char16ptr.h | Explore in Territory

// © 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>

/**
 * \file
 * \brief C++ API: char16_t pointer wrappers with
 *        implicit conversion from bit-compatible raw pointer types.
 *        Also conversion functions from char16_t * to UChar * and OldUChar *.
 */

U_NAMESPACE_BEGIN

/**
 * \def U_ALIASING_BARRIER
 * Barrier for pointer anti-aliasing optimizations even across function boundaries.
 * @internal
 */
#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) …
#elif defined(U_IN_DOXYGEN)
#define U_ALIASING_BARRIER …
#endif

/**
 * char16_t * wrapper with implicit conversion from distinct but bit-compatible pointer types.
 * @stable ICU 59
 */
class U_COMMON_API Char16Ptr final { … };

/// \cond
#ifdef U_ALIASING_BARRIER

Char16Ptr::Char16Ptr(char16_t *p) : … { … }
#if !U_CHAR16_IS_TYPEDEF
Char16Ptr::Char16Ptr(uint16_t *p) : … { … }
#endif
#if U_SIZEOF_WCHAR_T==2
Char16Ptr::Char16Ptr(wchar_t *p) : p_(cast(p)) {}
#endif
Char16Ptr::Char16Ptr(std::nullptr_t p) : … { … }
Char16Ptr::~Char16Ptr() { … }

char16_t *Char16Ptr::get() const { … }

#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
/// \endcond

/**
 * const char16_t * wrapper with implicit conversion from distinct but bit-compatible pointer types.
 * @stable ICU 59
 */
class U_COMMON_API ConstChar16Ptr final { … };

/// \cond
#ifdef U_ALIASING_BARRIER

ConstChar16Ptr::ConstChar16Ptr(const char16_t *p) : … { … }
#if !U_CHAR16_IS_TYPEDEF
ConstChar16Ptr::ConstChar16Ptr(const uint16_t *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) : … { … }
ConstChar16Ptr::~ConstChar16Ptr() { … }

const char16_t *ConstChar16Ptr::get() const { … }

#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
/// \endcond

/**
 * Converts from const char16_t * to const UChar *.
 * Includes an aliasing barrier if available.
 * @param p pointer
 * @return p as const UChar *
 * @stable ICU 59
 */
inline const UChar *toUCharPtr(const char16_t *p) { … }

/**
 * Converts from char16_t * to UChar *.
 * Includes an aliasing barrier if available.
 * @param p pointer
 * @return p as UChar *
 * @stable ICU 59
 */
inline UChar *toUCharPtr(char16_t *p) { … }

/**
 * Converts from const char16_t * to const OldUChar *.
 * Includes an aliasing barrier if available.
 * @param p pointer
 * @return p as const OldUChar *
 * @stable ICU 59
 */
inline const OldUChar *toOldUCharPtr(const char16_t *p) { … }

/**
 * Converts from char16_t * to OldUChar *.
 * Includes an aliasing barrier if available.
 * @param p pointer
 * @return p as OldUChar *
 * @stable ICU 59
 */
inline OldUChar *toOldUCharPtr(char16_t *p) { … }

#ifndef U_FORCE_HIDE_INTERNAL_API
/**
 * Is T convertible to a std::u16string_view or some other 16-bit string view?
 * @internal
 */
ConvertibleToU16StringView
#endif
#if U_SIZEOF_WCHAR_T==2
    || std::is_convertible_v<T, std::wstring_view>
#endif
    ;

namespace internal {
/**
 * Pass-through overload.
 * @internal
 */
inline std::u16string_view toU16StringView(std::u16string_view sv) { … }

#if !U_CHAR16_IS_TYPEDEF && (!defined(_LIBCPP_VERSION) || _LIBCPP_VERSION < 180000)
/**
 * Basically undefined behavior but sometimes necessary conversion
 * from std::basic_string_view<uint16_t> to std::u16string_view.
 * @internal
 */
inline std::u16string_view toU16StringView(std::basic_string_view<uint16_t> sv) { … }
#endif

#if U_SIZEOF_WCHAR_T==2
/**
 * Basically undefined behavior but sometimes necessary conversion
 * from std::wstring_view to std::u16string_view.
 * @internal
 */
inline std::u16string_view toU16StringView(std::wstring_view sv) {
    return { ConstChar16Ptr(sv.data()), sv.length() };
}
#endif

/**
 * Pass-through overload.
 * @internal
 */
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) { … }

/**
 * In case of nullptr, return an empty view.
 * @internal
 */
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) { … }

}  // internal
#endif  // U_FORCE_HIDE_INTERNAL_API

U_NAMESPACE_END

#endif /* U_SHOW_CPLUSPLUS_API */

#endif  // __CHAR16PTR_H__
godot/thirdparty/icu4c/common/unicode/char16ptr.h
