Empty base class optimisation (EBCO) std::tuple

[jt-9]

Is Microsoft STL tuple empty class optimisation disabled or not implemented?
I have made a simple test with tuple sizeof and, it appears, MSVC compiler even with /O1 (small size)
does not apply empty base class optimisation in contrast to gcc and clang.
Microsoft STL std::unique_ptr implementation internally relies on _Compressed_pair which supports EBCO, but not std::tuple
I am working on utility class similar to std::unique_ptr but with different purpose link

What would You suggest as a cross-platform standard solution to hold members efficiently? Thank you.

[StephanTLavavej]

Not implemented. (And we can't implement that without breaking ABI; see #197.)

[[no_unique_address]] on other platforms and [[msvc::no_unique_address]] on MSVC can avoid paying space for data members without requiring the elaborate base class scheme.

[jt-9]

Thank you.
Missed that, sorry