No, we don’t.


An implementation that wants to be backward compatible with the pre-module headers, can implement the modular view via ‘export import’ of header units.


An implementation that wants to offer a certain guarantees vis-à-vis ODR can exploit the strong ownership facility.


In either case, a modular view of the standard library can offer a more robust support for more environments than today anarchic standard headers.


From: Ext <> On Behalf Of Bryce Adelstein Lelbach aka wash via Ext
Sent: Sunday, March 8, 2020 2:01 PM
To: C++ Library Evolution Working Group <>; Evolution Working Group mailing list <>;; ISO C++ Tooling Study Group <>
Cc: Bryce Adelstein Lelbach aka wash <>
Subject: [isocpp-ext] Modularization of the standard library and ABI stability


Do we have any ABI stability concerns regarding modularizing the standard library? Certainly for strong module ownership implementations, this is a concern, but for weak module ownership implementations it may be a concern too, because the mangling of internal implementation details with module linkage would change.


Can implementations overcome this with special hacks for the standard library that preserve the old mangled names?