char16ptr.h
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// © 2017 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
// char16ptr.h
// created: 2017feb28 Markus W. Scherer
#ifndef __CHAR16PTR_H__
#define __CHAR16PTR_H__
#include "unicode/utypes.h"
#if U_SHOW_CPLUSPLUS_API
#include <cstddef>
#include <string_view>
U_NAMESPACE_BEGIN
#ifdef U_ALIASING_BARRIER
// Use the predefined value.
#elif (defined(__clang__) || defined(__GNUC__)) && U_PLATFORM != U_PF_BROWSER_NATIVE_CLIENT
# define U_ALIASING_BARRIER(ptr) asm volatile("" : : "rm"(ptr) : "memory")
#elif defined(U_IN_DOXYGEN)
# define U_ALIASING_BARRIER(ptr)
#endif
class U_COMMON_API Char16Ptr final {
public:
inline Char16Ptr(char16_t *p);
#if !U_CHAR16_IS_TYPEDEF
inline Char16Ptr(uint16_t *p);
#endif
#if U_SIZEOF_WCHAR_T==2 || defined(U_IN_DOXYGEN)
inline Char16Ptr(wchar_t *p);
#endif
inline Char16Ptr(std::nullptr_t p);
inline ~Char16Ptr();
inline char16_t *get() const;
inline operator char16_t *() const { return get(); }
private:
Char16Ptr() = delete;
#ifdef U_ALIASING_BARRIER
template<typename T> static char16_t *cast(T *t) {
U_ALIASING_BARRIER(t);
return reinterpret_cast<char16_t *>(t);
}
char16_t *p_;
#else
union {
char16_t *cp;
uint16_t *up;
wchar_t *wp;
} u_;
#endif
};
#ifdef U_ALIASING_BARRIER
Char16Ptr::Char16Ptr(char16_t *p) : p_(p) {}
#if !U_CHAR16_IS_TYPEDEF
Char16Ptr::Char16Ptr(uint16_t *p) : p_(cast(p)) {}
#endif
#if U_SIZEOF_WCHAR_T==2
Char16Ptr::Char16Ptr(wchar_t *p) : p_(cast(p)) {}
#endif
Char16Ptr::Char16Ptr(std::nullptr_t p) : p_(p) {}
Char16Ptr::~Char16Ptr() {
U_ALIASING_BARRIER(p_);
}
char16_t *Char16Ptr::get() const { return p_; }
#else
Char16Ptr::Char16Ptr(char16_t *p) { u_.cp = p; }
#if !U_CHAR16_IS_TYPEDEF
Char16Ptr::Char16Ptr(uint16_t *p) { u_.up = p; }
#endif
#if U_SIZEOF_WCHAR_T==2
Char16Ptr::Char16Ptr(wchar_t *p) { u_.wp = p; }
#endif
Char16Ptr::Char16Ptr(std::nullptr_t p) { u_.cp = p; }
Char16Ptr::~Char16Ptr() {}
char16_t *Char16Ptr::get() const { return u_.cp; }
#endif
class U_COMMON_API ConstChar16Ptr final {
public:
inline ConstChar16Ptr(const char16_t *p);
#if !U_CHAR16_IS_TYPEDEF
inline ConstChar16Ptr(const uint16_t *p);
#endif
#if U_SIZEOF_WCHAR_T==2 || defined(U_IN_DOXYGEN)
inline ConstChar16Ptr(const wchar_t *p);
#endif
inline ConstChar16Ptr(const std::nullptr_t p);
inline ~ConstChar16Ptr();
inline const char16_t *get() const;
inline operator const char16_t *() const { return get(); }
private:
ConstChar16Ptr() = delete;
#ifdef U_ALIASING_BARRIER
template<typename T> static const char16_t *cast(const T *t) {
U_ALIASING_BARRIER(t);
return reinterpret_cast<const char16_t *>(t);
}
const char16_t *p_;
#else
union {
const char16_t *cp;
const uint16_t *up;
const wchar_t *wp;
} u_;
#endif
};
#ifdef U_ALIASING_BARRIER
ConstChar16Ptr::ConstChar16Ptr(const char16_t *p) : p_(p) {}
#if !U_CHAR16_IS_TYPEDEF
ConstChar16Ptr::ConstChar16Ptr(const uint16_t *p) : p_(cast(p)) {}
#endif
#if U_SIZEOF_WCHAR_T==2
ConstChar16Ptr::ConstChar16Ptr(const wchar_t *p) : p_(cast(p)) {}
#endif
ConstChar16Ptr::ConstChar16Ptr(const std::nullptr_t p) : p_(p) {}
ConstChar16Ptr::~ConstChar16Ptr() {
U_ALIASING_BARRIER(p_);
}
const char16_t *ConstChar16Ptr::get() const { return p_; }
#else
ConstChar16Ptr::ConstChar16Ptr(const char16_t *p) { u_.cp = p; }
#if !U_CHAR16_IS_TYPEDEF
ConstChar16Ptr::ConstChar16Ptr(const uint16_t *p) { u_.up = p; }
#endif
#if U_SIZEOF_WCHAR_T==2
ConstChar16Ptr::ConstChar16Ptr(const wchar_t *p) { u_.wp = p; }
#endif
ConstChar16Ptr::ConstChar16Ptr(const std::nullptr_t p) { u_.cp = p; }
ConstChar16Ptr::~ConstChar16Ptr() {}
const char16_t *ConstChar16Ptr::get() const { return u_.cp; }
#endif
inline const UChar *toUCharPtr(const char16_t *p) {
#ifdef U_ALIASING_BARRIER
U_ALIASING_BARRIER(p);
#endif
return reinterpret_cast<const UChar *>(p);
}
inline UChar *toUCharPtr(char16_t *p) {
#ifdef U_ALIASING_BARRIER
U_ALIASING_BARRIER(p);
#endif
return reinterpret_cast<UChar *>(p);
}
inline const OldUChar *toOldUCharPtr(const char16_t *p) {
