class contains c array, compilation error is reported

[huqin-RM]

class Ctest
{
public:
double m_vdMat[3][3];
};

PYBIND11_EMBEDDED_MODULE(fast_calc,m){
py::class_(m, "Ctest")
.def(py::init<>())
.def_readwrite("m_vdMat", &CIntrinsicsM::m_vdMat);

}

/usr/local/include/pybind11/pybind11.h:1717:56: error: invalid array assignment
1717 | fset([pm](type &c, const D &value) { c.pm = value; }, is_method(this));
| ~~~~~~^~~~~~~
/usr/local/include/pybind11/pybind11.h: In instantiation of ‘void pybind11::cpp_function::initialize(Func&&, Return ()(Args ...), const Extra& ...) [with Func = pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]::<lambda(const type&)>; Return = const double (&)[3][3]; Args = {const Ctest&}; Extra = {pybind11::is_method}]’:
/usr/local/include/pybind11/pybind11.h:145:9: required from ‘pybind11::cpp_function::cpp_function(Func&&, const Extra& ...) [with Func = pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]::<lambda(const type&)>; Extra = {pybind11::is_method}; = void]’
/usr/local/include/pybind11/pybind11.h:1716:22: required from ‘pybind11::class_<type_, options>& pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]’
1.cpp:150:54: required from here
/usr/local/include/pybind11/pybind11.h:296:40: error: no matching function for call to ‘pybind11::detail::type_caster<double, void>::cast(const double [3][3], pybind11::return_value_policy&, pybind11::handle&)’
296 | result = cast_out::cast(
| ~~~~~~~~~~~~~~^
297 | std::move(args_converter).template call<Return, Guard>(cap->f),
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
298 | policy,
| ~~~~~~~
299 | call.parent);
| ~~~~~~~~~~~~
In file included from /usr/local/include/pybind11/attr.h:14,
from /usr/local/include/pybind11/detail/class.h:12,
from /usr/local/include/pybind11/pybind11.h:13,
from /usr/local/include/pybind11/embed.h:12,
from 1.cpp:1:
/usr/local/include/pybind11/cast.h:208:5: note: candidate: ‘template static typename std::enable_if<std::is_floating_point::value, pybind11::handle>::type pybind11::detail::type_caster<T, typename std::enable_if<(std::is_arithmetic<_Tp>::value && (! pybind11::detail::negation<std::is_same<pybind11::detail::bools<pybind11::detail::negation<std::is_same<CharT, char> >::value, pybind11::detail::negation<std::is_same<CharT, char16_t> >::value, pybind11::detail::negation<std::is_same<CharT, char32_t> >::value, pybind11::detail::negation<std::is_same<CharT, wchar_t> >::value, true>, pybind11::detail::bools<true, pybind11::detail::negation<std::is_same<CharT, char> >::value, pybind11::detail::negation<std::is_same<CharT, char16_t> >::value, pybind11::detail::negation<std::is_same<CharT, char32_t> >::value, pybind11::detail::negation<std::is_same<CharT, wchar_t> >::value> > >::value)), void>::type>::cast(U, pybind11::return_value_policy, pybind11::handle) [with U = U; T = double]’
208 | cast(U src, return_value_policy / policy /, handle / parent /) {
| ^~~~
/usr/local/include/pybind11/cast.h:208:5: note: template argument deduction/substitution failed:
/usr/local/include/pybind11/cast.h: In substitution of ‘template static typename std::enable_if<std::is_floating_point<_Tp>::value, pybind11::handle>::type pybind11::detail::type_caster<double, void>::cast(U, pybind11::return_value_policy, pybind11::handle) [with U = const double ()[3]]’:
/usr/local/include/pybind11/pybind11.h:296:40: required from ‘void pybind11::cpp_function::initialize(Func&&, Return ()(Args ...), const Extra& ...) [with Func = pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]::<lambda(const type&)>; Return = const double (&)[3][3]; Args = {const Ctest&}; Extra = {pybind11::is_method}]’
/usr/local/include/pybind11/pybind11.h:145:9: required from ‘pybind11::cpp_function::cpp_function(Func&&, const Extra& ...) [with Func = pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]::<lambda(const type&)>; Extra = {pybind11::is_method}; = void]’
/usr/local/include/pybind11/pybind11.h:1716:22: required from ‘pybind11::class_<type_, options>& pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]’
1.cpp:150:54: required from here
/usr/local/include/pybind11/cast.h:208:5: error: no type named ‘type’ in ‘struct std::enable_if<false, pybind11::handle>’
