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Diffstat (limited to 'intl/icu/source/common/unicode/uobject.h')
| -rw-r--r-- | intl/icu/source/common/unicode/uobject.h | 324 |
1 files changed, 324 insertions, 0 deletions
diff --git a/intl/icu/source/common/unicode/uobject.h b/intl/icu/source/common/unicode/uobject.h new file mode 100644 index 0000000000..f53ec1d111 --- /dev/null +++ b/intl/icu/source/common/unicode/uobject.h @@ -0,0 +1,324 @@ +// © 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 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 nullptr check + * before calling constructors. Without, if <code>operator new</code> returns nullptr 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 noexcept instead. See ICU-20422. + */ +#ifndef U_NO_THROW +#define U_NO_THROW 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) noexcept; + + /** + * Override for ICU4C C++ memory management. + * See new(). + * @stable ICU 2.4 + */ + static void * U_EXPORT2 operator new[](size_t size) 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) noexcept; + + /** + * Override for ICU4C C++ memory management. + * See delete(). + * @stable ICU 2.4 + */ + static void U_EXPORT2 operator delete[](void *p) 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) 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 *) 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) 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) 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 bool operator==(const UObject &other) const { return this==&other; } + inline bool 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 |