diff --git a/libcxx/include/__format/formatter_output.h b/libcxx/include/__format/formatter_output.h --- a/libcxx/include/__format/formatter_output.h +++ b/libcxx/include/__format/formatter_output.h @@ -12,6 +12,7 @@ #include <__algorithm/ranges_copy.h> #include <__algorithm/ranges_fill_n.h> +#include <__algorithm/ranges_for_each.h> #include <__algorithm/ranges_transform.h> #include <__chrono/statically_widen.h> #include <__concepts/same_as.h> @@ -503,36 +504,17 @@ __unicode::__code_point_view<_CharT> __view{__values.begin(), __values.end()}; while (!__view.__at_end()) { - auto __first = __view.__position(); - typename __unicode::__consume_p2286_result __result = __view.__consume_p2286(); - if (__result.__ill_formed_size == 0) { - if (!__formatter::__is_escaped_sequence_written(__str, __result.__value, __mark)) + auto __first = __view.__position(); + typename __unicode::__consume_result __result = __view.__consume(); + if (__result.__status == __unicode::__consume_result::__ok) { + if (!__formatter::__is_escaped_sequence_written(__str, __result.__code_point, __mark)) // 2.2.1.3 - Add the character ranges::copy(__first, __view.__position(), std::back_insert_iterator(__str)); - } else { // 2.2.3 sequence of ill-formed code units - // The number of code-units in __result.__value depends on the character type being used. - if constexpr (sizeof(_CharT) == 1) { - _LIBCPP_ASSERT(__result.__ill_formed_size == 1 || __result.__ill_formed_size == 4, - "illegal number of invalid code units."); - if (__result.__ill_formed_size == 1) // ill-formed, one code unit - __formatter::__write_escape_ill_formed_code_unit(__str, __result.__value & 0xff); - else { // out of valid range, four code units - // The code point was properly encoded, decode the value. - __formatter::__write_escape_ill_formed_code_unit(__str, __result.__value >> 18 | 0xf0); - __formatter::__write_escape_ill_formed_code_unit(__str, (__result.__value >> 12 & 0x3f) | 0x80); - __formatter::__write_escape_ill_formed_code_unit(__str, (__result.__value >> 6 & 0x3f) | 0x80); - __formatter::__write_escape_ill_formed_code_unit(__str, (__result.__value & 0x3f) | 0x80); - } - } else if constexpr (sizeof(_CharT) == 2) { - _LIBCPP_ASSERT(__result.__ill_formed_size == 1, "for UTF-16 at most one invalid code unit"); - __formatter::__write_escape_ill_formed_code_unit(__str, __result.__value & 0xffff); - } else { - static_assert(sizeof(_CharT) == 4, "unsupported character width"); - _LIBCPP_ASSERT(__result.__ill_formed_size == 1, "for UTF-32 one code unit is one code point"); - __formatter::__write_escape_ill_formed_code_unit(__str, __result.__value); - } + ranges::for_each(__first, __view.__position(), [&](_CharT __value) { + __formatter::__write_escape_ill_formed_code_unit(__str, __formatter::__to_char32(__value)); + }); } } } diff --git a/libcxx/include/__format/unicode.h b/libcxx/include/__format/unicode.h --- a/libcxx/include/__format/unicode.h +++ b/libcxx/include/__format/unicode.h @@ -31,23 +31,28 @@ namespace __unicode { -# if _LIBCPP_STD_VER >= 23 - -/// The result of consuming a code point using P2286' semantics -/// -/// TODO FMT Combine __consume and __consume_p2286 in one function. -struct __consume_p2286_result { - // A size of 0 means well formed. This to differenciate between - // a valid code point and a code unit that's invalid like 0b11111xxx. - int __ill_formed_size; - - // If well formed the consumed code point. - // Otherwise the ill-formed code units as unsigned 8-bit values. They are - // stored in reverse order, to make it easier to extract the values. - char32_t __value; +// Helper struct for the result of a consume