/usr/local/include/pybind11/pybind11.h: In instantiation of ‘void pybind11::cpp_function::initialize(Func&&, Return ()(Args ...), const Extra& ...) [with Func = pybind11::class_<type_, options>::def_readwrite(const char*, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]::<lambda(const type&)>; Return = const double (&)[3][3]; Args = {const Ctest&}; Extra = {pybind11::is_method}]’:
/usr/local/include/pybind11/pybind11.h:145:9: required from ‘pybind11::cpp_function::cpp_function(Func&&, const Extra& ...) [with Func = pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]::<lambda(const type&)>; Extra = {pybind11::is_method}; = void]’
/usr/local/include/pybind11/pybind11.h:1716:22: required from ‘pybind11::class_<type_, options>& pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]’
1.cpp:150:54: required from here
/usr/local/include/pybind11/cast.h:216:5: note: candidate: ‘template static typename std::enable_if<(((! std::is_floating_point::value) && std::is_signed::value) && (sizeof (U) <= sizeof (long int))), pybind11::handle>::type pybind11::detail::type_caster<T, typename std::enable_if<(std::is_arithmetic<_Tp>::value && (! pybind11::detail::negation<std::is_same<pybind11::detail::bools<pybind11::detail::negation<std::is_same<CharT, char> >::value, pybind11::detail::negation<std::is_same<CharT, char16_t> >::value, pybind11::detail::negation<std::is_same<CharT, char32_t> >::value, pybind11::detail::negation<std::is_same<CharT, wchar_t> >::value, true>, pybind11::detail::bools<true, pybind11::detail::negation<std::is_same<CharT, char> >::value, pybind11::detail::negation<std::is_same<CharT, char16_t> >::value, pybind11::detail::negation<std::is_same<CharT, char32_t> >::value, pybind11::detail::negation<std::is_same<CharT, wchar_t> >::value> > >::value)), void>::type>::cast(U, pybind11::return_value_policy, pybind11::handle) [with U = U; T = double]’
216 | cast(U src, return_value_policy / policy /, handle / parent /) {
| ^~~~
/usr/local/include/pybind11/cast.h:216:5: note: template argument deduction/substitution failed:
/usr/local/include/pybind11/cast.h: In substitution of ‘template static typename std::enable_if<(((! std::is_floating_point<_Tp>::value) && std::is_signed<_Tp>::value) && (sizeof (U) <= sizeof (long int))), pybind11::handle>::type pybind11::detail::type_caster<double, void>::cast(U, pybind11::return_value_policy, pybind11::handle) [with U = const double ()[3]]’:
/usr/local/include/pybind11/pybind11.h:296:40: required from ‘void pybind11::cpp_function::initialize(Func&&, Return ()(Args ...), const Extra& ...) [with Func = pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]::<lambda(const type&)>; Return = const double (&)[3][3]; Args = {const Ctest&}; Extra = {pybind11::is_method}]’
/usr/local/include/pybind11/pybind11.h:145:9: required from ‘pybind11::cpp_function::cpp_function(Func&&, const Extra& ...) [with Func = pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]::<lambda(const type&)>; Extra = {pybind11::is_method}; = void]’
/usr/local/include/pybind11/pybind11.h:1716:22: required from ‘pybind11::class_<type_, options>& pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]’
1.cpp:150:54: required from here
/usr/local/include/pybind11/cast.h:216:5: error: no type named ‘type’ in ‘struct std::enable_if<false, pybind11::handle>’
/usr/local/include/pybind11/pybind11.h: In instantiation of ‘void pybind11::cpp_function::initialize(Func&&, Return ()(Args ...), const Extra& ...) [with Func = pybind11::class_<type_, options>::def_readwrite(const char*, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]::<lambda(const type&)>; Return = const double (&)[3][3]; Args = {const Ctest&}; Extra = {pybind11::is_method}]’:
/usr/local/include/pybind11/pybind11.h:145:9: required from ‘pybind11::cpp_function::cpp_function(Func&&, const Extra& ...) [with Func = pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]::<lambda(const type&)>; Extra = {pybind11::is_method}; = void]’
/usr/local/include/pybind11/pybind11.h:1716:22: required from ‘pybind11::class_<type_, options>& pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]’
1.cpp:150:54: required from here
