[libc++][format] LWG-3648 format should not print bool with 'c'

[Mordante]

Summary

Note the update of the status table will be done in a separate commit.

[ldionne]

Note the update of the status table will be done in a separate commit.

Why?

[Mordante]

In D119350#3308297, @ldionne wrote:

Note the update of the status table will be done in a separate commit.

Why?

Since the LWG-issue page hasn't been updated yet. This has been accepted during the last plenary. There are some more format related changes that need to be updated after that page is updated. We already format pointers the right way. And there was another LWG-issue that requires no effort. So I want to update these all in one go.

[Mordante]

@ldionne as you mentioned in D119349 I'll commit this with the status update. (I'll wait for approval just to avoid running the CI for a documentation update.)

[ldionne]

Thanks! LGTM with LWG issue updated.

libcxx/docs/Status/Cxx2bIssues.csv

 "`3610 <https://wg21.link/LWG3610>`__","``iota_view::size`` sometimes rejects integer-class types","February 2022","","","|ranges|"
 "`3612 <https://wg21.link/LWG3612>`__","Inconsistent pointer alignment in ``std::format`` ","February 2022","|Complete|","14.0","|format|"
 "`3616 <https://wg21.link/LWG3616>`__","LWG 3498 seems to miss the non-member ``swap`` for ``basic_syncbuf`` ","February 2022","",""
 "`3618 <https://wg21.link/LWG3618>`__","Unnecessary ``iter_move`` for ``transform_view::iterator`` ","February 2022","","","|ranges|"
 "`3619 <https://wg21.link/LWG3619>`__","Specification of ``vformat_to`` contains ill-formed ``formatted_size`` calls","February 2022","|Nothing to do|","","|format|"
 "`3621 <https://wg21.link/LWG3621>`__","Remove feature-test macro ``__cpp_lib_monadic_optional`` ","February 2022","",""
 "`3632 <https://wg21.link/LWG3632>`__","``unique_ptr`` ""Mandates: This constructor is not selected by class tmeplate argument deduction""","February 2022","|Nothing to do|",""
 "`3643 <https://wg21.link/LWG3643>`__","Missing ``constexpr`` in ``std::counted_iterator`` ","February 2022","",""
-"`3648 <https://wg21.link/LWG3648>`__","``format`` should not print ``bool`` with ``'c'`` ","February 2022","","","|format|"
+"`3648 <https://wg21.link/LWG3648>`__","``format`` should not print ``bool`` with ``'c'`` ","February 2022","|Complete|","15.0","|format|"
 "`3649 <https://wg21.link/LWG3649>`__","[fund.ts.v2] Reinstate and bump ``__cpp_lib_experimental_memory_resource`` feature test macro","February 2022","",""
 "`3650 <https://wg21.link/LWG3650>`__","Are ``std::basic_string`` 's ``iterator`` and ``const_iterator`` constexpr iterators?","February 2022","|Nothing to do|",""
 "`3654 <https://wg21.link/LWG3654>`__","``basic_format_context::arg(size_t)`` should be ``noexcept`` ","February 2022","|Complete|","15.0","|format|"
 "`3657 <https://wg21.link/LWG3657>`__","``std::hash<std::filesystem::path>`` is not enabled","February 2022","",""
 "`3660 <https://wg21.link/LWG3660>`__","``iterator_traits<common_iterator>::pointer`` should conform to §[iterator.traits]","February 2022","|Complete|","14.0"
 "`3661 <https://wg21.link/LWG3661>`__","``constinit atomic<shared_ptr<T>> a (nullptr);`` should work","February 2022","",""
 "","","","",""
 `3645 <https://wg21.link/LWG3645>`__,"``resize_and_overwrite`` is overspecified to call its callback with lvalues", "Not voted in","|Complete|","14.0",""
 "","","","",""

libcxx/include/__format/formatter_bool.h

_LIBCPP_HIDE_FROM_ABI constexpr auto parse(auto& __parse_ctx)
     switch (this->__type) {
     case _Flags::_Type::__default:
       this->__type = _Flags::_Type::__string;
       [[fallthrough]];
     case _Flags::_Type::__string:
       this->__handle_bool();
       break;
 
-    case _Flags::_Type::__char:
-      this->__handle_char();
-      break;
-
     case _Flags::_Type::__binary_lower_case:
     case _Flags::_Type::__binary_upper_case:
     case _Flags::_Type::__octal:
     case _Flags::_Type::__decimal:
     case _Flags::_Type::__hexadecimal_lower_case:
     case _Flags::_Type::__hexadecimal_upper_case:
       this->__handle_integer();
       break;

libcxx/test/libcxx/utilities/format/format.string/format.string.std/std_format_spec_bool.pass.cpp

test_exception<Parser<CharT>>(
       "The format-spec should consume the input or end with a '}'", CSTR(".1"));
 
