Optional struct member via sentinel values about flatdata HOT 4 CLOSED

I like the idea.

What would be the extended interface of A to work with null values? I guess, when creating A, x will be INVALID_XYZ instead of 0 by default. What about checks for is_null? Not sure, how to express this.

If we think about Rust implementation, then this x is an optional field. Not sure, it is important what is the actual value of INVALID_XYZ. In that case, the getter A::x() would just return Option<u32>. What about C++/Python?

from flatdata.

Good point about the default value: We only support 0s at the moment. So null would not be the default in many cases.

C++ does not have optional yet (at least until 17), so we either role our own or wait for 17. Python has Optional.

from flatdata.

C++ does not have optional yet (at least until 17), so we either role our own or wait for 17. Python has Optional.

We could provide some functions on the interface of A to check if x is null, something like x_is_null. However, this could lead to very long and non-discoverable names.

from flatdata.

Done

from flatdata.