jpayne@69: // © 2017 and later: Unicode, Inc. and others.
jpayne@69: // License & terms of use: http://www.unicode.org/copyright.html
jpayne@69: 
jpayne@69: // char16ptr.h
jpayne@69: // created: 2017feb28 Markus W. Scherer
jpayne@69: 
jpayne@69: #ifndef __CHAR16PTR_H__
jpayne@69: #define __CHAR16PTR_H__
jpayne@69: 
jpayne@69: #include "unicode/utypes.h"
jpayne@69: 
jpayne@69: #if U_SHOW_CPLUSPLUS_API
jpayne@69: 
jpayne@69: #include <cstddef>
jpayne@69: 
jpayne@69: /**
jpayne@69:  * \file
jpayne@69:  * \brief C++ API: char16_t pointer wrappers with
jpayne@69:  *        implicit conversion from bit-compatible raw pointer types.
jpayne@69:  *        Also conversion functions from char16_t * to UChar * and OldUChar *.
jpayne@69:  */
jpayne@69: 
jpayne@69: U_NAMESPACE_BEGIN
jpayne@69: 
jpayne@69: /**
jpayne@69:  * \def U_ALIASING_BARRIER
jpayne@69:  * Barrier for pointer anti-aliasing optimizations even across function boundaries.
jpayne@69:  * @internal
jpayne@69:  */
jpayne@69: #ifdef U_ALIASING_BARRIER
jpayne@69:     // Use the predefined value.
jpayne@69: #elif (defined(__clang__) || defined(__GNUC__)) && U_PLATFORM != U_PF_BROWSER_NATIVE_CLIENT
jpayne@69: #   define U_ALIASING_BARRIER(ptr) asm volatile("" : : "rm"(ptr) : "memory")
jpayne@69: #elif defined(U_IN_DOXYGEN)
jpayne@69: #   define U_ALIASING_BARRIER(ptr)
jpayne@69: #endif
jpayne@69: 
jpayne@69: /**
jpayne@69:  * char16_t * wrapper with implicit conversion from distinct but bit-compatible pointer types.
jpayne@69:  * @stable ICU 59
jpayne@69:  */
jpayne@69: class U_COMMON_API Char16Ptr U_FINAL {
jpayne@69: public:
jpayne@69:     /**
jpayne@69:      * Copies the pointer.
jpayne@69:      * @param p pointer
jpayne@69:      * @stable ICU 59
jpayne@69:      */
jpayne@69:     inline Char16Ptr(char16_t *p);
jpayne@69: #if !U_CHAR16_IS_TYPEDEF
jpayne@69:     /**
jpayne@69:      * Converts the pointer to char16_t *.
jpayne@69:      * @param p pointer to be converted
jpayne@69:      * @stable ICU 59
jpayne@69:      */
jpayne@69:     inline Char16Ptr(uint16_t *p);
jpayne@69: #endif
jpayne@69: #if U_SIZEOF_WCHAR_T==2 || defined(U_IN_DOXYGEN)
jpayne@69:     /**
jpayne@69:      * Converts the pointer to char16_t *.
jpayne@69:      * (Only defined if U_SIZEOF_WCHAR_T==2.)
jpayne@69:      * @param p pointer to be converted
jpayne@69:      * @stable ICU 59
jpayne@69:      */
jpayne@69:     inline Char16Ptr(wchar_t *p);
jpayne@69: #endif
jpayne@69:     /**
jpayne@69:      * nullptr constructor.
jpayne@69:      * @param p nullptr
jpayne@69:      * @stable ICU 59
jpayne@69:      */
jpayne@69:     inline Char16Ptr(std::nullptr_t p);
jpayne@69:     /**
jpayne@69:      * Destructor.
jpayne@69:      * @stable ICU 59
jpayne@69:      */
jpayne@69:     inline ~Char16Ptr();
jpayne@69: 
jpayne@69:     /**
jpayne@69:      * Pointer access.
