Comments (6)
grisumbras
commented on May 30, 2024
1
That will most likely happen in the next release, because another feature would benefit from it.
from json.
grisumbras
commented on May 30, 2024
Seems to work for me: https://godbolt.org/z/bY1x1fhff
So, I need more information than what you have provided. Ideally a Minimal Reproducible Example.
from json.
tobias-loew
commented on May 30, 2024
I had a closer look: The structure of my code is slightly more complicated.
#include <variant>
#include <boost/json/value_to.hpp>
template< class T > struct some_base_type {
};
template<typename T>
using some_type = std::variant<some_base_type<T>, int, char const*>;
template< class T >
some_type<T>
tag_invoke(
boost::json::value_to_tag< some_type<T> > const&,
boost::json::value const& jv)
{
boost::json::string const* str = jv.if_string();
if (str && *str == "T11")
return some_type<T>{""};
throw std::invalid_argument("!");
}
some_type<int> foo(boost::json::value jv)
{
return boost::json::value_to< some_type<int> >(jv);
}
I use VS 2022 with MSVC 143 /std:c++latest
This compiles with 1.81 (see https://godbolt.org/z/TjvfYsaTb vcpkg is still on 1,81) but fails with >= 1.82.
Here is my error log:
Build started...
1>------ Build started: Project: ConsoleApplication3, Configuration: Debug x64 ------
1>ConsoleApplication3.cpp
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(230,20): error C2672: 'value_to_impl': no matching overloaded function found
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(813,1): message : could be 'T boost::json::detail::value_to_impl(Impl,boost::json::value_to_tag<T>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(230,20): message : 'T boost::json::detail::value_to_impl(Impl,boost::json::value_to_tag<T>,const boost::json::value &,const Ctx &)': could not deduce template argument for 'boost::json::value_to_tag<T>' from 'boost::json::try_value_to_tag<T>'
1> with
1> [
1> T=bare_T
1> ]
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(803,1): message : or 'T boost::json::detail::value_to_impl(boost::json::detail::no_conversion_tag,boost::json::value_to_tag<T>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(230,20): message : 'T boost::json::detail::value_to_impl(boost::json::detail::no_conversion_tag,boost::json::value_to_tag<T>,const boost::json::value &,const Ctx &)': could not deduce template argument for 'boost::json::value_to_tag<T>' from 'boost::json::try_value_to_tag<T>'
1> with
1> [
1> T=bare_T
1> ]
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(786,1): message : or 'detail::mp_if_c_impl<!boost::mp11::mp_valid<boost::json::detail::has_nonthrowing_full_context_conversion_to_impl,Sup::type,T>::value,boost::system::result<T,boost::system::error_code>,>::type boost::json::detail::value_to_impl(boost::json::detail::full_context_conversion_tag,boost::json::try_value_to_tag<T>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : 'initializing': cannot convert from 'cat' to 'boost::json::detail::full_context_conversion_tag'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(765,1): message : or 'detail::mp_if_c_impl<!boost::mp11::mp_valid<boost::json::detail::has_nonthrowing_context_conversion_to_impl,Sup::type,T>::value,boost::system::result<T,boost::system::error_code>,>::type boost::json::detail::value_to_impl(boost::json::detail::context_conversion_tag,boost::json::try_value_to_tag<T>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : 'initializing': cannot convert from 'cat' to 'boost::json::detail::context_conversion_tag'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(747,1): message : or 'detail::mp_if_c_impl<!boost::mp11::mp_valid<boost::json::detail::has_nonthrowing_user_conversion_to_impl,T>::value,boost::system::result<T,boost::system::error_code>,>::type boost::json::detail::value_to_impl(boost::json::detail::user_conversion_tag,boost::json::try_value_to_tag<T>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : 'initializing': cannot convert from 'cat' to 'boost::json::detail::user_conversion_tag'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(682,1): message : or 'detail::mp_if_c_impl<boost::mp11::detail::mp_valid_impl<boost::json::detail::has_nonthrowing_full_context_conversion_to_impl,Sup::type,T>::type::value,boost::system::result<T,boost::system::error_code>,>::type boost::json::detail::value_to_impl(boost::json::detail::full_context_conversion_tag,boost::json::try_value_to_tag<T>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : 'initializing': cannot convert from 'cat' to 'boost::json::detail::full_context_conversion_tag'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(662,1): message : or 'detail::mp_if_c_impl<boost::mp11::detail::mp_valid_impl<boost::json::detail::has_nonthrowing_context_conversion_to_impl,Sup::type,T>::type::value,boost::system::result<T,boost::system::error_code>,>::type boost::json::detail::value_to_impl(boost::json::detail::context_conversion_tag,boost::json::try_value_to_tag<T>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : 