Why does FastDDS/Fast-CDR use eprosima::fastcdr::optional instead of std::optional?

[lancelot-Yagami]

Is there an already existing issue for this?

• I have searched the existing issues

Expected behavior

Hi, thanks for the great work on FastDDS and Fast-CDR.

While reading the documentation about optional members in IDL, I noticed that optional fields are mapped to eprosima::fastcdr::optional<T> instead of std::optional<T>.

If backward compatibility with older C++ standards is required, one possible approach could be:

Use std::optional when C++17 or newer is available

Fall back to eprosima::fastcdr::optional otherwise

Thanks again for your work on this project. I'm asking mainly to understand the design decision and potential future direction.

Current behavior

eprosima::fastcdr::optional<T>

Steps to reproduce

None

Fast DDS version/commit

3.4.2

Platform/Architecture

Ubuntu Focal 20.04 amd64

Transport layer

Default configuration, UDPv4 & SHM

Additional context

No response

XML configuration file

Relevant log output

Network traffic capture

No response