   // *** Locale-specific form ***
   test({.locale_specific_form = true}, 1, CSTR("L}"));
   test({.locale_specific_form = true}, 2, CSTR("Ls}"));
 }
 
 template <class CharT>
-constexpr void test_as_char() {
-
-  test({.type = _Flags::_Type::__char}, 1, CSTR("c}"));
-
-  // *** Align-fill ***
-  test({.alignment = _Flags::_Alignment::__left, .type = _Flags::_Type::__char},
-       2, CSTR("<c}"));
-  test({.alignment = _Flags::_Alignment::__center,
-        .type = _Flags::_Type::__char},
-       2, "^c}");
-  test(
-      {.alignment = _Flags::_Alignment::__right, .type = _Flags::_Type::__char},
-      2, ">c}");
-
-  test({.fill = CharT('L'),
-        .alignment = _Flags::_Alignment::__left,
-        .type = _Flags::_Type::__char},
-       3, CSTR("L<c}"));
-  test({.fill = CharT('#'),
-        .alignment = _Flags::_Alignment::__center,
-        .type = _Flags::_Type::__char},
-       3, CSTR("#^c}"));
-  test({.fill = CharT('0'),
-        .alignment = _Flags::_Alignment::__right,
-        .type = _Flags::_Type::__char},
-       3, CSTR("0>c}"));
-
-  // *** Sign ***
-  test_exception<Parser<CharT>>(
-      "A sign field isn't allowed in this format-spec", CSTR("-c}"));
-
-  // *** Alternate form ***
-  test_exception<Parser<CharT>>(
-      "An alternate form field isn't allowed in this format-spec", CSTR("#c}"));
-
-  // *** Zero padding ***
-  test_exception<Parser<CharT>>(
-      "A zero-padding field isn't allowed in this format-spec", CSTR("0c}"));
-
-  // *** Width ***
-  test({.width = 0, .width_as_arg = false, .type = _Flags::_Type::__char}, 1,
-       CSTR("c}"));
-  test({.width = 1, .width_as_arg = false, .type = _Flags::_Type::__char}, 2,
-       CSTR("1c}"));
-  test({.width = 10, .width_as_arg = false, .type = _Flags::_Type::__char}, 3,
-       CSTR("10c}"));
-  test({.width = 1000, .width_as_arg = false, .type = _Flags::_Type::__char}, 5,
-       CSTR("1000c}"));
-  test({.width = 1000000, .width_as_arg = false, .type = _Flags::_Type::__char},
-       8, CSTR("1000000c}"));
-
-  test({.width = 0, .width_as_arg = true, .type = _Flags::_Type::__char}, 3,
-       CSTR("{}c}"));
-  test({.width = 0, .width_as_arg = true, .type = _Flags::_Type::__char}, 4,
-       CSTR("{0}c}"));
-  test({.width = 1, .width_as_arg = true, .type = _Flags::_Type::__char}, 4,
-       CSTR("{1}c}"));
-
-  // *** Precision ***
-  test_exception<Parser<CharT>>(
-      "The format-spec should consume the input or end with a '}'", CSTR("."));
-  test_exception<Parser<CharT>>(
-      "The format-spec should consume the input or end with a '}'", CSTR(".1"));
-
-  // *** Locale-specific form ***
-  test({.locale_specific_form = true, .type = _Flags::_Type::__char}, 2,
-       CSTR("Lc}"));
-}
-
-template <class CharT>
 constexpr void test_as_integer() {
 
   test({.alignment = _Flags::_Alignment::__right,
         .type = _Flags::_Type::__decimal},
        1, CSTR("d}"));
 
   // *** Align-fill ***
   test({.alignment = _Flags::_Alignment::__left,
constexpr void test() {
   static_assert(!has_precision<decltype(parser)>);
   static_assert(!has_precision_as_arg<decltype(parser)>);
   assert(parser.__locale_specific_form == false);
   assert(parser.__type == _Flags::_Type::__default);
 
   test({}, 0, CSTR("}"));
 
   test_as_string<CharT>();
-  test_as_char<CharT>();
   test_as_integer<CharT>();
 
   // *** Type ***
   {
     const char* expected =
         "The format-spec type has a type not supported for a bool argument";
     test_exception<Parser<CharT>>(expected, CSTR("A}"));
     test_exception<Parser<CharT>>(expected, CSTR("E}"));
     test_exception<Parser<CharT>>(expected, CSTR("F}"));
     test_exception<Parser<CharT>>(expected, CSTR("G}"));
     test_exception<Parser<CharT>>(expected, CSTR("a}"));
+    test_exception<Parser<CharT>>(expected, CSTR("c}"));
     test_exception<Parser<CharT>>(expected, CSTR("e}"));
     test_exception<Parser<CharT>>(expected, CSTR("f}"));
     test_exception<Parser<CharT>>(expected, CSTR("g}"));
     test_exception<Parser<CharT>>(expected, CSTR("p}"));
   }
 
   // **** General ***
   test_exception<Parser<CharT>>(

libcxx/test/std/utilities/format/format.functions/format_tests.h

void format_test_bool(TestFunction check, ExceptionTest check_exception) {
   check_exception("The format-spec should consume the input or end with a '}'", SV("{:.s}"), true);
   check_exception("The format-spec should consume the input or end with a '}'", SV("{:.0s}"), true);
   check_exception("The format-spec should consume the input or end with a '}'", SV("{:.42s}"), true);
 