/usr/local/include/pybind11/cast.h:224:5: note: candidate: ‘template static typename std::enable_if<(((! std::is_floating_point::value) && std::is_unsigned::value) && (sizeof (U) <= sizeof (long unsigned int))), pybind11::handle>::type pybind11::detail::type_caster<T, typename std::enable_if<(std::is_arithmetic<_Tp>::value && (! pybind11::detail::negation<std::is_same<pybind11::detail::bools<pybind11::detail::negation<std::is_same<CharT, char> >::value, pybind11::detail::negation<std::is_same<CharT, char16_t> >::value, pybind11::detail::negation<std::is_same<CharT, char32_t> >::value, pybind11::detail::negation<std::is_same<CharT, wchar_t> >::value, true>, pybind11::detail::bools<true, pybind11::detail::negation<std::is_same<CharT, char> >::value, pybind11::detail::negation<std::is_same<CharT, char16_t> >::value, pybind11::detail::negation<std::is_same<CharT, char32_t> >::value, pybind11::detail::negation<std::is_same<CharT, wchar_t> >::value> > >::value)), void>::type>::cast(U, pybind11::return_value_policy, pybind11::handle) [with U = U; T = double]’
224 | cast(U src, return_value_policy / policy /, handle / parent /) {
| ^~~~
/usr/local/include/pybind11/cast.h:224:5: note: template argument deduction/substitution failed:
/usr/local/include/pybind11/cast.h: In substitution of ‘template static typename std::enable_if<(((! std::is_floating_point<_Tp>::value) && std::is_unsigned::value) && (sizeof (U) <= sizeof (long unsigned int))), pybind11::handle>::type pybind11::detail::type_caster<double, void>::cast(U, pybind11::return_value_policy, pybind11::handle) [with U = const double ()[3]]’:
/usr/local/include/pybind11/pybind11.h:296:40: required from ‘void pybind11::cpp_function::initialize(Func&&, Return ()(Args ...), const Extra& ...) [with Func = pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]::<lambda(const type&)>; Return = const double (&)[3][3]; Args = {const Ctest&}; Extra = {pybind11::is_method}]’
/usr/local/include/pybind11/pybind11.h:145:9: required from ‘pybind11::cpp_function::cpp_function(Func&&, const Extra& ...) [with Func = pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]::<lambda(const type&)>; Extra = {pybind11::is_method}; = void]’
/usr/local/include/pybind11/pybind11.h:1716:22: required from ‘pybind11::class_<type_, options>& pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]’
1.cpp:150:54: required from here
/usr/local/include/pybind11/cast.h:224:5: error: no type named ‘type’ in ‘struct std::enable_if<false, pybind11::handle>’
/usr/local/include/pybind11/pybind11.h: In instantiation of ‘void pybind11::cpp_function::initialize(Func&&, Return ()(Args ...), const Extra& ...) [with Func = pybind11::class_<type_, options>::def_readwrite(const char*, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]::<lambda(const type&)>; Return = const double (&)[3][3]; Args = {const Ctest&}; Extra = {pybind11::is_method}]’:
/usr/local/include/pybind11/pybind11.h:145:9: required from ‘pybind11::cpp_function::cpp_function(Func&&, const Extra& ...) [with Func = pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]::<lambda(const type&)>; Extra = {pybind11::is_method}; = void]’
/usr/local/include/pybind11/pybind11.h:1716:22: required from ‘pybind11::class_<type_, options>& pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]’
1.cpp:150:54: required from here
/usr/local/include/pybind11/cast.h:232:5: note: candidate: ‘template static typename std::enable_if<(((! std::is_floating_point::value) && std::is_signed::value) && (sizeof (U) > sizeof (long int))), pybind11::handle>::type pybind11::detail::type_caster<T, typename std::enable_if<(std::is_arithmetic<_Tp>::value && (! pybind11::detail::negation<std::is_same<pybind11::detail::bools<pybind11::detail::negation<std::is_same<CharT, char> >::value, pybind11::detail::negation<std::is_same<CharT, char16_t> >::value, pybind11::detail::negation<std::is_same<CharT, char32_t> >::value, pybind11::detail::negation<std::is_same<CharT, wchar_t> >::value, true>, pybind11::detail::bools<true, pybind11::detail::negation<std::is_same<CharT, char> >::value, pybind11::detail::negation<std::is_same<CharT, char16_t> >::value, pybind11::detail::negation<std::is_same<CharT, char32_t> >::value, pybind11::detail::negation<std::is_same<CharT, wchar_t> >::value> > >::value)), void>::type>::cast(U, pybind11::return_value_policy, pybind11::handle) [with U = U; T = double]’
232 | cast(U src, return_value_policy / policy /, handle / parent /) {
| ^~~~
/usr/local/include/pybind11/cast.h:232:5: note: template argument deduction/substitution failed:
