Problems with Menu?

[blackpill0w]

Hi,

I am trying create a Menu but the items I have are not std::string, I have, a list of struct A and I want a field of the struct (which is a string) in the menu, do I need to keep a copy of them in an std::vector<std::string> for the Menu?
I can't even use a vector of char * or std::string_view which would be way better.
Or maybe we could add something like this

Component Menu(std::vector<T> entries, /* other stuff */, std::function<std::string(T&)> convertEntriesToString);

to convert entries to string each time you render,

thanks.

[ArthurSonzogni]

This might be a bit costly to call the functor everytime we need to observe the list size.

I was thinking adding an option to ConstStringListRef to provide class implementing the required functions.

class ConstStringListRefAdapter {
  virtual int Size() = 0;
  virtual const std::string Entry(int index) = 0;
}

ConstStringListRef(ConstStringListRefAdapter* adapter);
ConstStringListRef(std::unique_ptr<ConstStringListRefAdapter> adapter);

But I am not totally convinced.

[blackpill0w]

You're right the ConstStringListRefAdapter stills creates a new string each time so that would very bad for performance, what about a vector<std::string_view>? You still have the hit when you compute the size but it's better I think.
I also thought of using vector<std::string*>, I don't know how much change would be required to the existing code, so tell me what you think about the two suggestions.