operation. +// +// The status value for a correct code point is 0. This allows a valid value to +// be used without masking. +// When the decoding fails it know the number of code units affected. For the +// current use-cases that value is not needed, therefore it is not stored. +// The escape routine needs the number of code units for both a valid and +// invalid character and keeps track of it itself. Doing it in this result +// unconditionally would give some overhead when the value is unneeded. +struct __consume_result { + // When __status == __ok it contains the decoded code point. + // Else it contains the replacement character U+FFFD + char32_t __code_point : 31; + + enum : char32_t { + // Consumed a well-formed code point. + __ok = 0, + // Encountered invalid UTF-8 + __error = 1 + } __status : 1 {__ok}; }; - -# endif // _LIBCPP_STD_VER >= 23 +static_assert(sizeof(__consume_result) == sizeof(char32_t)); # ifndef _LIBCPP_HAS_NO_UNICODE @@ -66,6 +71,36 @@ inline constexpr char32_t __replacement_character = U'\ufffd'; +// The error of a consume operation. +// +// This sets the code point to the replacement character. This code point does +// not participate in the grapheme clustering, so grapheme clustering code can +// ignore the error status and always use the code point. +inline constexpr __consume_result __consume_result_error{__replacement_character, __consume_result::__error}; + +[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool __is_high_surrogate(char32_t __value) { + return __value >= 0xd800 && __value <= 0xdbff; +} + +[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool __is_low_surrogate(char32_t __value) { + return __value >= 0xdc00 && __value <= 0xdfff; +} + +// https://www.unicode.org/glossary/#surrogate_code_point +[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr bool __is_surrogate(char32_t __value) { + return __value >= 0xd800 && __value <= 0xdfff; +} + +// https://www.unicode.org/glossary/#code_point +[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr bool __is_code_point(char32_t __value) { + return __value <= 0x10ffff; +} + +// https://www.unicode.org/glossary/#unicode_scalar_value +[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr bool __is_scalar_value(char32_t __value) { + return __unicode::__is_code_point(__value) && !__unicode::__is_surrogate(__value); +} + template requires same_as, char> _LIBCPP_HIDE_FROM_ABI constexpr bool __is_continuation(_Iterator __char, int __count) { @@ -97,122 +132,101 @@ _LIBCPP_HIDE_FROM_ABI constexpr bool __at_end() const noexcept { return __first_ == __last_; } _LIBCPP_HIDE_FROM_ABI constexpr _Iterator __position() const noexcept { return __first_; } - _LIBCPP_HIDE_FROM_ABI constexpr char32_t __consume() noexcept { + // https://www.unicode.org/versions/latest/ch03.pdf#G7404 + // Table 3-7, Well-Formed UTF-8 Byte Sequences + // (The remarks column is not part of the original table.) + // Code Points First Byte Second Byte Third Byte Fourth Byte Remarks + // U+0000..U+007F 00..7F + // U+0080..U+07FF *C2*..DF 80..BF U+0000..U0+007F 1 code unit range* + // U+0800..U+0FFF E0 *A0*..BF 80..BF U+0000..U+07FFF 1 and 2 code unit range + // U+1000..U+CFFF E1..EC 80..BF 80..BF + // U+D000..U+D7FF ED 80..*9F* 80..BF U+D800..D+DFFFF surrogate range + // U+E000..U+FFFF EE..EF 80..BF 80..BF + // U+10000..U+3FFFF F0 *90*..BF 80..BF 80..BF U+0000..U+FFFF 1, 2, and 3 code unit range + // U+40000..U+FFFFF F1..F3 80..BF 80..BF 80..BF + // U+100000..U+10FFFF F4 80..