   // *** locale-specific form ***
   // See locale-specific_form.pass.cpp
 
   // *** type ***
-  for (const auto& fmt : invalid_types<CharT>("bBcdosxX"))
-    check_exception("The format-spec type has a type not supported for a bool argument", fmt, true);
-}
-
-template <class CharT, class TestFunction, class ExceptionTest>
-void format_test_bool_as_char(TestFunction check, ExceptionTest check_exception) {
-  // *** align-fill & width ***
-  check(SV("answer is '\1     '"), SV("answer is '{:6c}'"), true);
-  check(SV("answer is '     \1'"), SV("answer is '{:>6c}'"), true);
-  check(SV("answer is '\1     '"), SV("answer is '{:<6c}'"), true);
-  check(SV("answer is '  \1   '"), SV("answer is '{:^6c}'"), true);
-
-  check(SV("answer is '-----\1'"), SV("answer is '{:->6c}'"), true);
-  check(SV("answer is '\1-----'"), SV("answer is '{:-<6c}'"), true);
-  check(SV("answer is '--\1---'"), SV("answer is '{:-^6c}'"), true);
-
-  check(std::basic_string_view<CharT>(CSTR("answer is '\0     '"), 18), SV("answer is '{:6c}'"), false);
-  check(std::basic_string_view<CharT>(CSTR("answer is '\0     '"), 18), SV("answer is '{:6c}'"), false);
-  check(std::basic_string_view<CharT>(CSTR("answer is '     \0'"), 18), SV("answer is '{:>6c}'"), false);
-  check(std::basic_string_view<CharT>(CSTR("answer is '\0     '"), 18), SV("answer is '{:<6c}'"), false);
-  check(std::basic_string_view<CharT>(CSTR("answer is '  \0   '"), 18), SV("answer is '{:^6c}'"), false);
-
-  check(std::basic_string_view<CharT>(CSTR("answer is '-----\0'"), 18), SV("answer is '{:->6c}'"), false);
-  check(std::basic_string_view<CharT>(CSTR("answer is '\0-----'"), 18), SV("answer is '{:-<6c}'"), false);
-  check(std::basic_string_view<CharT>(CSTR("answer is '--\0---'"), 18), SV("answer is '{:-^6c}'"), false);
-
-  // *** Sign ***
-  check_exception("A sign field isn't allowed in this format-spec", SV("{:-c}"), true);
-  check_exception("A sign field isn't allowed in this format-spec", SV("{:+c}"), true);
-  check_exception("A sign field isn't allowed in this format-spec", SV("{: c}"), true);
-
-  // *** alternate form ***
-  check_exception("An alternate form field isn't allowed in this format-spec", SV("{:#c}"), true);
-
-  // *** zero-padding ***
-  check_exception("A zero-padding field isn't allowed in this format-spec", SV("{:0c}"), true);
-
-  // *** precision ***
-  check_exception("The format-spec should consume the input or end with a '}'", SV("{:.c}"), true);
-  check_exception("The format-spec should consume the input or end with a '}'", SV("{:.0c}"), true);
-  check_exception("The format-spec should consume the input or end with a '}'", SV("{:.42c}"), true);
-
-  // *** locale-specific form ***
-  // Note it has no effect but it's allowed.
-  check(SV("answer is '*'"), SV("answer is '{:Lc}'"), '*');
-
-  // *** type ***
-  for (const auto& fmt : invalid_types<CharT>("bBcdosxX"))
+  for (const auto& fmt : invalid_types<CharT>("bBdosxX"))
     check_exception("The format-spec type has a type not supported for a bool argument", fmt, true);
 }
 
 template <class CharT, class TestFunction, class ExceptionTest>
 void format_test_bool_as_integer(TestFunction check, ExceptionTest check_exception) {
   // *** align-fill & width ***
   check(SV("answer is '1'"), SV("answer is '{:<1d}'"), true);
   check(SV("answer is '1 '"), SV("answer is '{:<2d}'"), true);
// *** Test string format argument ***
     check(SV("hello world"), SV("hello {}"), data);
   }
   format_string_tests<CharT>(check, check_exception);
 
   // *** Test Boolean format argument ***
   check(SV("hello false true"), SV("hello {} {}"), false, true);
 
   format_test_bool<CharT>(check, check_exception);
-  format_test_bool_as_char<CharT>(check, check_exception);
   format_test_bool_as_integer<CharT>(check, check_exception);
 
   // *** Test signed integral format argument ***
   check(SV("hello 42"), SV("hello {}"), static_cast<signed char>(42));
   check(SV("hello 42"), SV("hello {}"), static_cast<short>(42));
   check(SV("hello 42"), SV("hello {}"), static_cast<int>(42));
   check(SV("hello 42"), SV("hello {}"), static_cast<long>(42));
   check(SV("hello 42"), SV("hello {}"), static_cast<long long>(42));