[Bug libstdc++/100226] [11/12 Regression] c++/11/bits/stl_tree.h:770:8: error: static assertion failed: comparison object must be invocable as const

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100226

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
The static assert was added intentionally, the comparison function used with
the container must have a const-qualified operator().

I would check that in the nurses code first.