*8F* 80..BF 80..BF U+10FFFF..U+1FFFFF invalid range + // + // *Marked* entries are not the full range 80..BF. + // *) This entry is not marked in the Unicode standard, but this entry is also not the full range. + // + // Unlike other parsers, these not valid ranges are tested after decoding. + // - The parser always needs to consume these code units + // - The code is optimized for well-formed UTF-8 + [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr __consume_result __consume() noexcept { _LIBCPP_ASSERT(__first_ != __last_, "can't move beyond the end of input"); // Based on the number of leading 1 bits the number of code units in the // code point can be determined. See // https://en.wikipedia.org/wiki/UTF-8#Encoding - switch (_VSTD::countl_one(static_cast(*__first_))) { + switch (std::countl_one(static_cast(*__first_))) { case 0: - return *__first_++; + return {static_cast(*__first_++)}; - case 2: + case 2: { if (__last_ - __first_ < 2 || !__unicode::__is_continuation(__first_ + 1, 1)) [[unlikely]] break; - else { - char32_t __value = static_cast(*__first_++) & 0x1f; - __value <<= 6; - __value |= static_cast(*__first_++) & 0x3f; - return __value; - } - case 3: - if (__last_ - __first_ < 3 || !__unicode::__is_continuation(__first_ + 1, 2)) [[unlikely]] - break; - else { - char32_t __value = static_cast(*__first_++) & 0x0f; - __value <<= 6; - __value |= static_cast(*__first_++) & 0x3f; - __value <<= 6; - __value |= static_cast(*__first_++) & 0x3f; - return __value; - } + char32_t __value = static_cast(*__first_++) & 0x1f; + __value <<= 6; + __value |= static_cast(*__first_++) & 0x3f; - case 4: - if (__last_ - __first_ < 4 || !__unicode::__is_continuation(__first_ + 1, 3)) [[unlikely]] - break; - else { - char32_t __value = static_cast(*__first_++) & 0x07; - __value <<= 6; - __value |= static_cast(*__first_++) & 0x3f; - __value <<= 6; - __value |= static_cast(*__first_++) & 0x3f; - __value <<= 6; - __value |= static_cast(*__first_++) & 0x3f; - return __value; - } - } - // An invalid number of leading ones can be garbage or a code unit in the - // middle of a code point. By consuming one code unit the parser may get - // "in sync" after a few code units. - ++__first_; - return __replacement_character; - } - -# if _LIBCPP_STD_VER >= 23 - _LIBCPP_HIDE_FROM_ABI constexpr __consume_p2286_result __consume_p2286() noexcept { - _LIBCPP_ASSERT(__first_ != __last_, "can't move beyond the end of input"); + // These values should be encoded in 1 UTF-8 code unit. + if (__value < 0x0080) [[unlikely]] + return __consume_result_error; - // Based on the number of leading 1 bits the number of code units in the - // code point can be determined. See - // https://en.wikipedia.org/wiki/UTF-8#Encoding - switch (std::countl_one(static_cast(*__first_))) { - case 0: - return {0, static_cast(*__first_++)}; + return {__value}; + } - case 2: - if (__last_ - __first_ < 2) [[unlikely]] + case 3: { + if (__last_ - __first_ < 3 || !__unicode::__is_continuation(__first_ + 1, 2)) [[unlikely]] break; - if (__unicode::__is_continuation(__first_ + 1, 1)) { - char32_t __value = static_cast(*__first_++) & 0x1f; - __value <<= 6; - __value |= static_cast(*__first_++) & 0x3f; - return {0, __value}; - } - break; + char32_t __value = static_cast(*__first_++) & 0x0f; + __value <<= 6; + __value |= static_cast(*__first_++) & 0x3f; + __value <<= 6; + __value |= static_cast(*__first_++) & 0x3f; - case 3: - if (__last_ - __first_ < 3) [[unlikely]] - break; + // These values should be encoded in 1 or 2 UTF-8 code units. + if (__value < 0x0800) [[unlikely]] + return __consume_result_error; - if (__unicode::__is_continuation(__first_ + 1, 2)) { - char32_t __value = static_cast(*__first_++) & 0x0f; - __value <<= 6; - __value |= static_cast(*__first_++) & 0x3f; - __value <<= 6; - __value |= static_cast(*__first_++) & 0x3f; - return {0, __value}; - } - break; + // A surrogate value is always encoded in 3 UTF-8 code units. + if (__unicode::__is_surrogate(__value)) [[unlikely]] + return __consume_result_error; + + return {__value}; + } - case 4: - if (__last_ - __first_ < 4) [[unlikely]] + case 4: { + if (__last_ - __first_ < 4 || !