jpayne@69:      * @return the wrapped pointer
jpayne@69:      * @stable ICU 59
jpayne@69:      */
jpayne@69:     inline char16_t *get() const;
jpayne@69:     /**
jpayne@69:      * char16_t pointer access via type conversion (e.g., static_cast).
jpayne@69:      * @return the wrapped pointer
jpayne@69:      * @stable ICU 59
jpayne@69:      */
jpayne@69:     inline operator char16_t *() const { return get(); }
jpayne@69: 
jpayne@69: private:
jpayne@69:     Char16Ptr() = delete;
jpayne@69: 
jpayne@69: #ifdef U_ALIASING_BARRIER
jpayne@69:     template<typename T> static char16_t *cast(T *t) {
jpayne@69:         U_ALIASING_BARRIER(t);
jpayne@69:         return reinterpret_cast<char16_t *>(t);
jpayne@69:     }
jpayne@69: 
jpayne@69:     char16_t *p_;
jpayne@69: #else
jpayne@69:     union {
jpayne@69:         char16_t *cp;
jpayne@69:         uint16_t *up;
jpayne@69:         wchar_t *wp;
jpayne@69:     } u_;
jpayne@69: #endif
jpayne@69: };
jpayne@69: 
jpayne@69: /// \cond
jpayne@69: #ifdef U_ALIASING_BARRIER
jpayne@69: 
jpayne@69: Char16Ptr::Char16Ptr(char16_t *p) : p_(p) {}
jpayne@69: #if !U_CHAR16_IS_TYPEDEF
jpayne@69: Char16Ptr::Char16Ptr(uint16_t *p) : p_(cast(p)) {}
jpayne@69: #endif
jpayne@69: #if U_SIZEOF_WCHAR_T==2
jpayne@69: Char16Ptr::Char16Ptr(wchar_t *p) : p_(cast(p)) {}
jpayne@69: #endif
jpayne@69: Char16Ptr::Char16Ptr(std::nullptr_t p) : p_(p) {}
jpayne@69: Char16Ptr::~Char16Ptr() {
jpayne@69:     U_ALIASING_BARRIER(p_);
jpayne@69: }
jpayne@69: 
jpayne@69: char16_t *Char16Ptr::get() const { return p_; }
jpayne@69: 
jpayne@69: #else
jpayne@69: 
jpayne@69: Char16Ptr::Char16Ptr(char16_t *p) { u_.cp = p; }
jpayne@69: #if !U_CHAR16_IS_TYPEDEF
jpayne@69: Char16Ptr::Char16Ptr(uint16_t *p) { u_.up = p; }
jpayne@69: #endif
jpayne@69: #if U_SIZEOF_WCHAR_T==2
jpayne@69: Char16Ptr::Char16Ptr(wchar_t *p) { u_.wp = p; }
jpayne@69: #endif
jpayne@69: Char16Ptr::Char16Ptr(std::nullptr_t p) { u_.cp = p; }
jpayne@69: Char16Ptr::~Char16Ptr() {}
jpayne@69: 
jpayne@69: char16_t *Char16Ptr::get() const { return u_.cp; }
jpayne@69: 
jpayne@69: #endif
jpayne@69: /// \endcond
jpayne@69: 
jpayne@69: /**
jpayne@69:  * const char16_t * wrapper with implicit conversion from distinct but bit-compatible pointer types.
jpayne@69:  * @stable ICU 59
jpayne@69:  */
jpayne@69: class U_COMMON_API ConstChar16Ptr U_FINAL {
jpayne@69: public:
jpayne@69:     /**
jpayne@69:      * Copies the pointer.
jpayne@69:      * @param p pointer
jpayne@69:      * @stable ICU 59
jpayne@69:      */
jpayne@69:     inline ConstChar16Ptr(const char16_t *p);
jpayne@69: #if !U_CHAR16_IS_TYPEDEF
jpayne@69:     /**
jpayne@69:      * Converts the pointer to char16_t *.
