How to make a vectors unmodifiable when passing?

My wording might not be correct, but I hope you’ll understand what I mean.

Basically I have a map<enum class, vector<struct*>>. I want to pass the whole map without the vectors’ contents being modifiable.
I need the structs as pointers, because I save references to some of them e.g. to the player instance and they’ll get invalidated otherwhise.

It seems I can neither pass the map nor the vectors by reference. So this..

    std::map<myEnum, std::vector<const myStruct&>> getMap() {
        return myMap;
    }

..aswell as..

    const std::map<myEnum, std::vector<myStruct*>>& getMap() {
        return myMap;
    }

doesnt work.

Is there any way to solve this?

Sorry if the question is dumb, I’m kinda new to C++ and often don’t know what to search for.
Thanks for you help!

>Solution :

First of all, you should declare the member function itself const, otherwise it can’t pick the member function for the const circumstance when the object itself is const.

Second, you don’t have to think about the exact typing, you can let the compiler figure it out by saying const auto&. then it will return a constant reference, so it won’t be modifiable:

const auto& GameLogic::getMap() const {
    return myMap;
}