[odb-users] Is C++17 supported?

[علی دانش]

Hi Boris!
According to this link https://www.codesynthesis.com/pipermail/odb-users/2018-March/003973.html, c++17 must be supported; But:

C:\odb-2.5.0-b.3-i686-windows\bin>odb --std c++17
invalid value 'c++17' for option '--std'

And when I include “optional” in a header file, it generates an error:
fatal error: optional: No such file or directory

Best regards,
Ali