'initializing': cannot convert from 'cat' to 'boost::json::detail::context_conversion_tag'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(647,1): message : or 'detail::mp_if_c_impl<boost::mp11::detail::mp_valid_impl<boost::json::detail::has_nonthrowing_user_conversion_to_impl,T>::type::value,boost::system::result<T,boost::system::error_code>,>::type boost::json::detail::value_to_impl(boost::json::detail::user_conversion_tag,boost::json::try_value_to_tag<T>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : 'initializing': cannot convert from 'cat' to 'boost::json::detail::user_conversion_tag'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(626,1): message : or 'detail::mp_if_c_impl<!boost::mp11::mp_valid<boost::json::detail::has_full_context_conversion_to_impl,Sup::type,T>::value,T,>::type boost::json::detail::value_to_impl(boost::json::detail::full_context_conversion_tag,boost::json::value_to_tag<T>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(230,20): message : 'detail::mp_if_c_impl<!boost::mp11::mp_valid<boost::json::detail::has_full_context_conversion_to_impl,Sup::type,T>::value,T,>::type boost::json::detail::value_to_impl(boost::json::detail::full_context_conversion_tag,boost::json::value_to_tag<T>,const boost::json::value &,const Ctx &)': could not deduce template argument for 'boost::json::value_to_tag<T>' from 'boost::json::try_value_to_tag<T>'
1> with
1> [
1> T=bare_T
1> ]
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(586,1): message : or 'detail::mp_if_c_impl<!boost::mp11::mp_valid<boost::json::detail::has_context_conversion_to_impl,Sup::type,T>::value,T,>::type boost::json::detail::value_to_impl(boost::json::detail::context_conversion_tag,boost::json::value_to_tag<T>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(230,20): message : 'detail::mp_if_c_impl<!boost::mp11::mp_valid<boost::json::detail::has_context_conversion_to_impl,Sup::type,T>::value,T,>::type boost::json::detail::value_to_impl(boost::json::detail::context_conversion_tag,boost::json::value_to_tag<T>,const boost::json::value &,const Ctx &)': could not deduce template argument for 'boost::json::value_to_tag<T>' from 'boost::json::try_value_to_tag<T>'
1> with
1> [
1> T=bare_T
1> ]
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(568,1): message : or 'detail::mp_if_c_impl<!boost::mp11::mp_valid<boost::json::detail::has_user_conversion_to_impl,T>::value,T,>::type boost::json::detail::value_to_impl(boost::json::detail::user_conversion_tag,boost::json::value_to_tag<T>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(230,20): message : 'detail::mp_if_c_impl<!boost::mp11::mp_valid<boost::json::detail::has_user_conversion_to_impl,T>::value,T,>::type boost::json::detail::value_to_impl(boost::json::detail::user_conversion_tag,boost::json::value_to_tag<T>,const boost::json::value &,const Ctx &)': could not deduce template argument for 'boost::json::value_to_tag<T>' from 'boost::json::try_value_to_tag<T>'
1> with
1> [
1> T=bare_T
1> ]
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(555,1): message : or 'detail::mp_if_c_impl<boost::mp11::detail::mp_valid_impl<boost::json::detail::has_full_context_conversion_to_impl,Sup::type,T>::type::value,T,>::type boost::json::detail::value_to_impl(boost::json::detail::full_context_conversion_tag,boost::json::value_to_tag<T>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(230,20): message : 'detail::mp_if_c_impl<boost::mp11::detail::mp_valid_impl<boost::json::detail::has_full_context_conversion_to_impl,Sup::type,T>::type::value,T,>::type boost::json::detail::value_to_impl(boost::json::detail::full_context_conversion_tag,boost::json::value_to_tag<T>,const boost::json::value &,const Ctx &)': could not deduce template argument for 'boost::json::value_to_tag<T>' from 'boost::json::try_value_to_tag<T>'
1> with
1> [
1> T=bare_T
1> ]
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(537,1): message : or 'detail::mp_if_c_impl<boost::mp11::detail::mp_valid_impl<boost::json::detail::has_context_conversion_to_impl,Sup::type,T>::type::value,T,>::type boost::json::detail::value_to_impl(boost::json::detail::context_conversion_tag,boost::json::value_to_tag<T>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(230,20): message : 'detail::mp_if_c_impl<boost::mp11::detail::mp_valid_impl<boost::json::detail::has_context_conversion_to_impl,Sup::type,T>::type::value,T,>::type boost::json::detail::value_to_impl(boost::json::detail::context_conversion_tag,boost::json::value_to_tag<T>,const boost::json::value &,const Ctx &)': could not deduce template argument for 'boost::json::value_to_tag<T>' from 'boost::json::try_value_to_tag<T>'
1> with
1> [
1> T=bare_T
1> ]
