Compilation fails due to the use of deprecated features

[yurivict]

clang-16 default to C++20, and you use the deprecated feature std::char_traits, so the build, fails:

/wrkdirs/usr/ports/databases/nanodbc/work/nanodbc-2.14.0/nanodbc/nanodbc.cpp:263:25: error: 'char_traits<unsigned char>' is deprecated: char_traits<T> for T not equal to char, wchar_t, char8_t, char16_t or char32_t is non-standard and is provided for a temporary period. It will be removed in LLVM 18, so please migrate off of it. [-Werror,-Wdeprecated-declarations]
    auto const n = std::char_traits<NANODBC_SQLCHAR>::length(array);
                        ^
/usr/include/c++/v1/__string/char_traits.h:79:8: note: 'char_traits<unsigned char>' has been explicitly marked deprecated here
struct _LIBCPP_DEPRECATED_("char_traits<T> for T not equal to char, wchar_t, char8_t, char16_t or char32_t is non-standard and is provided for a temporary period. It will be removed in LLVM 18, so please migrate off of it.")
       ^
/usr/include/c++/v1/__config:782:53: note: expanded from macro '_LIBCPP_DEPRECATED_'
#      define _LIBCPP_DEPRECATED_(m) __attribute__((deprecated(m)))
                                                    ^
/wrkdirs/usr/ports/databases/nanodbc/work/nanodbc-2.14.0/nanodbc/nanodbc.cpp:3566:52: error: 'char_traits<unsigned char>' is deprecated: char_traits<T> for T not equal to char, wchar_t, char8_t, char16_t or char32_t is non-standard and is provided for a temporary period. It will be removed in LLVM 18, so please migrate off of it. [-Werror,-Wdeprecated-declarations]
            dsn.name = string(&name[0], &name[std::char_traits<NANODBC_SQLCHAR>::length(name)]);
                                                   ^
/usr/include/c++/v1/__string/char_traits.h:79:8: note: 'char_traits<unsigned char>' has been explicitly marked deprecated here
struct _LIBCPP_DEPRECATED_("char_traits<T> for T not equal to char, wchar_t, char8_t, char16_t or char32_t is non-standard and is provided for a temporary period. It will be removed in LLVM 18, so please migrate off of it.")
       ^
/usr/include/c++/v1/__config:782:53: note: expanded from macro '_LIBCPP_DEPRECATED_'
#      define _LIBCPP_DEPRECATED_(m) __attribute__((deprecated(m)))
                                                    ^
/wrkdirs/usr/ports/databases/nanodbc/work/nanodbc-2.14.0/nanodbc/nanodbc.cpp:3568:49: error: 'char_traits<unsigned char>' is deprecated: char_traits<T> for T not equal to char, wchar_t, char8_t, char16_t or char32_t is non-standard and is provided for a temporary period. It will be removed in LLVM 18, so please migrate off of it. [-Werror,-Wdeprecated-declarations]
                string(&driver[0], &driver[std::char_traits<NANODBC_SQLCHAR>::length(driver)]);
                                                ^
/usr/include/c++/v1/__string/char_traits.h:79:8: note: 'char_traits<unsigned char>' has been explicitly marked deprecated here
struct _LIBCPP_DEPRECATED_("char_traits<T> for T not equal to char, wchar_t, char8_t, char16_t or char32_t is non-standard and is provided for a temporary period. It will be removed in LLVM 18, so please migrate off of it.")

Please replace deprecated features use with valid features, and add the compilation argument that sets the C++ standard level.

FreeBSD 14

[mloskot]

What is your NANODBC_SQLCHAR ?

add the compilation argument that sets the C++ standard level.

Pass your desired via CMAKE_CXX_STANDARD

[jbulow]

This is still an issue: (when compiling with libc++)

/build/nanodbc/nanodbc-2.14.0/nanodbc/nanodbc.cpp:306:25: error: implicit instantiation of undefined template 'std::char_traits<unsigned char>'
  306 |     auto const n = std::char_traits<NANODBC_SQLCHAR>::length(array);
      |                         ^
/usr/local/bin/../include/c++/v1/__string/char_traits.h:44:8: note: template is declared here
   44 | struct char_traits;
      |        ^
/build/nanodbc/nanodbc-2.14.0/nanodbc/nanodbc.cpp:4562:52: error: implicit instantiation of undefined template 'std::char_traits<unsigned char>'
 4562 |             dsn.name = string(&name[0], &name[std::char_traits<NANODBC_SQLCHAR>::length(name)]);
      |                                                    ^
/usr/local/bin/../include/c++/v1/__string/char_traits.h:44:8: note: template is declared here
   44 | struct char_traits;
      |        ^
/build/nanodbc/nanodbc-2.14.0/nanodbc/nanodbc.cpp:4564:49: error: implicit instantiation of undefined template 'std::char_traits<unsigned char>'
 4564 |                 string(&driver[0], &driver[std::char_traits<NANODBC_SQLCHAR>::length(driver)]);
      |                                                 ^
/usr/local/bin/../include/c++/v1/__string/char_traits.h:44:8: note: template is declared here
   44 | struct char_traits;
      |        ^
/build/nanodbc/nanodbc-2.14.0/nanodbc/nanodbc.cpp:4615:54: error: implicit instantiation of undefined template 'std::char_traits<unsigned char>'
 4615 |             drv.name = string(&descr[0], &descr[std::char_traits<NANODBC_SQLCHAR>::length(descr)]);
      |                                                      ^
/usr/local/bin/../include/c++/v1/__string/char_traits.h:44:8: note: template is declared here
   44 | struct char_traits;
      |        ^
4 errors generated.

I guess a solution similar to jtv/libpqxx#751 is needed.