jpayne@69:      * @param p pointer to be converted
jpayne@69:      * @stable ICU 59
jpayne@69:      */
jpayne@69:     inline ConstChar16Ptr(const uint16_t *p);
jpayne@69: #endif
jpayne@69: #if U_SIZEOF_WCHAR_T==2 || defined(U_IN_DOXYGEN)
jpayne@69:     /**
jpayne@69:      * Converts the pointer to char16_t *.
jpayne@69:      * (Only defined if U_SIZEOF_WCHAR_T==2.)
jpayne@69:      * @param p pointer to be converted
jpayne@69:      * @stable ICU 59
jpayne@69:      */
jpayne@69:     inline ConstChar16Ptr(const wchar_t *p);
jpayne@69: #endif
jpayne@69:     /**
jpayne@69:      * nullptr constructor.
jpayne@69:      * @param p nullptr
jpayne@69:      * @stable ICU 59
jpayne@69:      */
jpayne@69:     inline ConstChar16Ptr(const std::nullptr_t p);
jpayne@69: 
jpayne@69:     /**
jpayne@69:      * Destructor.
jpayne@69:      * @stable ICU 59
jpayne@69:      */
jpayne@69:     inline ~ConstChar16Ptr();
jpayne@69: 
jpayne@69:     /**
jpayne@69:      * Pointer access.
jpayne@69:      * @return the wrapped pointer
jpayne@69:      * @stable ICU 59
jpayne@69:      */
jpayne@69:     inline const char16_t *get() const;
jpayne@69:     /**
jpayne@69:      * char16_t pointer access via type conversion (e.g., static_cast).
jpayne@69:      * @return the wrapped pointer
jpayne@69:      * @stable ICU 59
jpayne@69:      */
jpayne@69:     inline operator const char16_t *() const { return get(); }
jpayne@69: 
jpayne@69: private:
jpayne@69:     ConstChar16Ptr() = delete;
jpayne@69: 
jpayne@69: #ifdef U_ALIASING_BARRIER
jpayne@69:     template<typename T> static const char16_t *cast(const T *t) {
jpayne@69:         U_ALIASING_BARRIER(t);
jpayne@69:         return reinterpret_cast<const char16_t *>(t);
jpayne@69:     }
jpayne@69: 
jpayne@69:     const char16_t *p_;
jpayne@69: #else
jpayne@69:     union {
jpayne@69:         const char16_t *cp;
jpayne@69:         const uint16_t *up;
jpayne@69:         const wchar_t *wp;
jpayne@69:     } u_;
jpayne@69: #endif
jpayne@69: };
jpayne@69: 
jpayne@69: /// \cond
jpayne@69: #ifdef U_ALIASING_BARRIER
jpayne@69: 
jpayne@69: ConstChar16Ptr::ConstChar16Ptr(const char16_t *p) : p_(p) {}
jpayne@69: #if !U_CHAR16_IS_TYPEDEF
jpayne@69: ConstChar16Ptr::ConstChar16Ptr(const uint16_t *p) : p_(cast(p)) {}
jpayne@69: #endif
jpayne@69: #if U_SIZEOF_WCHAR_T==2
jpayne@69: ConstChar16Ptr::ConstChar16Ptr(const wchar_t *p) : p_(cast(p)) {}
jpayne@69: #endif
jpayne@69: ConstChar16Ptr::ConstChar16Ptr(const std::nullptr_t p) : p_(p) {}
jpayne@69: ConstChar16Ptr::~ConstChar16Ptr() {
jpayne@69:     U_ALIASING_BARRIER(p_);
jpayne@69: }
jpayne@69: 
jpayne@69: const char16_t *ConstChar16Ptr::get() const { return p_; }
jpayne@69: 
jpayne@69: #else
jpayne@69: 
jpayne@69: ConstChar16Ptr::ConstChar16Ptr(const char16_t *p) { u_.cp = p; }
jpayne@69: #if !U_CHAR16_IS_TYPEDEF
jpayne@69: ConstChar16Ptr::ConstChar16Ptr(const uint16_t *p) { u_.up = p; }
jpayne@69: #endif
jpayne@69: #if U_SIZEOF_WCHAR_T==2
jpayne@69: ConstChar16Ptr::ConstChar16Ptr(const wchar_t *p) { u_.wp = p; }
jpayne@69: #endif
jpayne@69: ConstChar16Ptr::ConstChar16Ptr(const std::nullptr_t p) { u_.cp = p; }
jpayne@69: ConstChar16Ptr::~ConstChar16Ptr() {}
jpayne@69: 
jpayne@69: const char16_t *ConstChar16Ptr::get() const { return u_.cp; }
jpayne@69: 
jpayne@69: #endif
jpayne@69: /// \endcond
jpayne@69: 
jpayne@69: /**
jpayne@69:  * Converts from const char16_t * to const UChar *.
