ICU 75.1 75.1
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localpointer.h
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1// © 2016 and later: Unicode, Inc. and others.
2// License & terms of use: http://www.unicode.org/copyright.html
3/*
4*******************************************************************************
5*
6* Copyright (C) 2009-2016, International Business Machines
7* Corporation and others. All Rights Reserved.
8*
9*******************************************************************************
10* file name: localpointer.h
11* encoding: UTF-8
12* tab size: 8 (not used)
13* indentation:4
14*
15* created on: 2009nov13
16* created by: Markus W. Scherer
17*/
18
19#ifndef __LOCALPOINTER_H__
20#define __LOCALPOINTER_H__
21
41#include "unicode/utypes.h"
42
43#if U_SHOW_CPLUSPLUS_API
44
45#include <memory>
46
47U_NAMESPACE_BEGIN
48
67template<typename T>
69public:
70 // No heap allocation. Use only on the stack.
71 static void* U_EXPORT2 operator new(size_t) = delete;
72 static void* U_EXPORT2 operator new[](size_t) = delete;
73#if U_HAVE_PLACEMENT_NEW
74 static void* U_EXPORT2 operator new(size_t, void*) = delete;
75#endif
76
82 explicit LocalPointerBase(T *p=nullptr) : ptr(p) {}
88 ~LocalPointerBase() { /* delete ptr; */ }
94 UBool isNull() const { return ptr==nullptr; }
100 UBool isValid() const { return ptr!=nullptr; }
108 bool operator==(const T *other) const { return ptr==other; }
116 bool operator!=(const T *other) const { return ptr!=other; }
122 T *getAlias() const { return ptr; }
128 T &operator*() const { return *ptr; }
134 T *operator->() const { return ptr; }
141 T *orphan() {
142 T *p=ptr;
143 ptr=nullptr;
144 return p;
145 }
153 void adoptInstead(T *p) {
154 // delete ptr;
155 ptr=p;
156 }
157protected:
162 T *ptr;
163private:
164 // No comparison operators with other LocalPointerBases.
165 bool operator==(const LocalPointerBase<T> &other) = delete;
166 bool operator!=(const LocalPointerBase<T> &other) = delete;
167 // No ownership sharing: No copy constructor, no assignment operator.
168 LocalPointerBase(const LocalPointerBase<T> &other) = delete;
169 void operator=(const LocalPointerBase<T> &other) = delete;
170};
171
190template<typename T>
192public:
193 using LocalPointerBase<T>::operator*;
194 using LocalPointerBase<T>::operator->;
200 explicit LocalPointer(T *p=nullptr) : LocalPointerBase<T>(p) {}
214 LocalPointer(T *p, UErrorCode &errorCode) : LocalPointerBase<T>(p) {
215 if(p==nullptr && U_SUCCESS(errorCode)) {
217 }
218 }
225 src.ptr=nullptr;
226 }
227
238 explicit LocalPointer(std::unique_ptr<T> &&p)
239 : LocalPointerBase<T>(p.release()) {}
240
258 src.ptr=nullptr;
259 return *this;
260 }
261
270 LocalPointer<T> &operator=(std::unique_ptr<T> &&p) noexcept {
271 adoptInstead(p.release());
272 return *this;
273 }
274
291 friend inline void swap(LocalPointer<T> &p1, LocalPointer<T> &p2) noexcept {
292 p1.swap(p2);
293 }
320 if(U_SUCCESS(errorCode)) {
323 if(p==nullptr) {
325 }
326 } else {
327 delete p;
328 }
329 }
330
342 operator std::unique_ptr<T> () && {
343 return std::unique_ptr<T>(LocalPointerBase<T>::orphan());
344 }
345};
346
365template<typename T>
