compile error when serialize a more complicate struct to json when using clang 14.0.0-1ubuntu1 on ubuntu 22.04.1LTS

[cagev]

在ubuntu22.04上使用 clang 14 编译 序列化一个更复杂的结构体到json会出现编译错误，
代码直接添加到json_example.cpp里了
https://github.com/cageq/iguana/blob/master/example/json_example.cpp

编译环境 wsl ubuntu 22.04.1 lts
cc --version
Ubuntu clang version 14.0.0-1ubuntu1
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
c++ --version
Ubuntu clang version 14.0.0-1ubuntu1
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin

同样平台切换到gcc (Ubuntu 11.3.0-1ubuntu1~22.04.1) 11.3.0 没有问题， 感觉代码应该没问题，怀疑存在编译器兼容性问题。

编译错误如下：

[ 11%] Built target example
[ 16%] Building CXX object CMakeFiles/json_example.dir/example/json_example.cpp.o
In file included from /home/arthur/work/iguana/example/json_example.cpp:1:
In file included from /home/arthur/work/iguana/iguana/json_reader.hpp:5:
In file included from /home/arthur/work/iguana/iguana/reflection.hpp:23:
/home/arthur/work/iguana/iguana/detail/itoa.hpp:88:28: error: implicit instantiation of undefined template 'dec_::UT<0, 16>'
using U = typename UT<N,2*M,Ts...>::U;
^
/home/arthur/work/iguana/iguana/detail/itoa.hpp:88:28: note: in instantiation of template class 'dec_::UT<0, 8, dec_::MulInv<unsigned long, false, 12379400392853802749, 90>>' requested here
/home/arthur/work/iguana/iguana/detail/itoa.hpp:88:28: note: in instantiation of template class 'dec_::UT<0, 4, dec_::MulInv<unsigned int, false, 3518437209, 45>, dec_::MulInv<unsigned long, false, 12379400392853802749, 90>>' requested here
/home/arthur/work/iguana/iguana/detail/itoa.hpp:88:28: note: in instantiation of template class 'dec_::UT<0, 2, dec_::MulInv<unsigned short, true, 41943, 22>, dec_::MulInv<unsigned int, false, 3518437209, 45>, dec_::MulInv<unsigned long, false, 12379400392853802749, 90>>' requested here
/home/arthur/work/iguana/iguana/detail/itoa.hpp:90:21: note: in instantiation of template class 'dec_::UT<0, 1, dec_::MulInv<unsigned char, false, '\xcd', 11>, dec_::MulInv<unsigned short, true, 41943, 22>, dec_::MulInv<unsigned int, false, 3518437209, 45>, dec_::MulInv<unsigned long, false, 12379400392853802749, 90>>' requested here
template using MI = typename UT<N,1,
^
/home/arthur/work/iguana/iguana/detail/itoa.hpp:96:21: note: in instantiation of template type alias 'MI' requested here
template using U = typename MI::type;
^
/home/arthur/work/iguana/iguana/detail/itoa.hpp:194:51: note: (skipping 1 context in backtrace; use -ftemplate-backtrace-limit=0 to see all)
if (u < pow10<U>(N)) return head(p,U<N/2>(u));
^
/home/arthur/work/iguana/iguana/detail/itoa.hpp:256:38: note: in instantiation of function template specialization 'dec_::convert<dec_::Fwd>::itoa<unsigned char, 1UL>' requested here
p = convert::template itoa(p,u);
^
/home/arthur/work/iguana/iguana/detail/itoa.hpp:265:39: note: in instantiation of function template specialization 'dec_::convert<dec_::Fwd>::itoa<char, 1UL, nullptr>' requested here
return dec_::convert<dec_::Fwd>::itoa(i,p);
^
/home/arthur/work/iguana/iguana/json_writer.hpp:72:12: note: in instantiation of function template specialization 'itoa_fwd' requested here
auto p = itoa_fwd(value, temp);
^
/home/arthur/work/iguana/iguana/json_writer.hpp:262:16: note: in instantiation of function template specialization 'iguana::render_json_value<std::basic_string, char>' requested here
render_json_value(s, t.*v);
^
/home/arthur/work/iguana/example/json_example.cpp:213:11: note: in instantiation of function template specialization 'iguana::to_json<std::basic_string, FieldInfo &>' requested here
iguana::to_json(fieldInfo, ss);
^
/home/arthur/work/iguana/iguana/detail/itoa.hpp:85:41: note: template is declared here
