[FPR] Some feedback

From: Andrzej Krzemienski (akrzemi1_at_[hidden])
Date: 2020-10-02 22:42:50

Hi Everyone,
Not sure if I will be able to provide a decent review, so I wanted to at
least share some thoughts.

1. Do not use "reflection" in the library name. "Reflection" means "any
information I could ever need about any part of the program". In
particular, people might expect that you will be able to give the class
member names; you cannot, and they will call it a bug in the library,
because it implied that it would be able to do this, as this is what you
expect from reflection.

What this library does is to give a tuple-like access to class members
(plus a number of things atop of this). Maybe it should be called
Tuple-like Element Access (TEA)?

2. The library can only provide tuple-like access to classes that meet
certain criteria, but these criteria are not obvious. Calling it an
aggregate-initializable struct is not good enough:

```
struct B {};
struct D : B {
  int i, j;
};
```

Struct D is an aggregate (in C++20) and can be aggregate-initialized with
three elements, but will not work with the library. I suggest you list
requirements and give them a name. Bjarne Stroustrup called something
similar a "flat":
https://www.youtube.com/watch?v=ERzENfQ51Ck&feature=youtu.be&t=376
but I am not sure if this is the right one. Maybe "simple aggregate".

This would help users prepare for what to expect. I do not know if this can
be statically tested (like if a class has any base) but this does not
matter as long as the requirements are listed in the docs. This concept is
core to the library.

3. Does this library bring any value for arrays? It works for arrays, but
arrays already provide index-based element access.

4. Thank you for writing and sharing this library. I really like it.

Regards,
&rzej;