https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99631
--- Comment #12 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-13 branch has been updated by Patrick Palka <ppa...@gcc.gnu.org>: https://gcc.gnu.org/g:b9e02590f7d35f1f8e8e95ab1f2e30f24113f551 commit r13-7835-gb9e02590f7d35f1f8e8e95ab1f2e30f24113f551 Author: Patrick Palka <ppa...@redhat.com> Date: Tue Sep 19 08:21:05 2023 -0400 c++: constness of decltype of NTTP object [PR99631] This corrects resolving decltype of a (class) NTTP object as per [dcl.type.decltype]/1.2 and [temp.param]/6 in the type-dependent case. Note that in the non-dependent case we resolve the decltype ahead of time, in which case finish_decltype_type drops the const VIEW_CONVERT_EXPR wrapper around the TEMPLATE_PARM_INDEX, and the latter has the desired non-const type. In the type-dependent case, at instantiation time tsubst drops the VIEW_CONVERT_EXPR since the substituted NTTP is the already-const object created by get_template_parm_object. So in this case finish_decltype_type sees the const object, which this patch now adds special handling for. PR c++/99631 gcc/cp/ChangeLog: * semantics.cc (finish_decltype_type): For an NTTP object, return its type modulo cv-quals. gcc/testsuite/ChangeLog: * g++.dg/cpp2a/nontype-class60.C: New test. (cherry picked from commit ddd064e3571c4a9e6258c75eba65585a07367712)
