/usr/include/qt5/QtCore/qjsonvalue.h:163:19: note:   candidate expects 0 arguments, 1 provided
project/Project_loading.cpp:1224:81: error: no matching function for call to ‘QJsonValueRef::toDouble(double)’
             std::get<2>(i.layering_normal)=layering_normal_array[2].toDouble(1.0);
                                                                                 ^
project/Project_loading.cpp:1224:81: note: candidate is:
In file included from /usr/include/qt5/QtCore/qjsondocument.h:45:0,
                 from /usr/include/qt5/QtCore/QJsonDocument:1,
                 from project/Project.h:10,
                 from project/Project_loading.cpp:1:
/usr/include/qt5/QtCore/qjsonvalue.h:163:19: note: double QJsonValueRef::toDouble() const
     inline double toDouble() const { return toValue().toDouble(); }
                   ^
/usr/include/qt5/QtCore/qjsonvalue.h:163:19: note:   candidate expects 0 arguments, 1 provided
make: *** [Project_loading.o] Error 1