366class LocalArray : public LocalPointerBase<T> {
367public:
368 using LocalPointerBase<T>::operator*;
369 using LocalPointerBase<T>::operator->;
375 explicit LocalArray(T *p=nullptr) : LocalPointerBase<T>(p) {}
389 LocalArray(T *p, UErrorCode &errorCode) : LocalPointerBase<T>(p) {
390 if(p==nullptr && U_SUCCESS(errorCode)) {
392 }
393 }
402
413 explicit LocalArray(std::unique_ptr<T[]> &&p)
414 : LocalPointerBase<T>(p.release()) {}
415
422 }
433 src.ptr=nullptr;
434 return *this;
435 }
436
445 LocalArray<T> &operator=(std::unique_ptr<T[]> &&p) noexcept {
446 adoptInstead(p.release());
447 return *this;
448 }
449
466 friend inline void swap(LocalArray<T> &p1, LocalArray<T> &p2) noexcept {
467 p1.swap(p2);
468 }
495 if(U_SUCCESS(errorCode)) {
498 if(p==nullptr) {
500 }
501 } else {
502 delete[] p;
503 }
504 }
513
525 operator std::unique_ptr<T[]> () && {
526 return std::unique_ptr<T[]>(LocalPointerBase<T>::orphan());
527 }
528};
529
550#define U_DEFINE_LOCAL_OPEN_POINTER(LocalPointerClassName, Type, closeFunction) \
551 using LocalPointerClassName = internal::LocalOpenPointer<Type, closeFunction>
552
553#ifndef U_IN_DOXYGEN
554namespace internal {
561template <typename Type, auto closeFunction>
562class LocalOpenPointer : public LocalPointerBase<Type> {
563 using LocalPointerBase<Type>::ptr;
564public:
565 using LocalPointerBase<Type>::operator*;
566 using LocalPointerBase<Type>::operator->;
567 explicit LocalOpenPointer(Type *p=nullptr) : LocalPointerBase<Type>(p) {}
568 LocalOpenPointer(LocalOpenPointer &&src) noexcept
569 : LocalPointerBase<Type>(src.ptr) {
570 src.ptr=nullptr;
571 }
572 /* TODO: Be agnostic of the deleter function signature from the user-provided std::unique_ptr? */
573 explicit LocalOpenPointer(std::unique_ptr<Type, decltype(closeFunction)> &&p)
574 : LocalPointerBase<Type>(p.release()) {}
575 ~LocalOpenPointer() { if (ptr != nullptr) { closeFunction(ptr); } }
576 LocalOpenPointer &operator=(LocalOpenPointer &&src) noexcept {
577 if (ptr != nullptr) { closeFunction(ptr); }
578 LocalPointerBase<Type>::ptr=src.ptr;
579 src.ptr=nullptr;
580 return *this;
581 }
582 /* TODO: Be agnostic of the deleter function signature from the user-provided std::unique_ptr? */
583 LocalOpenPointer &operator=(std::unique_ptr<Type, decltype(closeFunction)> &&p) {
584 adoptInstead(p.release());
585 return *this;
586 }
587 void swap(LocalOpenPointer &other) noexcept {
588 Type *temp=LocalPointerBase<Type>::ptr;
589 LocalPointerBase<Type>::ptr=other.ptr;
590 other.ptr=temp;
591 }
592 friend inline void swap(LocalOpenPointer &p1, LocalOpenPointer &p2) noexcept {
593 p1.swap(p2);
594 }
595 void adoptInstead(Type *p) {
596 if (ptr != nullptr) { closeFunction(ptr); }
597 ptr=p;
598 }
599 operator std::unique_ptr<Type, decltype(closeFunction)> () && {
600 return std::unique_ptr<Type, decltype(closeFunction)>(LocalPointerBase<Type>::orphan(), closeFunction);
601 }
602};
603} // namespace internal
604#endif
605
606U_NAMESPACE_END
607
608#endif /* U_SHOW_CPLUSPLUS_API */
609#endif /* __LOCALPOINTER_H__ */
"Smart pointer" class, deletes objects via the C++ array delete[] operator.
LocalArray(T *p=nullptr)
Constructor takes ownership.