__unicode::__is_continuation(__first_ + 1, 3)) [[unlikely]] break; - if (__unicode::__is_continuation(__first_ + 1, 3)) { - char32_t __value = static_cast(*__first_++) & 0x07; - __value <<= 6; - __value |= static_cast(*__first_++) & 0x3f; - __value <<= 6; - __value |= static_cast(*__first_++) & 0x3f; - __value <<= 6; - __value |= static_cast(*__first_++) & 0x3f; + char32_t __value = static_cast(*__first_++) & 0x07; + __value <<= 6; + __value |= static_cast(*__first_++) & 0x3f; + __value <<= 6; + __value |= static_cast(*__first_++) & 0x3f; + __value <<= 6; + __value |= static_cast(*__first_++) & 0x3f; - if (__value > 0x10FFFF) // Outside the valid Unicode range? - return {4, __value}; + // These values should be encoded in 1, 2, or 3 UTF-8 code units. + if (__value < 0x10000) [[unlikely]] + return __consume_result_error; - return {0, __value}; - } - break; + // A value too large is always encoded in 4 UTF-8 code units. + if (!__unicode::__is_code_point(__value)) [[unlikely]] + return __consume_result_error; + + return {__value}; + } } // An invalid number of leading ones can be garbage or a code unit in the // middle of a code point. By consuming one code unit the parser may get // "in sync" after a few code units. - return {1, static_cast(*__first_++)}; + ++__first_; + return __consume_result_error; } -# endif // _LIBCPP_STD_VER >= 23 private: _Iterator __first_; @@ -244,62 +258,33 @@ _LIBCPP_HIDE_FROM_ABI constexpr _Iterator __position() const noexcept { return __first_; } _LIBCPP_HIDE_FROM_ABI constexpr bool __at_end() const noexcept { return __first_ == __last_; } - _LIBCPP_HIDE_FROM_ABI constexpr char32_t __consume() noexcept { + [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr __consume_result __consume() noexcept { _LIBCPP_ASSERT(__first_ != __last_, "can't move beyond the end of input"); + char32_t __value = *__first_++; if constexpr (sizeof(wchar_t) == 2) { - char32_t __result = *__first_++; - // Is the code unit part of a surrogate pair? See - // https://en.wikipedia.org/wiki/UTF-16#U+D800_to_U+DFFF - if (__result >= 0xd800 && __result <= 0xDfff) { - // Malformed Unicode. - if (__first_ == __last_) [[unlikely]] - return __replacement_character; - - __result -= 0xd800; - __result <<= 10; - __result += *__first_++ - 0xdc00; - __result += 0x10000; - } - return __result; + if (__unicode::__is_low_surrogate(__value)) [[unlikely]] + return __consume_result_error; - } else if constexpr (sizeof(wchar_t) == 4) { - char32_t __result = *__first_++; - if (__result > 0x10FFFF) [[unlikely]] - return __replacement_character; - return __result; - } else { - __libcpp_unreachable(); - } - } + if (__unicode::__is_high_surrogate(__value)) { + if (__first_ == __last_ || !__unicode::__is_low_surrogate(*__first_)) [[unlikely]] + return __consume_result_error; -# if _LIBCPP_STD_VER >= 23 - _LIBCPP_HIDE_FROM_ABI constexpr __consume_p2286_result __consume_p2286() noexcept { - _LIBCPP_ASSERT(__first_ != __last_, "can't move beyond the end of input"); + __value -= 0xd800; + __value <<= 10; + __value += *__first_++ - 0xdc00; + __value += 0x10000; - char32_t __result = *__first_++; - if constexpr (sizeof(wchar_t) == 2) { - // https://en.wikipedia.org/wiki/UTF-16#U+D800_to_U+DFFF - if (__is_surrogate_pair_high(__result)) { - // Malformed Unicode. - if (__first_ == __last_ || !