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(524,1): message : or 'detail::mp_if_c_impl<boost::mp11::detail::mp_valid_impl<boost::json::detail::has_user_conversion_to_impl,T>::type::value,T,>::type boost::json::detail::value_to_impl(boost::json::detail::user_conversion_tag,boost::json::value_to_tag<T>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(230,20): message : 'detail::mp_if_c_impl<boost::mp11::detail::mp_valid_impl<boost::json::detail::has_user_conversion_to_impl,T>::type::value,T,>::type boost::json::detail::value_to_impl(boost::json::detail::user_conversion_tag,boost::json::value_to_tag<T>,const boost::json::value &,const Ctx &)': could not deduce template argument for 'boost::json::value_to_tag<T>' from 'boost::json::try_value_to_tag<T>'
1> with
1> [
1> T=bare_T
1> ]
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(492,1): message : or 'boost::system::result<T,boost::system::error_code> boost::json::detail::value_to_impl(boost::json::detail::described_enum_conversion_tag,boost::json::try_value_to_tag<T>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : 'initializing': cannot convert from 'cat' to 'boost::json::detail::described_enum_conversion_tag'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(452,1): message : or 'boost::system::result<T,boost::system::error_code> boost::json::detail::value_to_impl(boost::json::detail::described_class_conversion_tag,boost::json::try_value_to_tag<T>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : 'initializing': cannot convert from 'cat' to 'boost::json::detail::described_class_conversion_tag'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(353,1): message : or 'boost::system::result<T,boost::system::error_code> boost::json::detail::value_to_impl(boost::json::detail::tuple_conversion_tag,boost::json::try_value_to_tag<T>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : 'initializing': cannot convert from 'cat' to 'boost::json::detail::tuple_conversion_tag'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(285,1): message : or 'boost::system::result<T,boost::system::error_code> boost::json::detail::value_to_impl(boost::json::detail::sequence_conversion_tag,boost::json::try_value_to_tag<T>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : 'initializing': cannot convert from 'cat' to 'boost::json::detail::sequence_conversion_tag'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(245,1): message : or 'boost::system::result<T,boost::system::error_code> boost::json::detail::value_to_impl(boost::json::detail::map_like_conversion_tag,boost::json::try_value_to_tag<T>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : 'initializing': cannot convert from 'cat' to 'boost::json::detail::map_like_conversion_tag'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(228,1): message : or 'boost::system::result<T,boost::system::error_code> boost::json::detail::value_to_impl(boost::json::detail::string_like_conversion_tag,boost::json::try_value_to_tag<T>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : 'initializing': cannot convert from 'cat' to 'boost::json::detail::string_like_conversion_tag'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(212,1): message : or 'boost::system::result<T,boost::system::error_code> boost::json::detail::value_to_impl(boost::json::detail::null_like_conversion_tag,boost::json::try_value_to_tag<T>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : 'initializing': cannot convert from 'cat' to 'boost::json::detail::null_like_conversion_tag'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(199,1): message : or 'boost::system::result<T,boost::system::error_code> boost::json::detail::value_to_impl(boost::json::detail::number_conversion_tag,boost::json::try_value_to_tag<T>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : 'initializing': cannot convert from 'cat' to 'boost::json::detail::number_conversion_tag'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(185,1): message : or 'boost::system::result<bool,boost::system::error_code> boost::json::detail::value_to_impl(boost::json::detail::bool_conversion_tag,boost::json::try_value_to_tag<bool>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : 'initializing': cannot convert from 'cat' to 'boost::json::detail::bool_conversion_tag'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(168,1): message : or 'boost::system::result<boost::json::string,boost::system::error_code> boost::json::detail::value_to_impl(boost::json::detail::string_conversion_tag,boost::json::try_value_to_tag<boost::json::string>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : 'initializing': cannot convert from 'cat' to 'boost::json::detail::string_conversion_tag'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(151,1): message : or 'boost::system::result<boost::json::array,boost::system::error_code> boost::json::detail::value_to_impl(boost::json::detail::array_conversion_tag,boost::json::try_value_to_tag<boost::json::array>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : 'initializing': cannot convert from 'cat' to 'boost::json::detail::array_conversion_tag'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(134,1): message : or 