[Bug c++/117435] [contracts] capture of a function parm in a lambda in a contract does not work

[iains at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117435

--- Comment #3 from Iain Sandoe <iains at gcc dot gnu.org> ---
the cxx2a variant is now irrelevant, GCC no longer supports the attribute
syntax.