Hi all - I have a struct which holds parameter name/value pairs. The incoming data is not always exactly the same, as it's read from different sources, so sometimes I might have a parameter named "scale" which is a uint8_t, and other times "scale" is a uint32_t or int32_t. When I try to get() the data, I grab it as uint32_t, but it may be stored in the variant as an int32_t. We're using get<uint32_t> in that case, and this fails if the variant holds int32_t. On the other hand, since the variant can contain vector and matrix values, we can't simply use operator = for automatic casting (compile time errors). We don't expect to do any non-trivial casts (i.e. matrix to float or vice-versa). Are there any helper visitors or anything in the boost::variant library to assist with this, or do we need to write our own visitor? Code below. Thanks, Brian struct ParameterDesc { typedef boost::variant<bool, int32_t, uint32_t, float, Vec2f, Vec3f, Vec4f, Mat2f, Mat3f, Mat4f, std::string> ParamValue; typedef google::dense_hash_map<std::string, ParamValue> ParamMap; typedef ParamMap::iterator ParamMapIter; typedef ParamMap::const_iterator ParamMapCIter; std::string type; std::string name; ParamMap params; template <typename T> bool get(const std::string &name, T &val, const T &defaultValue) const { ParamMapCIter p_it; if( (p_it = params.find(name)) == params.end() ) { val = defaultValue; return false; } val = boost::get<T>(p_it->second); return true; } template <typename T> void get(const std::string &name, T &val) const { ParamMapCIter p_it; if( (p_it = params.find(name)) == params.end() ) { throw ParamException("couldn't find parameter with field name: " + name); } val = boost::get<T>(p_it->second); } ParameterDesc() { params.set_empty_key("__EMPTY__"); } };