'boost::system::result<boost::json::object,boost::system::error_code> boost::json::detail::value_to_impl(boost::json::detail::object_conversion_tag,boost::json::try_value_to_tag<boost::json::object>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : 'initializing': cannot convert from 'cat' to 'boost::json::detail::object_conversion_tag'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(125,1): message : or 'boost::json::value boost::json::detail::value_to_impl(boost::json::detail::value_conversion_tag,boost::json::value_to_tag<boost::json::value>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : 'initializing': cannot convert from 'cat' to 'boost::json::detail::value_conversion_tag'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(114,1): message : or 'boost::system::result<boost::json::value,boost::system::error_code> boost::json::detail::value_to_impl(boost::json::detail::value_conversion_tag,boost::json::try_value_to_tag<boost::json::value>,const boost::json::value &,const Ctx &)'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : 'initializing': cannot convert from 'cat' to 'boost::json::detail::value_conversion_tag'
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(231,12): message : No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(875,24): message : see reference to function template instantiation 'boost::system::result<some_base_type<int>,boost::system::error_code> boost::json::try_value_to<T,Ctx2>(const boost::json::value &,const Context &)' being compiled
1> with
1> [
1> Ctx2=std::tuple<boost::json::detail::allow_exceptions,boost::json::detail::no_context>,
1> Context=std::tuple<boost::json::detail::allow_exceptions,boost::json::detail::no_context>
1> ]
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\mp11\algorithm.hpp(1060,28): message : see reference to function template instantiation 'void boost::json::tag_invoke::<lambda_1>::operator ()<std::integral_constant<size_t,0>>(_T1) const' being compiled
1> with
1> [
1> _T1=std::integral_constant<size_t,0>
1> ]
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\mp11\algorithm.hpp(1076,20): message : see reference to function template instantiation 'F boost::mp11::detail::mp_for_each_impl<std::integral_constant<size_t,0>,std::integral_constant<unsigned __int64,1>,std::integral_constant<size_t,2>,_Ty>(boost::mp11::mp_list<std::integral_constant<size_t,0>,std::integral_constant<unsigned __int64,1>,std::integral_constant<size_t,2>>,F &&)' being compiled
1> with
1> [
1> F=boost::json::tag_invoke::<lambda_1>,
1> _Ty=boost::json::tag_invoke::<lambda_1>
1> ]
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(870,11): message : see reference to function template instantiation 'boost::json::tag_invoke::<lambda_1> boost::mp11::mp_for_each<boost::mp11::mp_list<std::integral_constant<size_t,0>,std::integral_constant<unsigned __int64,1>,std::integral_constant<size_t,2>>,boost::json::tag_invoke::<lambda_1>>(F &&)' being compiled
1> with
1> [
1> F=boost::json::tag_invoke::<lambda_1>
1> ]
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\detail\value_to.hpp(632,16): message : see reference to function template instantiation 'boost::system::result<std::variant<some_base_type<int>,int,const char *>,boost::system::error_code> boost::json::tag_invoke<some_base_type<int>,int,const char*,boost::json::detail::no_context,std::tuple<boost::json::detail::allow_exceptions,Ctx>>(boost::json::try_value_to_tag<T>,const boost::json::value &,const Ctx1 &,const Ctx2 &)' being compiled
1> with
1> [
1> Ctx=boost::json::detail::no_context,
1> T=bare_T,
1> Ctx1=boost::json::detail::no_context,
1> Ctx2=std::tuple<boost::json::detail::allow_exceptions,boost::json::detail::no_context>
1> ]
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(96,20): message : see reference to function template instantiation 'std::variant<some_base_type<int>,int,const char *> boost::json::detail::value_to_impl<T,Context,boost::json::detail::supported_context<Ctx,T,boost::json::detail::value_to_conversion>>(boost::json::detail::full_context_conversion_tag,boost::json::value_to_tag<T>,const boost::json::value &,const Ctx &)' being compiled
1> with
1> [
1> T=bare_T,
1> Context=boost::json::detail::no_context,
1> Ctx=boost::json::detail::no_context
1> ]
1>D:\loew\proj\ebsilon.git\build\SRC\Libs\boost\AnyCPU\boost\boost\json\value_to.hpp(148,12): message : see reference to function template instantiation 'T boost::json::value_to<std::variant<some_base_type<int>,int,const char *>,boost::json::detail::no_context>(const boost::json::value &,const Context &)' being compiled
1> with
1> [
1> T=std::variant<some_base_type<int>,int,const char *>,
1> Context=boost::json::detail::no_context
1> ]
1>C:\Users\K8705963\source\repos\ConsoleApplication3\ConsoleApplication3\ConsoleApplication3.cpp(27,25): message : see reference to function template instantiation 'T boost::json::value_to<std::variant<some_base_type<int>,int,const char *>>(const boost::json::value &)' being compiled
1> with
1> [
1> T=std::variant<some_base_type<int>,int,const char *>
1> ]
1>Done building project "ConsoleApplication3.vcxproj" -- FAILED.