__is_surrogate_pair_low(*(__first_ + 1))) [[unlikely]] - return {1, __result}; - - __result -= 0xd800; - __result <<= 10; - __result += *__first_++ - 0xdc00; - __result += 0x10000; - } else if (__is_surrogate_pair_low(__result)) - // A code point shouldn't start with the low surrogate pair - return {1, __result}; + if (!__unicode::__is_code_point(__value)) [[unlikely]] + return __consume_result_error; + } } else { - if (__result > 0x10FFFF) [[unlikely]] - return {1, __result}; + if (!__unicode::__is_scalar_value(__value)) [[unlikely]] + return __consume_result_error; } - return {0, __result}; + return {__value}; } -# endif // _LIBCPP_STD_VER >= 23 private: _Iterator __first_; @@ -399,7 +384,7 @@ public: _LIBCPP_HIDE_FROM_ABI constexpr explicit __extended_grapheme_cluster_view(_Iterator __first, _Iterator __last) : __code_point_view_(__first, __last), - __next_code_point_(__code_point_view_.__consume()), + __next_code_point_(__code_point_view_.__consume().__code_point), __next_prop_(__extended_grapheme_custer_property_boundary::__get_property(__next_code_point_)) {} struct __cluster { @@ -420,6 +405,7 @@ _LIBCPP_ASSERT( __next_prop_ != __extended_grapheme_custer_property_boundary::__property::__eot, "can't move beyond the end of input"); + char32_t __code_point = __next_code_point_; if (!__code_point_view_.__at_end()) return {__code_point, __get_break()}; @@ -444,7 +430,7 @@ __next_prop_ = __extended_grapheme_custer_property_boundary::__property::__eot; return __result; } - __next_code_point_ = __code_point_view_.__consume(); + __next_code_point_ = __code_point_view_.__consume().__code_point; __next_prop_ = __extended_grapheme_custer_property_boundary::__get_property(__next_code_point_); __has_extened_pictographic |= @@ -474,18 +460,10 @@ _LIBCPP_HIDE_FROM_ABI constexpr bool __at_end() const noexcept { return __first_ == __last_; } _LIBCPP_HIDE_FROM_ABI constexpr _Iterator __position() const noexcept { return __first_; } - _LIBCPP_HIDE_FROM_ABI constexpr char32_t __consume() noexcept { + [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr __consume_result __consume() noexcept { _LIBCPP_ASSERT(__first_ != __last_, "can't move beyond the end of input"); - return *__first_++; - } - -# if _LIBCPP_STD_VER >= 23 - _LIBCPP_HIDE_FROM_ABI constexpr __consume_p2286_result __consume_p2286() noexcept { - _LIBCPP_ASSERT(__first_ != __last_, "can't move beyond the end of input"); - - return {0, std::make_unsigned_t<_CharT>(*__first_++)}; + return {static_cast(*__first_++)}; } -# endif // _LIBCPP_STD_VER >= 23 private: _Iterator __first_; diff --git a/libcxx/test/std/utilities/format/format.functions/escaped_output.unicode.pass.cpp b/libcxx/test/std/utilities/format/format.functions/escaped_output.unicode.pass.cpp --- a/libcxx/test/std/utilities/format/format.functions/escaped_output.unicode.pass.cpp +++ b/libcxx/test/std/utilities/format/format.functions/escaped_output.unicode.pass.cpp @@ -202,14 +202,9 @@ test_format(V{L"'\\u{600}'"}, L"{:?}", L'\x600'); // ARABIC NUMBER SIGN test_format(V{L"'\\u{feff}'"}, L"{:?}", L'\xfeff'); // ZERO WIDTH NO-BREAK SPACE - if constexpr (sizeof(CharT) == 2) { - // Incomplete surrogate pair in UTF-16 - test_format(V{L"'\\x{d800}'"}, L"{:?}", L'\xd800'); // - test_format(V{L"'\\x{dfff}'"}, L"{:?}", L'\xdfff'); // - } else { - test_format(V{L"'\\u{d800}'"}, L"{:?}", L'\xd800'); // - test_format(V{L"'\\u{dfff}'"}, L"{:?}", L'\xdfff'); // - } + // Incomplete surrogate pair in UTF-16 + test_format(V{L"'\\x{d800}'"}, L"{:?}", L'\xd800'); // + test_format(V{L"'\\x{dfff}'"}, L"{:?}", L'\xdfff'); // // Private_Use test_format(V{L"'\\u{e000}'"}, L"{:?