#ifdef U_ALIASING_BARRIER
U_ALIASING_BARRIER(p);
#endif
return reinterpret_cast<const OldUChar *>(p);
}
inline OldUChar *toOldUCharPtr(char16_t *p) {
#ifdef U_ALIASING_BARRIER
U_ALIASING_BARRIER(p);
#endif
return reinterpret_cast<OldUChar *>(p);
}
#ifndef U_FORCE_HIDE_INTERNAL_API
template<typename T>
constexpr bool ConvertibleToU16StringView =
std::is_convertible_v<T, std::u16string_view>
#if !U_CHAR16_IS_TYPEDEF && (!defined(_LIBCPP_VERSION) || _LIBCPP_VERSION < 180000)
|| std::is_convertible_v<T, std::basic_string_view<uint16_t>>
#endif
#if U_SIZEOF_WCHAR_T==2
|| std::is_convertible_v<T, std::wstring_view>
#endif
;
namespace internal {
inline std::u16string_view toU16StringView(std::u16string_view sv) { return sv; }
#if !U_CHAR16_IS_TYPEDEF && (!defined(_LIBCPP_VERSION) || _LIBCPP_VERSION < 180000)
inline std::u16string_view toU16StringView(std::basic_string_view<uint16_t> sv) {
return { ConstChar16Ptr(sv.data()), sv.length() };
}
#endif
#if U_SIZEOF_WCHAR_T==2
inline std::u16string_view toU16StringView(std::wstring_view sv) {
return { ConstChar16Ptr(sv.data()), sv.length() };
}
#endif
template <typename T,
typename = typename std::enable_if_t<!std::is_pointer_v<std::remove_reference_t<T>>>>
inline std::u16string_view toU16StringViewNullable(const T& text) {
return toU16StringView(text);
}
template <typename T,
typename = typename std::enable_if_t<std::is_pointer_v<std::remove_reference_t<T>>>,
typename = void>
inline std::u16string_view toU16StringViewNullable(const T& text) {
if (text == nullptr) return {}; // For backward compatibility.
return toU16StringView(text);
}
} // internal
#endif // U_FORCE_HIDE_INTERNAL_API
U_NAMESPACE_END
#endif /* U_SHOW_CPLUSPLUS_API */
#endif // __CHAR16PTR_H__
U_ALIASING_BARRIER
#define U_ALIASING_BARRIER(ptr)
Barrier for pointer anti-aliasing optimizations even across function boundaries.
Definition char16ptr.h:36
icu::Char16Ptr
char16_t * wrapper with implicit conversion from distinct but bit-compatible pointer types.
Definition char16ptr.h:43
icu::Char16Ptr::Char16Ptr
Char16Ptr(std::nullptr_t p)
nullptr constructor.
icu::Char16Ptr::~Char16Ptr
~Char16Ptr()
Destructor.
icu::Char16Ptr::Char16Ptr
Char16Ptr(uint16_t *p)
Converts the pointer to char16_t *.
icu::Char16Ptr::Char16Ptr
Char16Ptr(wchar_t *p)
Converts the pointer to char16_t *.
icu::Char16Ptr::Char16Ptr
Char16Ptr(char16_t *p)
Copies the pointer.
icu::Char16Ptr::get
char16_t * get() const
Pointer access.
icu::ConstChar16Ptr
const char16_t * wrapper with implicit conversion from distinct but bit-compatible pointer types.
Definition char16ptr.h:150
icu::ConstChar16Ptr::ConstChar16Ptr
ConstChar16Ptr(const char16_t *p)
Copies the pointer.
icu::ConstChar16Ptr::ConstChar16Ptr
ConstChar16Ptr(const uint16_t *p)
Converts the pointer to char16_t *.
icu::ConstChar16Ptr::~ConstChar16Ptr
~ConstChar16Ptr()
Destructor.
icu::ConstChar16Ptr::get
const char16_t * get() const
Pointer access.
icu::ConstChar16Ptr::ConstChar16Ptr
ConstChar16Ptr(const wchar_t *p)
Converts the pointer to char16_t *.
icu::ConstChar16Ptr::ConstChar16Ptr
ConstChar16Ptr(const std::nullptr_t p)
nullptr constructor.
icu::ConvertibleToU16StringView
constexpr bool ConvertibleToU16StringView
Is T convertible to a std::u16string_view or some other 16-bit string view?
Definition char16ptr.h:316
icu::toOldUCharPtr
const OldUChar * toOldUCharPtr(const char16_t *p)
Converts from const char16_t * to const OldUChar *.
Definition char16ptr.h:289
icu::toUCharPtr
const UChar * toUCharPtr(const char16_t *p)
Converts from const char16_t * to const UChar *.
Definition char16ptr.h:261
UChar
char16_t UChar
The base type for UTF-16 code units and pointers.
Definition umachine.h:378
OldUChar
uint16_t OldUChar
Default ICU 58 definition of UChar.
Definition umachine.h:407
utypes.h
Basic definitions for ICU, for both C and C++ APIs.
U_COMMON_API
#define U_COMMON_API
Set to export library symbols from inside the common library, and to import them from outside.
Definition utypes.h:315