Question

I’m getting the following error when trying to build:

error: invalid initialization of non-const reference of type "std::vector<......"

Code:

class Config {
    public:
        std::vector<string>& GetValuesForList(std::string listName);

    private:
        std::map<std::string, std::vector<string> > lists;
    };

    inline std::vector<string>&
    Config::GetValuesForList(std::string listName) {
        return lists.find(listName);
    }

I’ve read up on it and seems to be because of C++ temporaries, but am unsure how to resolve it. Any help would be greatly appreciated.

Thanks.

Answer 1

map::find returns iterator. So you should use it’s second value:

    inline std::vector<string>&
    Config::GetValuesForList(std::string listName) {
        return lists.find(listName)->second;
    }