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
========== Build started at 10:42 AM and took 02.027 seconds ==========
from json.
grisumbras
commented on May 30, 2024
Ok, I did pinpoint your problem. It affects 1.83.0 and not 1.82.0.
from json.
grisumbras
commented on May 30, 2024
OK, so the source of your problem is that the library provides a higher ranked conversion for std::variant now. This is due to a new feature called "contextual conversions". In order to get your conversion to rank better you have to add extra parameters:
template< class T, class Ctx1, class Ctx2 >
some_type<T>
tag_invoke(
boost::json::value_to_tag< some_type<T> > const&,
boost::json::value const& jv,
Ctx1 const&,
Ctx2 const& ctx)
{
// use value_to< X >( jv, ctx );
(void) ctx;
boost::json::string const* str = jv.if_string();
if (str && *str == "T11")
return some_type<T>{""};
throw std::invalid_argument("!");
}If you're interested what these parameters do, first context parameter is needed to provide "special" conversions. Here it isn't needed. Second context parameter is the full context given by the caller. Composite types (like vector or variant) need to marshall it to conversions of elements.
Just to be clear, if you don't need contexts in your program, you can ignore them. But the parameters (and template parameters) have to be present, so that your overload ranks high enough.
from json.
tobias-loew
commented on May 30, 2024
Thanks a lot for the clarification and sorry for messing up the version numbers.
I also had to fix my tag_invokes for value_from.
Now everything works again.
As an afterthough: With the new variant-support it would have been better to create a concept for the types in the variant, and then overload tag_invoke on that concept.
from json.
Related Issues (20)
- Can the value_from function add iterator parameters, such as value_from (Iterator begin, Iterator end) HOT 5
- boost::json::value_to on std::bitset? HOT 6
- Regression: serializing vector<> of objects HOT 4
- Linux gcc compilation failures with --pedantic-errors flag: error: extra ‘;’ HOT 1
- Value Iteration HOT 5
- Question: how to determine the required size for temp buffers? HOT 7
- If an unsigned integer is serialized, deserializing back to the unsigned integer fails HOT 8
- Comment Only: Logo HOT 3
- Stack exaustion while value_from(std::filesystem::path) HOT 5
- Small help for non eagle eyed people HOT 2
- Documentation inconsistency about exceptions HOT 2
- Add a convenience member function to call value_to HOT 5
- boost::json::value::is_uint64() behaves unintuitively HOT 6
- Add support to universal tag_invoke for class as struct with macro BOOST_DESCRIBE_CLASS HOT 10
- Unable to extract boolean value in numberic format HOT 1
- Add a shorthand to masquerade a type parsing/serializing HOT 1
- Allow unknown described class members with a parse option HOT 5
- Null-dereference warning in value_to HOT 2
- Error in parse_into() Error: unknown name or Error: incomplete JSON HOT 2
- Backwards compatibility? (new structure definitions but old json serialization) HOT 17
Recommend Projects
-
React
A declarative, efficient, and flexible JavaScript library for building user interfaces.
-
Vue.js
🖖 Vue.js is a progressive, incrementally-adoptable JavaScript framework for building UI on the web.
-
Typescript
TypeScript is a superset of JavaScript that compiles to clean JavaScript output.
-
TensorFlow
An Open Source Machine Learning Framework for Everyone
-
Django
The Web framework for perfectionists with deadlines.
-
Laravel
A PHP framework for web artisans
-
D3
Bring data to life with SVG, Canvas and HTML. 📊📈🎉
-
Recommend Topics
-
javascript
JavaScript (JS) is a lightweight interpreted programming language with first-class functions.
-
web
Some thing interesting about web. New door for the world.
-
server
A server is a program made to process requests and deliver data to clients.
-
Machine learning
Machine learning is a way of modeling and interpreting data that allows a piece of software to respond intelligently.
-
Visualization
Some thing interesting about visualization, use data art
-
Game
Some thing interesting about game, make everyone happy.
Recommend Org
-
Facebook
We are working to build community through open source technology. NB: members must have two-factor auth.
-
Microsoft
Open source projects and samples from Microsoft.
-
Google
Google ❤️ Open Source for everyone.
-
Alibaba
Alibaba Open Source for everyone
-
D3
Data-Driven Documents codes.
-
Tencent
China tencent open source team.
from json.