/usr/local/include/pybind11/cast.h: In substitution of ‘template static typename std::enable_if<(((! std::is_floating_point<_Tp>::value) && std::is_signed<_Tp>::value) && (sizeof (U) > sizeof (long int))), pybind11::handle>::type pybind11::detail::type_caster<double, void>::cast(U, pybind11::return_value_policy, pybind11::handle) [with U = const double ()[3]]’:
/usr/local/include/pybind11/pybind11.h:296:40: required from ‘void pybind11::cpp_function::initialize(Func&&, Return ()(Args ...), const Extra& ...) [with Func = pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]::<lambda(const type&)>; Return = const double (&)[3][3]; Args = {const Ctest&}; Extra = {pybind11::is_method}]’
/usr/local/include/pybind11/pybind11.h:145:9: required from ‘pybind11::cpp_function::cpp_function(Func&&, const Extra& ...) [with Func = pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]::<lambda(const type&)>; Extra = {pybind11::is_method}; = void]’
/usr/local/include/pybind11/pybind11.h:1716:22: required from ‘pybind11::class_<type_, options>& pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]’
1.cpp:150:54: required from here
/usr/local/include/pybind11/cast.h:232:5: error: no type named ‘type’ in ‘struct std::enable_if<false, pybind11::handle>’
/usr/local/include/pybind11/pybind11.h: In instantiation of ‘void pybind11::cpp_function::initialize(Func&&, Return ()(Args ...), const Extra& ...) [with Func = pybind11::class_<type_, options>::def_readwrite(const char*, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]::<lambda(const type&)>; Return = const double (&)[3][3]; Args = {const Ctest&}; Extra = {pybind11::is_method}]’:
/usr/local/include/pybind11/pybind11.h:145:9: required from ‘pybind11::cpp_function::cpp_function(Func&&, const Extra& ...) [with Func = pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]::<lambda(const type&)>; Extra = {pybind11::is_method}; = void]’
/usr/local/include/pybind11/pybind11.h:1716:22: required from ‘pybind11::class_<type_, options>& pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]’
1.cpp:150:54: required from here
/usr/local/include/pybind11/cast.h:240:5: note: candidate: ‘template static typename std::enable_if<(((! std::is_floating_point::value) && std::is_unsigned::value) && (sizeof (U) > sizeof (long unsigned int))), pybind11::handle>::type pybind11::detail::type_caster<T, typename std::enable_if<(std::is_arithmetic<_Tp>::value && (! pybind11::detail::negation<std::is_same<pybind11::detail::bools<pybind11::detail::negation<std::is_same<CharT, char> >::value, pybind11::detail::negation<std::is_same<CharT, char16_t> >::value, pybind11::detail::negation<std::is_same<CharT, char32_t> >::value, pybind11::detail::negation<std::is_same<CharT, wchar_t> >::value, true>, pybind11::detail::bools<true, pybind11::detail::negation<std::is_same<CharT, char> >::value, pybind11::detail::negation<std::is_same<CharT, char16_t> >::value, pybind11::detail::negation<std::is_same<CharT, char32_t> >::value, pybind11::detail::negation<std::is_same<CharT, wchar_t> >::value> > >::value)), void>::type>::cast(U, pybind11::return_value_policy, pybind11::handle) [with U = U; T = double]’
240 | cast(U src, return_value_policy / policy /, handle / parent /) {
| ^~~~
/usr/local/include/pybind11/cast.h:240:5: note: template argument deduction/substitution failed:
/usr/local/include/pybind11/cast.h: In substitution of ‘template static typename std::enable_if<(((! std::is_floating_point<_Tp>::value) && std::is_unsigned::value) && (sizeof (U) > sizeof (long unsigned int))), pybind11::handle>::type pybind11::detail::type_caster<double, void>::cast(U, pybind11::return_value_policy, pybind11::handle) [with U = const double ()[3]]’:
/usr/local/include/pybind11/pybind11.h:296:40: required from ‘void pybind11::cpp_function::initialize(Func&&, Return ()(Args ...), const Extra& ...) [with Func = pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]::<lambda(const type&)>; Return = const double (&)[3][3]; Args = {const Ctest&}; Extra = {pybind11::is_method}]’
/usr/local/include/pybind11/pybind11.h:145:9: required from ‘pybind11::cpp_function::cpp_function(Func&&, const Extra& ...) [with Func = pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]::<lambda(const type&)>; Extra = {pybind11::is_method}; = void]’
/usr/local/include/pybind11/pybind11.h:1716:22: required from ‘pybind11::class_<type_, options>& pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]’