LocalArray< T > & operator=(std::unique_ptr< T[]> &&p) noexcept
Move-assign from an std::unique_ptr to this LocalPointer.
T & operator[](ptrdiff_t i) const
Array item access (writable).
~LocalArray()
Destructor deletes the array it owns.
LocalArray(LocalArray< T > &&src) noexcept
Move constructor, leaves src with isNull().
friend void swap(LocalArray< T > &p1, LocalArray< T > &p2) noexcept
Non-member LocalArray swap function.
void adoptInsteadAndCheckErrorCode(T *p, UErrorCode &errorCode)
Deletes the array it owns, and adopts (takes ownership of) the one passed in.
LocalArray< T > & operator=(LocalArray< T > &&src) noexcept
Move assignment operator, leaves src with isNull().
void adoptInstead(T *p)
Deletes the array it owns, and adopts (takes ownership of) the one passed in.
LocalArray(T *p, UErrorCode &errorCode)
Constructor takes ownership and reports an error if nullptr.
void swap(LocalArray< T > &other) noexcept
Swap pointers.
LocalArray(std::unique_ptr< T[]> &&p)
Constructs a LocalArray from a C++11 std::unique_ptr of an array type.
"Smart pointer" base class; do not use directly: use LocalPointer etc.
bool operator!=(const T *other) const
Comparison with a simple pointer, so that existing code with !=nullptr need not be changed.
UBool isValid() const
nullptr check.
T * orphan()
Gives up ownership; the internal pointer becomes nullptr.
UBool isNull() const
nullptr check.
T * ptr
Actual pointer.
LocalPointerBase(T *p=nullptr)
Constructor takes ownership.
T & operator*() const
Access without ownership change.
T * operator->() const
Access without ownership change.
bool operator==(const T *other) const
Comparison with a simple pointer, so that existing code with ==nullptr need not be changed.
void adoptInstead(T *p)
Deletes the object it owns, and adopts (takes ownership of) the one passed in.
T * getAlias() const
Access without ownership change.
~LocalPointerBase()
Destructor deletes the object it owns.
"Smart pointer" class, deletes objects via the standard C++ delete operator.
friend void swap(LocalPointer< T > &p1, LocalPointer< T > &p2) noexcept
Non-member LocalPointer swap function.
LocalPointer< T > & operator=(std::unique_ptr< T > &&p) noexcept
Move-assign from an std::unique_ptr to this LocalPointer.
void adoptInsteadAndCheckErrorCode(T *p, UErrorCode &errorCode)
Deletes the object it owns, and adopts (takes ownership of) the one passed in.
LocalPointer< T > & operator=(LocalPointer< T > &&src) noexcept
Move assignment operator, leaves src with isNull().
LocalPointer(T *p, UErrorCode &errorCode)
Constructor takes ownership and reports an error if nullptr.
LocalPointer(std::unique_ptr< T > &&p)
Constructs a LocalPointer from a C++11 std::unique_ptr.
LocalPointer(T *p=nullptr)
Constructor takes ownership.
void swap(LocalPointer< T > &other) noexcept
Swap pointers.
~LocalPointer()
Destructor deletes the object it owns.
LocalPointer(LocalPointer< T > &&src) noexcept
Move constructor, leaves src with isNull().
void adoptInstead(T *p)
Deletes the object it owns, and adopts (takes ownership of) the one passed in.
U_EXPORT UBool operator==(const StringPiece &x, const StringPiece &y)
Global operator == for StringPiece.
bool operator!=(const StringPiece &x, const StringPiece &y)
Global operator != for StringPiece.
int8_t UBool
The ICU boolean type, a signed-byte integer.
Definition umachine.h:247
Basic definitions for ICU, for both C and C++ APIs.
UErrorCode
Standard ICU4C error code type, a substitute for exceptions.
Definition utypes.h:415
@ U_MEMORY_ALLOCATION_ERROR
Memory allocation error.
Definition utypes.h:458
#define U_SUCCESS(x)
Does the error code indicate success?
Definition utypes.h:728