cad/kicad-devel: fix build with libc++ 19HEADmain

As noted in the libc++ 19 release notes [1], std::char_traits<> is now
only provided for char, char8_t, char16_t, char32_t and wchar_t, and any
instantiation for other types will fail.

This causes cad/kicad-devel to fail to compile with clang 19 and libc++
19, resulting in errors similar to:

  /wrkdirs/usr/ports/cad/kicad-devel/work/kicad-6ebd8f46fe24533214b9ed43f1f7e5a4b80dcc71/thirdparty/nanodbc/nanodbc/nanodbc.cpp:261:25: error: implicit instantiation of undefined template 'std::char_traits<unsigned short>'
    261 |     auto const n = std::char_traits<NANODBC_SQLCHAR>::length(array);
        |                         ^
  /usr/include/c++/v1/__string/char_traits.h:45:8: note: template is declared here
     45 | struct char_traits;
        |        ^
  /wrkdirs/usr/ports/cad/kicad-devel/work/kicad-6ebd8f46fe24533214b9ed43f1f7e5a4b80dcc71/thirdparty/nanodbc/nanodbc/nanodbc.cpp:3576:52: error: implicit instantiation of undefined template 'std::char_traits<unsigned short>'
   3576 |             dsn.name = string(&name[0], &name[std::char_traits<NANODBC_SQLCHAR>::length(name)]);
        |                                                    ^
  /usr/include/c++/v1/__string/char_traits.h:45:8: note: template is declared here
     45 | struct char_traits;
        |        ^
  /wrkdirs/usr/ports/cad/kicad-devel/work/kicad-6ebd8f46fe24533214b9ed43f1f7e5a4b80dcc71/thirdparty/nanodbc/nanodbc/nanodbc.cpp:3578:49: error: implicit instantiation of undefined template 'std::char_traits<unsigned short>'
   3578 |                 string(&driver[0], &driver[std::char_traits<NANODBC_SQLCHAR>::length(driver)]);
        |                                                 ^
  /usr/include/c++/v1/__string/char_traits.h:45:8: note: template is declared here
     45 | struct char_traits;
        |        ^
  /wrkdirs/usr/ports/cad/kicad-devel/work/kicad-6ebd8f46fe24533214b9ed43f1f7e5a4b80dcc71/thirdparty/nanodbc/nanodbc/nanodbc.cpp:3629:54: error: implicit instantiation of undefined template 'std::char_traits<unsigned short>'
   3629 |             drv.name = string(&descr[0], &descr[std::char_traits<NANODBC_SQLCHAR>::length(descr)]);
        |                                                      ^
  /usr/include/c++/v1/__string/char_traits.h:45:8: note: template is declared here
     45 | struct char_traits;
        |        ^

and:

  /usr/include/c++/v1/string:820:42: error: implicit instantiation of undefined template 'std::char_traits<unsigned short>'
    820 |   static_assert(is_same<_CharT, typename traits_type::char_type>::value,
        |                                          ^
  /wrkdirs/usr/ports/cad/kicad-devel/work/kicad-6ebd8f46fe24533214b9ed43f1f7e5a4b80dcc71/thirdparty/compoundfilereader/compoundfilereader.h:226:21: note: in instantiation of template class 'std::basic_string<unsigned short>' requested here
    226 |         utf16string dir;
        |                     ^
  /usr/include/c++/v1/__fwd/string.h:23:29: note: template is declared here
     23 | struct _LIBCPP_TEMPLATE_VIS char_traits;
        |                             ^

and:

  /wrkdirs/usr/ports/cad/kicad-devel/work/kicad-6ebd8f46fe24533214b9ed43f1f7e5a4b80dcc71/thirdparty/nlohmann_json/nlohmann/json.hpp:3604:22: error: implicit instantiation of undefined template 'std::char_traits<wxUniChar>'
   3604 | struct char_traits : std::char_traits<T>
        |                      ^
  /wrkdirs/usr/ports/cad/kicad-devel/work/kicad-6ebd8f46fe24533214b9ed43f1f7e5a4b80dcc71/thirdparty/nlohmann_json/nlohmann/json.hpp:6289:14: note: in instantiation of template class 'nlohmann::detail::char_traits<wxUniChar>' requested here
   6289 |     typename char_traits<char_type>::int_type get_character()
        |              ^
  /wrkdirs/usr/ports/cad/kicad-devel/work/kicad-6ebd8f46fe24533214b9ed43f1f7e5a4b80dcc71/thirdparty/nlohmann_json/nlohmann/json.hpp:6465:22: note: in instantiation of template class 'nlohmann::detail::iterator_input_adapter<wxString::const_iterator>' requested here
   6465 |     BaseInputAdapter base_adapter;
        |                      ^
  /wrkdirs/usr/ports/cad/kicad-devel/work/kicad-6ebd8f46fe24533214b9ed43f1f7e5a4b80dcc71/thirdparty/nlohmann_json/nlohmann/json.hpp:23323:16: note: in instantiation of template class 'nlohmann::detail::wide_string_input_adapter<nlohmann::detail::iterator_input_adapter<wxString::const_iterator>, wxUniChar>' requested here
   23323 |         parser(detail::input_adapter(std::forward<InputType>(i)), cb, allow_exceptions, ignore_comments).parse(true, result);
         |                ^
  /wrkdirs/usr/ports/cad/kicad-devel/work/kicad-6ebd8f46fe24533214b9ed43f1f7e5a4b80dcc71/eeschema/sch_io/easyedapro/sch_io_easyedapro.cpp:209:53: note: in instantiation of function template specialization 'nlohmann::basic_json<>::parse<wxString>' requested here
    209 |                 nlohmann::json js = nlohmann::json::parse( txt.ReadLine() );
        |                                                     ^
  /usr/include/c++/v1/__string/char_traits.h:45:8: note: template is declared here
     45 | struct char_traits;
        |        ^

The first batch of errors can be fixed by providing a simple `length()`
function for the `NANODBC_SQLCHAR const*` type. The second batch can be
fixed by using `std::basic_string<char16_t>` for `utf16string`, and
adjusting the call to `std::basic_string<char16_t>::append`. The third
batch can be fixed by adding a `char_traits` definition specifically for
the `wxUniChar` type.

[1] https://libcxx.llvm.org/ReleaseNotes/19.html#deprecations-and-removals

PR:		282512
Approved by:	maintainer timeout (2 weeks)
MFH:		2024Q4

0 files changed, 0 insertions, 0 deletions