1.cpp:150:54: required from here
/usr/local/include/pybind11/cast.h:240:5: error: no type named ‘type’ in ‘struct std::enable_if<false, pybind11::handle>’
/usr/local/include/pybind11/pybind11.h: In instantiation of ‘void pybind11::cpp_function::initialize(Func&&, Return ()(Args ...), const Extra& ...) [with Func = pybind11::class_<type_, options>::def_readwrite(const char*, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]::<lambda(const type&)>; Return = const double (&)[3][3]; Args = {const Ctest&}; Extra = {pybind11::is_method}]’:
/usr/local/include/pybind11/pybind11.h:145:9: required from ‘pybind11::cpp_function::cpp_function(Func&&, const Extra& ...) [with Func = pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]::<lambda(const type&)>; Extra = {pybind11::is_method}; = void]’
/usr/local/include/pybind11/pybind11.h:1716:22: required from ‘pybind11::class_<type_, options>& pybind11::class_<type_, options>::def_readwrite(const char, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]’
1.cpp:150:54: required from here
/usr/local/include/pybind11/cast.h:244:5: note: candidate: ‘template<class T_, typename std::enable_if<std::is_same<double, typename std::remove_cv< >::type>::value, int>::type > static pybind11::handle pybind11::detail::type_caster<T, typename std::enable_if<(std::is_arithmetic<Tp>::value && (! pybind11::detail::negation<std::is_same<pybind11::detail::bools<pybind11::detail::negation<std::is_same<CharT, char> >::value, pybind11::detail::negation<std::is_same<CharT, char16_t> >::value, pybind11::detail::negation<std::is_same<CharT, char32_t> >::value, pybind11::detail::negation<std::is_same<CharT, wchar_t> >::value, true>, pybind11::detail::bools<true, pybind11::detail::negation<std::is_same<CharT, char> >::value, pybind11::detail::negation<std::is_same<CharT, char16_t> >::value, pybind11::detail::negation<std::is_same<CharT, char32_t> >::value, pybind11::detail::negation<std::is_same<CharT, wchar_t> >::value> > >::value)), void>::type>::cast(T, pybind11::return_value_policy, pybind11::handle) [with T_ = T_; typename std::enable_if<std::is_same<T, typename std::remove_cv<Up>::type>::value, int>::type = ; T = double]’
244 | PYBIND11_TYPE_CASTER(T, const_name<std::is_integral::value>("int", "float"));
| ^~~~~~~~~~~~~~~~~~~~
/usr/local/include/pybind11/cast.h:244:5: note: template argument deduction/substitution failed:
/usr/local/include/pybind11/cast.h:244:5: error: no type named ‘type’ in ‘struct std::enable_if<false, int>’
244 | PYBIND11_TYPE_CASTER(T, const_name<std::is_integral::value>("int", "float"));
| ^~~~~~~~~~~~~~~~~~~~
In file included from /usr/local/include/pybind11/embed.h:12,
from 1.cpp:1:
/usr/local/include/pybind11/pybind11.h:144:5: error: ‘pybind11::cpp_function::cpp_function(Func&&, const Extra& ...) [with Func = pybind11::class<type_, options>::def_readwrite(const char*, D C::, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]::<lambda(pybind11::class_::type&, const double (&)[3][3])>; Extra = {pybind11::is_method}; = void]’, declared using local type ‘pybind11::class_<type_, options>::def_readwrite(const char, D C::*, const Extra& ...) [with C = Ctest; D = double [3][3]; Extra = {}; type_ = Ctest; options = {}]::<lambda(pybind11::class_::type&, const double (&)[3][3])>’, is used but never defined [-fpermissive]
144 | cpp_function(Func &&f, const Extra &...extra) {
| ^~~~~~~~~~~~

[huqin-RM]

class Ctest
{
public:
int m_vdMat[3][3] = {{1,2,3},{4,2,3},{1,8,3}};
};

PYBIND11_EMBEDDED_MODULE(fast_calc,m){

py::class_<Ctest>(m, "Ctest")
        .def(py::init<>())
        .def("m_vdMat", [](Ctest &s){
                                         py::object sb = py::cast(s);
                                         pybind11::buffer_info info = pybind11::buffer_info(s.m_vdMat, sizeof(int), pybind11::format_descriptor<int>::format(), 2, {3,3}, {sizeof(int)*3, sizeof(int)});
                                         pybind11::array arr(info, sb.ptr());
                                         return  arr;
                                       });

[evguran]

Hi, attributes indeed defined via def_readwrite, but why do you refer to CIntrinsicsM class?
.def_readwrite("m_vdMat", &CIntrinsicsM::m_vdMat);
I suppose you should also #include "pybind11/stl.h"