Request: Implement 'member-of-pointer' access operator (->) for Rfl types

[Lazrius]

Heya. I was wondering if it would be possible to implement the 'ptr' operator for many of the types to make accessing underlying data structures a bit easier and more in line with the STL.

I know that the dereference operator and the function '()' operator is already on a many of these, but I think that '->' would also be a very helpful one to have. It wont really help when you have many nested types, but I think (personally) it's a lot more intuitive to those unfamiliar with the library.

struct SpecialData
{
    std::string helloWorld = "hello world";
};

rfl::Skip<SpecialData> test{{}};

auto abc = test->helloWorld; // I think that this is more intuitive than the one below
auto dce = test().helloWorld;

Additionally, I think that it would map similar to the existing std::optional and rfl::Result types, which keeps things consistent 🙂

If you agree, I am more than happy to make the changes and put in a PR.