}", L'\xe000'); // @@ -277,6 +272,48 @@ // Ill-formend UTF-8 test_format(SV(R"(["\x{c3}"])"), SV("[{:?}]"), "\xc3"); test_format(SV(R"(["\x{c3}("])"), SV("[{:?}]"), "\xc3\x28"); + + /* U+0000..U+0007F 1 code unit range, encoded in 2 code units. */ + test_format(SV(R"(["\x{c0}\x{80}"])"), SV("[{:?}]"), "\xc0\x80"); // U+0000 + test_format(SV(R"(["\x{c1}\x{bf}"])"), SV("[{:?}]"), "\xc1\xbf"); // U+007F + test_format(SV(R"(["\u{80}"])"), SV("[{:?}]"), "\xc2\x80"); // U+0080 first valid (General_Category=Control) + + /* U+0000..U+07FFF 1 and 2 code unit range, encoded in 3 code units. */ + test_format(SV(R"(["\x{e0}\x{80}\x{80}"])"), SV("[{:?}]"), "\xe0\x80\x80"); // U+0000 + test_format(SV(R"(["\x{e0}\x{81}\x{bf}"])"), SV("[{:?}]"), "\xe0\x81\xbf"); // U+007F + test_format(SV(R"(["\x{e0}\x{82}\x{80}"])"), SV("[{:?}]"), "\xe0\x82\x80"); // U+0080 + test_format(SV(R"(["\x{e0}\x{9f}\x{bf}"])"), SV("[{:?}]"), "\xe0\x9f\xbf"); // U+07FF + test_format(SV("[\"\u0800\"]"), SV("[{:?}]"), "\xe0\xa0\x80"); // U+0800 first valid + +#if 0 + // This code point is in the Hangul Jamo Extended-B block and at the time of writing + // it's unassigned. When it comes defined, this branch might become true. + test_format(SV("[\"\ud7ff\"]"), SV("[{:?}]"), "\xed\x9f\xbf"); // U+D7FF last valid +#else + /* U+D800..D+DFFFF surrogate range */ + test_format(SV(R"(["\u{d7ff}"])"), SV("[{:?}]"), "\xed\x9f\xbf"); // U+D7FF last valid +#endif + test_format(SV(R"(["\x{ed}\x{a0}\x{80}"])"), SV("[{:?}]"), "\xed\xa0\x80"); // U+D800 + test_format(SV(R"(["\x{ed}\x{af}\x{bf}"])"), SV("[{:?}]"), "\xed\xaf\xbf"); // U+DBFF + test_format(SV(R"(["\x{ed}\x{bf}\x{80}"])"), SV("[{:?}]"), "\xed\xbf\x80"); // U+DC00 + test_format(SV(R"(["\x{ed}\x{bf}\x{bf}"])"), SV("[{:?}]"), "\xed\xbf\xbf"); // U+DFFF + test_format(SV(R"(["\u{e000}"])"), SV("[{:?}]"), "\xee\x80\x80"); // U+E000 first valid + // (in the Private Use Area block) + + /* U+0000..U+FFFF 1, 2, and 3 code unit range */ + test_format(SV(R"(["\x{f0}\x{80}\x{80}\x{80}"])"), SV("[{:?}]"), "\xf0\x80\x80\x80"); // U+0000 + test_format(SV(R"(["\x{f0}\x{80}\x{81}\x{bf}"])"), SV("[{:?}]"), "\xf0\x80\x81\xbf"); // U+007F + test_format(SV(R"(["\x{f0}\x{80}\x{82}\x{80}"])"), SV("[{:?}]"), "\xf0\x80\x82\x80"); // U+0080 + test_format(SV(R"(["\x{f0}\x{80}\x{9f}\x{bf}"])"), SV("[{:?}]"), "\xf0\x80\x9f\xbf"); // U+07FF + test_format(SV(R"(["\x{f0}\x{80}\x{a0}\x{80}"])"), SV("[{:?}]"), "\xf0\x80\xa0\x80"); // U+0800 + test_format(SV(R"(["\x{f0}\x{8f}\x{bf}\x{bf}"])"), SV("[{:?}]"), "\xf0\x8f\xbf\xbf"); // U+FFFF + test_format(SV("[\"\U00010000\"]"), SV("[{:?}]"), "\xf0\x90\x80\x80"); // U+10000 first valid + + /* U+10FFFF..U+1FFFFF invalid range */ + test_format(SV(R"(["\u{10ffff}"])"), SV("[{:?}]"), "\xf4\x8f\xbf\xbf"); // U+10FFFF last valid + // (in Supplementary Private Use Area-B) + test_format(SV(R"(["\x{f4}\x{90}\x{80}\x{80}"])"), SV("[{:?}]"), "\xf4\x90\x80\x80"); // U+110000 + test_format(SV(R"(["\x{f4}\x{bf}\x{bf}\x{bf}"])"), SV("[{:?}]"), "\xf4\xbf\xbf\xbf"); // U+11FFFF } else { // Valid UTF-16 and UTF-32 test_format(SV("[\"\u00c3\"]"), SV("[{:?}]"), L"\xc3"); // LATIN CAPITAL LETTER A WITH TILDE @@ -320,11 +357,8 @@ // Format test_format(V{LR"("\u{ad}\u{600}\u{feff}")"}, L"{:?}", L"\xad\x600\xfeff"); - if constexpr (sizeof(CharT) == 2) - // Incomplete surrogate pair in UTF-16 - test_format(V{LR"("\x{d800}")"}, L"{:?}", L"\xd800"); - else - test_format(V{LR"("\u{d800}")"}, L"{:?}", L"\xd800"); + // Incomplete surrogate pair in UTF-16 + test_format(V{LR"("\x{d800}")"}, L"{:?}", L"\xd800"); // Private_Use test_format(V{LR"("\u{e000}\u{f8ff}")"}, L"{:?}", L"\xe000\xf8ff");