jpayne@69:  * Includes an aliasing barrier if available.
jpayne@69:  * @param p pointer
jpayne@69:  * @return p as const UChar *
jpayne@69:  * @stable ICU 59
jpayne@69:  */
jpayne@69: inline const UChar *toUCharPtr(const char16_t *p) {
jpayne@69: #ifdef U_ALIASING_BARRIER
jpayne@69:     U_ALIASING_BARRIER(p);
jpayne@69: #endif
jpayne@69:     return reinterpret_cast<const UChar *>(p);
jpayne@69: }
jpayne@69: 
jpayne@69: /**
jpayne@69:  * Converts from char16_t * to UChar *.
jpayne@69:  * Includes an aliasing barrier if available.
jpayne@69:  * @param p pointer
jpayne@69:  * @return p as UChar *
jpayne@69:  * @stable ICU 59
jpayne@69:  */
jpayne@69: inline UChar *toUCharPtr(char16_t *p) {
jpayne@69: #ifdef U_ALIASING_BARRIER
jpayne@69:     U_ALIASING_BARRIER(p);
jpayne@69: #endif
jpayne@69:     return reinterpret_cast<UChar *>(p);
jpayne@69: }
jpayne@69: 
jpayne@69: /**
jpayne@69:  * Converts from const char16_t * to const OldUChar *.
jpayne@69:  * Includes an aliasing barrier if available.
jpayne@69:  * @param p pointer
jpayne@69:  * @return p as const OldUChar *
jpayne@69:  * @stable ICU 59
jpayne@69:  */
jpayne@69: inline const OldUChar *toOldUCharPtr(const char16_t *p) {
jpayne@69: #ifdef U_ALIASING_BARRIER
jpayne@69:     U_ALIASING_BARRIER(p);
jpayne@69: #endif
jpayne@69:     return reinterpret_cast<const OldUChar *>(p);
jpayne@69: }
jpayne@69: 
jpayne@69: /**
jpayne@69:  * Converts from char16_t * to OldUChar *.
jpayne@69:  * Includes an aliasing barrier if available.
jpayne@69:  * @param p pointer
jpayne@69:  * @return p as OldUChar *
jpayne@69:  * @stable ICU 59
jpayne@69:  */
jpayne@69: inline OldUChar *toOldUCharPtr(char16_t *p) {
jpayne@69: #ifdef U_ALIASING_BARRIER
jpayne@69:     U_ALIASING_BARRIER(p);
jpayne@69: #endif
jpayne@69:     return reinterpret_cast<OldUChar *>(p);
jpayne@69: }
jpayne@69: 
jpayne@69: U_NAMESPACE_END
jpayne@69: 
jpayne@69: #endif /* U_SHOW_CPLUSPLUS_API */
jpayne@69: 
jpayne@69: #endif  // __CHAR16PTR_H__