See <https://wg21.link/P3491R3>.
Implemented on the reflection branch.
https://forge.sourceware.org/marek/gcc/src/branch/reflection
Implemented with commit r16-6808-g4b0e94b394fa38cdc3431f3cfb333b85373bd948 Author: Marek Polacek <polacek@redhat.com> Date: Wed Jan 14 11:37:39 2026 -0500 c++: C++26 Reflection [PR120775] This patch implements C++26 Reflection as specified by P2996R13, which allows users to perform magic. This patch also implements related papers: Annotations for Reflection (P3394R4), Splicing a base class subobject (P3293R3), define_static_{string,object,array} (P3491R3), Function Parameter Reflection (P3096R12). (I already implemented consteval blocks back in July.) (We do not yet implement P3795.) ...