template<int, int, class...> struct UT;
^
/home/arthur/work/iguana/iguana/detail/itoa.hpp:96:21: error: type 'MI<0>' (aka 'int') cannot be used prior to '::' because it has no members
template using U = typename MI::type;
^
/home/arthur/work/iguana/iguana/detail/itoa.hpp:102:9: note: in instantiation of template type alias 'U' requested here
U<N/2> r; // remainder with at most N decimal digits
^
/home/arthur/work/iguana/iguana/detail/itoa.hpp:195:23: note: in instantiation of template class 'dec_::QR<1>' requested here
QR x = split(u);
^
/home/arthur/work/iguana/iguana/detail/itoa.hpp:256:38: note: in instantiation of function template specialization 'dec_::convert<dec_::Fwd>::itoa<unsigned char, 1UL>' requested here
p = convert::template itoa(p,u);
^
/home/arthur/work/iguana/iguana/detail/itoa.hpp:265:39: note: in instantiation of function template specialization 'dec_::convert<dec_::Fwd>::itoa<char, 1UL, nullptr>' requested here
return dec_::convert<dec_::Fwd>::itoa(i,p);
^
/home/arthur/work/iguana/iguana/json_writer.hpp:72:12: note: in instantiation of function template specialization 'itoa_fwd' requested here
auto p = itoa_fwd(value, temp);
^
/home/arthur/work/iguana/iguana/json_writer.hpp:262:16: note: in instantiation of function template specialization 'iguana::render_json_value<std::basic_string, char>' requested here
render_json_value(s, t.*v);
^
/home/arthur/work/iguana/example/json_example.cpp:213:11: note: in instantiation of function template specialization 'iguana::to_json<std::basic_string, FieldInfo &>' requested here
iguana::to_json(fieldInfo, ss);
^
In file included from /home/arthur/work/iguana/example/json_example.cpp:1:
In file included from /home/arthur/work/iguana/iguana/json_reader.hpp:5:
In file included from /home/arthur/work/iguana/iguana/reflection.hpp:23:
/home/arthur/work/iguana/iguana/detail/itoa.hpp:96:21: error: type 'MI<0>' (aka 'int') cannot be used prior to '::' because it has no members
template using U = typename MI::type;
^
/home/arthur/work/iguana/iguana/detail/itoa.hpp:107:21: note: in instantiation of template type alias 'U' requested here
return { q, U<N/2>( u - q * pow10<U<N/2>>(N) ) };
^
/home/arthur/work/iguana/iguana/detail/itoa.hpp:195:23: note: in instantiation of function template specialization 'dec_::split<1UL>' requested here
QR x = split(u);
^
/home/arthur/work/iguana/iguana/detail/itoa.hpp:256:38: note: in instantiation of function template specialization 'dec_::convert<dec_::Fwd>::itoa<unsigned char, 1UL>' requested here
p = convert::template itoa(p,u);
^
/home/arthur/work/iguana/iguana/detail/itoa.hpp:265:39: note: in instantiation of function template specialization 'dec_::convert<dec_::Fwd>::itoa<char, 1UL, nullptr>' requested here
return dec_::convert<dec_::Fwd>::itoa(i,p);
^
/home/arthur/work/iguana/iguana/json_writer.hpp:72:12: note: in instantiation of function template specialization 'itoa_fwd' requested here
auto p = itoa_fwd(value, temp);
^
/home/arthur/work/iguana/iguana/json_writer.hpp:262:16: note: in instantiation of function template specialization 'iguana::render_json_value<std::basic_string, char>' requested here
render_json_value(s, t.*v);
^
/home/arthur/work/iguana/example/json_example.cpp:213:11: note: in instantiation of function template specialization 'iguana::to_json<std::basic_string, FieldInfo &>' requested here
iguana::to_json(fieldInfo, ss);
^
3 errors generated.
make[2]: *** [CMakeFiles/json_example.dir/build.make:76: CMakeFiles/json_example.dir/example/json_example.cpp.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:125: CMakeFiles/json_example.dir/all] Error 2
make: *** [Makefile:101: all] Error 2

[bbbgan]

已经在最新的pr中修复，170

[qicosmos]

已经合并了。