO_THROW #define U_NO_THROW U_NOEXCEPT #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). * * This is primarily to make it possible and simple to override the * C++ memory management by adding new/delete operators to this base class. * * To override ALL ICU memory management, including that from plain C code, * replace the allocation functions declared in cmemory.h * * UMemory does not contain any virtual functions. * Common "boilerplate" functions are defined in UObject. * * @stable ICU 2.4 */ class U_COMMON_API UMemory { public: /* test versions for debugging shaper heap memory problems */ #ifdef SHAPER_MEMORY_DEBUG static void * NewArray(int size, int count); static void * GrowArray(void * array, int newSize ); static void FreeArray(void * array ); #endif #if U_OVERRIDE_CXX_ALLOCATION /** * Override for ICU4C C++ memory management. * simple, non-class types are allocated using the macros in common/cmemory.h * (uprv_malloc(), uprv_free(), uprv_realloc()); * they or something else could be used here to implement C++ new/delete * for ICU4C C++ classes * @stable ICU 2.4 */ static void * U_EXPORT2 operator new(size_t size) U_NOEXCEPT; /** * Override for ICU4C C++ memory management. * See new(). * @stable ICU 2.4 */ static void * U_EXPORT2 operator new[](size_t size) U_NOEXCEPT; /** * Override for ICU4C C++ memory management. * simple, non-class types are allocated using the macros in common/cmemory.h * (uprv_malloc(), uprv_free(), uprv_realloc()); * they or something else could be used here to implement C++ new/delete * for ICU4C C++ classes * @stable ICU 2.4 */ static void U_EXPORT2 operator delete(void *p) U_NOEXCEPT; /** * Override for ICU4C C++ memory management. * See delete(). * @stable ICU 2.4 */ static void U_EXPORT2 operator delete[](void *p) U_NOEXCEPT; #if U_HAVE_PLACEMENT_NEW /** * Override for ICU4C C++ memory management for STL. * See new(). * @stable ICU 2.6 */ static inline void * U_EXPORT2 operator new(size_t, void *ptr) U_NOEXCEPT { return ptr; } /** * Override for ICU4C C++ memory management for STL. * See delete(). * @stable ICU 2.6 */ static inline void U_EXPORT2 operator delete(void *, void *) U_NOEXCEPT {} #endif /* U_HAVE_PLACEMENT_NEW */ #if U_HAVE_DEBUG_LOCATION_NEW /** * This method overrides the MFC debug version of the operator new * * @param size The requested memory size * @param file The file where the allocation was requested * @param line The line where the allocation was requested */ static void * U_EXPORT2 operator new(size_t size, const char* file, int line) U_NOEXCEPT; /** * This method provides a matching delete for the MFC debug new * * @param p The pointer to the allocated memory * @param file The file where the allocation was requested * @param line The line where the allocation was requested */ static void U_EXPORT2 operator delete(void* p, const char* file, int line) U_NOEXCEPT; #endif /* U_HAVE_DEBUG_LOCATION_NEW */ #endif /* U_OVERRIDE_CXX_ALLOCATION */ /* * Assignment operator not declared. The compiler will provide one * which does nothing since this class does not contain any data members. * API/code coverage may show the assignment operator as present and * untested - ignore. * Subclasses need this assignment operator if they use compiler-provided * assignment operators of their own. An alternative to not declaring one * here would be to declare and empty-implement a protected or public one. UMemory &UMemory::operator=(const UMemory &); */ }; /** * UObject is the common ICU "boilerplate" class. * UObject inherits 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, in particular a virtual destructor. * * The clone() function is not available in UObject because it is not * implemented by all ICU classes. * Many ICU services provide a clone() function for their class trees, * defined on the service's C++ base class * (which itself is a subclass of UObject). * * @stable ICU 2.2 */ class U_COMMON_API UObject : public UMemory { public: /** * Destructor. * * @stable ICU 2.2 */ virtual ~UObject(); /** * 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; protected: // the following functions are protected to prevent instantiation and // direct use of UObject itself // default constructor // inline UObject() {} // copy constructor // inline UObject(const UObject &other) {} #if 0 // TODO Sometime in the future. Implement operator==(). // (This comment inserted in 2.2) // some or all of the following "boilerplate" functions may be made public // in a future ICU4C release when all subclasses implement them // assignment operator // (not virtual, see "Taligent's Guide to Designing Programs" pp.73..74) // commented out because the implementation is the same as a compiler's default // UObject &operator=(const UObject &other) { return *this; } // comparison operators virtual inline UBool operator==(const UObject &other) const { return this==&other; } inline UBool operator!=(const UObject &other) const { return !operator==(other); } // clone() commented out from the base class: // some compilers do not support co-variant return types // (i.e., subclasses would have to return UObject * as well, instead of SubClass *) // see also UObject class documentation. // virtual UObject *clone() const; #endif /* * Assignment operator not declared. The compiler will provide one * which does nothing since this class does not contain any data members. * API/code coverage may show the assignment operator as present and * untested - ignore. * Subclasses need this assignment operator if they use compiler-provided * assignment operators of their own. An alternative to not declaring one * here would be to declare and empty-implement a protected or public one. UObject &UObject::operator=(const UObject &); */ }; #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. * * @param myClass The name of the class that needs RTTI defined. * @internal */ #define UOBJECT_DEFINE_RTTI_IMPLEMENTATION(myClass) \ UClassID U_EXPORT2 myClass::getStaticClassID() { \ static char classID = 0; \ return (UClassID)&classID; \ } \ UClassID myClass::getDynamicClassID() const \ { return myClass::getStaticClassID(); } /** * 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. * * @param myClass The name of the class that needs RTTI defined. * @internal */ #define UOBJECT_DEFINE_ABSTRACT_RTTI_IMPLEMENTATION(myClass) \ UClassID U_EXPORT2 myClass::getStaticClassID() { \ static char classID = 0; \ return (UClassID)&classID; \ } #endif /* U_HIDE_INTERNAL_API */ U_NAMESPACE_END #endif /* U_SHOW_CPLUSPLUS_API */ #endif