Apple Clang doesn't support C++20 std::format_string

[vyskocil]

When trying to compile the latest code I got the following error, I searched a bit a read that Apple Clang does not support std::format_string from c++20, even when adding the following lines in CMakelists.txt:

set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED YES)

[ 62%] Building CXX object libosmscout/CMakeFiles/OSMScout.dir/src/osmscout/util/Progress.cpp.o
In file included from /Users/vyskocil/Dev/libosmscout-vyskocil/libosmscout/src/osmscout/util/Progress.cpp:20:
/Users/vyskocil/Dev/libosmscout-vyskocil/libosmscout/include/osmscout/util/Progress.h:64:23: error: no template named 'format_string' in namespace 'std'
    void SetStep(std::format_string<Args...> format, Args&& ...args)
                 ~~~~~^
/Users/vyskocil/Dev/libosmscout-vyskocil/libosmscout/include/osmscout/util/Progress.h:70:25: error: no template named 'format_string' in namespace 'std'
    void SetAction(std::format_string<Args...> format, Args&& ...args)
                   ~~~~~^
/Users/vyskocil/Dev/libosmscout-vyskocil/libosmscout/include/osmscout/util/Progress.h:76:21: error: no template named 'format_string' in namespace 'std'
    void Debug(std::format_string<Args...> format, Args&& ...args)
               ~~~~~^
/Users/vyskocil/Dev/libosmscout-vyskocil/libosmscout/include/osmscout/util/Progress.h:82:20: error: no template named 'format_string' in namespace 'std'
    void Info(std::format_string<Args...> format, Args&& ...args)
              ~~~~~^
/Users/vyskocil/Dev/libosmscout-vyskocil/libosmscout/include/osmscout/util/Progress.h:88:23: error: no template named 'format_string' in namespace 'std'
    void Warning(std::format_string<Args...> format, Args&& ...args)
                 ~~~~~^
/Users/vyskocil/Dev/libosmscout-vyskocil/libosmscout/include/osmscout/util/Progress.h:94:21: error: no template named 'format_string' in namespace 'std'
    void Error(std::format_string<Args...> format, Args&& ...args)
               ~~~~~^
/Users/vyskocil/Dev/libosmscout-vyskocil/libosmscout/include/osmscout/util/Progress.h:66:20: error: no member named 'vformat' in namespace 'std'
      SetStep(std::vformat(format.get(), std::make_format_args(args...)));
              ~~~~~^
/Users/vyskocil/Dev/libosmscout-vyskocil/libosmscout/include/osmscout/util/Progress.h:66:47: error: no member named 'make_format_args' in namespace 'std'
      SetStep(std::vformat(format.get(), std::make_format_args(args...)));
                                         ~~~~~^
/Users/vyskocil/Dev/libosmscout-vyskocil/libosmscout/include/osmscout/util/Progress.h:72:28: error: no member named 'vformat' in namespace 'std'
      this->SetAction(std::vformat(format.get(), std::make_format_args(args...)));
                      ~~~~~^
/Users/vyskocil/Dev/libosmscout-vyskocil/libosmscout/include/osmscout/util/Progress.h:72:55: error: no member named 'make_format_args' in namespace 'std'
      this->SetAction(std::vformat(format.get(), std::make_format_args(args...)));
                                                 ~~~~~^
/Users/vyskocil/Dev/libosmscout-vyskocil/libosmscout/include/osmscout/util/Progress.h:78:24: error: no member named 'vformat' in namespace 'std'
      this->Debug(std::vformat(format.get(), std::make_format_args(args...)));
                  ~~~~~^
/Users/vyskocil/Dev/libosmscout-vyskocil/libosmscout/include/osmscout/util/Progress.h:78:51: error: no member named 'make_format_args' in namespace 'std'
      this->Debug(std::vformat(format.get(), std::make_format_args(args...)));
                                             ~~~~~^
/Users/vyskocil/Dev/libosmscout-vyskocil/libosmscout/include/osmscout/util/Progress.h:84:23: error: no member named 'vformat' in namespace 'std'
      this->Info(std::vformat(format.get(), std::make_format_args(args...)));
                 ~~~~~^
/Users/vyskocil/Dev/libosmscout-vyskocil/libosmscout/include/osmscout/util/Progress.h:84:50: error: no member named 'make_format_args' in namespace 'std'
      this->Info(std::vformat(format.get(), std::make_format_args(args...)));
                                            ~~~~~^
/Users/vyskocil/Dev/libosmscout-vyskocil/libosmscout/include/osmscout/util/Progress.h:90:26: error: no member named 'vformat' in namespace 'std'
      this->Warning(std::vformat(format.get(), std::make_format_args(args...)));
                    ~~~~~^
/Users/vyskocil/Dev/libosmscout-vyskocil/libosmscout/include/osmscout/util/Progress.h:90:53: error: no member named 'make_format_args' in namespace 'std'
      this->Warning(std::vformat(format.get(), std::make_format_args(args...)));
                                               ~~~~~^
/Users/vyskocil/Dev/libosmscout-vyskocil/libosmscout/include/osmscout/util/Progress.h:96:24: error: no member named 'vformat' in namespace 'std'
      this->Error(std::vformat(format.get(), std::make_format_args(args...)));
                  ~~~~~^
/Users/vyskocil/Dev/libosmscout-vyskocil/libosmscout/include/osmscout/util/Progress.h:96:51: error: no member named 'make_format_args' in namespace 'std'
      this->Error(std::vformat(format.get(), std::make_format_args(args...)));
                                             ~~~~~^
18 errors generated.

[Karry]

And do you need Import tool? Import library is the only place where progress utility is used. So, as temporary solution may be to move Progress utility there and disable import library and tool build...

Or, it is possible to use latest open-source clang for you?