https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68061
--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
This bug is still present on trunk when -fconcepts-ts is used, even in C++20
mode:
$ g++ -c 68061.C -std=c++20
$ g++ -c 68061.C -std=c++20 -fconcepts-ts
68061.C:3:1: error: two consecutive ‘[’ shall only introduce an attribute
before ‘[’ token
3 | [[deprecated]] void f(T);
| ^
It also affects [[nodiscard]] and so caused PR 101782.
