1>------ Build started: Project: nlohmann_json_test, Configuration: Debug x64 ------ 1>nlohmannjsontest.cpp 1>c:\[developer-work]\nlohmann_json_test\json\src\json.hpp(1306): error C2338: could not find to_json() method in T's namespace 1>c:\[developer-work]\nlohmann_json_test\json\src\json.hpp(1314): note: see reference to function template instantiation 'void nlohmann::detail::to_json_fn::call,std::allocator>&>(BasicJsonType &,T,nlohmann::detail::priority_tag<0>) noexcept const' being compiled 1> with 1> [ 1> BasicJsonType=nlohmann::basic_json, 1> T=std::basic_string,std::allocator> & 1> ] 1>c:\[developer-work]\nlohmann_json_test\json\src\json.hpp(6918): note: see reference to function template instantiation 'void nlohmann::detail::to_json_fn::operator (),std::allocator>&>(BasicJsonType &,T) noexcept const' being compiled 1> with 1> [ 1> BasicJsonType=nlohmann::basic_json, 1> T=std::basic_string,std::allocator> & 1> ] 1>c:\[developer-work]\nlohmann_json_test\json\src\json.hpp(8396): note: see reference to function template instantiation 'void nlohmann::adl_serializer::to_json,std::allocator>&>(BasicJsonType &,ValueType) noexcept' being compiled 1> with 1> [ 1> T=std::basic_string,std::allocator>, 1> BasicJsonType=nlohmann::basic_json, 1> ValueType=std::basic_string,std::allocator> & 1> ] 1>c:\[developer-work]\nlohmann_json_test\json\src\json.hpp(8396): note: see reference to function template instantiation 'void nlohmann::adl_serializer::to_json,std::allocator>&>(BasicJsonType &,ValueType) noexcept' being compiled 1> with 1> [ 1> T=std::basic_string,std::allocator>, 1> BasicJsonType=nlohmann::basic_json, 1> ValueType=std::basic_string,std::allocator> & 1> ] 1>c:\[developer-work]\nlohmann_json_test\json\src\json.hpp(3057): note: see reference to function template instantiation 'nlohmann::basic_json::basic_json,std::allocator>&,std::basic_string,std::allocator>,0>(CompatibleType) noexcept' being compiled 1> with 1> [ 1> CompatibleType=std::basic_string,std::allocator> & 1> ] 1>c:\[developer-work]\nlohmann_json_test\json\src\json.hpp(3057): note: see reference to function template instantiation 'nlohmann::basic_json::basic_json,std::allocator>&,std::basic_string,std::allocator>,0>(CompatibleType) noexcept' being compiled 1> with 1> [ 1> CompatibleType=std::basic_string,std::allocator> & 1> ] 1>c:\[developer-work]\nlohmann_json_test\json\src\json.hpp(3004): note: while compiling class template member function 'void nlohmann::detail::parser>::parse_internal(bool,BasicJsonType &)' 1> with 1> [ 1> BasicJsonType=nlohmann::basic_json 1> ] 1>c:\[developer-work]\nlohmann_json_test\json\src\json.hpp(2951): note: see reference to function template instantiation 'void nlohmann::detail::parser>::parse_internal(bool,BasicJsonType &)' being compiled 1> with 1> [ 1> BasicJsonType=nlohmann::basic_json 1> ] 1>c:\[developer-work]\nlohmann_json_test\json\src\json.hpp(8213): note: see reference to class template instantiation 'nlohmann::detail::parser>' being compiled 1>c:\program files (x86)\microsoft visual studio\2017\community\vc\tools\msvc\14.11.25503\include\type_traits(867): note: see reference to class template instantiation 'nlohmann::basic_json' being compiled 1>c:\program files (x86)\microsoft visual studio\2017\community\vc\tools\msvc\14.11.25503\include\type_traits(901): note: see reference to class template instantiation 'std::is_nothrow_constructible<_Ty,_Ty>' being compiled 1> with 1> [ 1> _Ty=nlohmann::json 1> ] 1>c:\[developer-work]\nlohmann_json_test\json\src\json.hpp(14551): note: see reference to class template instantiation 'std::is_nothrow_move_constructible' being compiled 1>Done building project "nlohmann_json_test.vcxproj" -- FAILED. ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========