Initializing from an initializer list, but without {{{{{{{{ … }}}}}}}}?

Question

I recently stumbles across some problem with initializer lists. Consider a program that stores map-like data

struct MyMapLike {
  MyMapLike(std::map

        

Answer 1

Wouldn't something like this give the desired effect (MyMapLike can be constructed in any way that std::map can, but does not implicitly convert to std::map)?

struct MyMapLike : private std::map
{
    using map::map;
};

If it absolutely positively has to be a member, maybe use constructor perfect forwarding (I'm not sure about the exact syntax) along the lines of:

struct MyMapLike
{
    template
    MyMapLike(Initializers... init, decltype(new std::map(...init)) = 0)
      : data(...init)
    { }

private:
    std::map data;
};