https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83167
--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Patrick Palka <ppa...@gcc.gnu.org>: https://gcc.gnu.org/g:d9965fef40794d548021d2e34844e5fafeca4ce5 commit r14-6350-gd9965fef40794d548021d2e34844e5fafeca4ce5 Author: Patrick Palka <ppa...@redhat.com> Date: Fri Dec 8 16:57:13 2023 -0500 c++: decltype of (non-captured variable) [PR83167] For decltype((x)) within a lambda where x is not captured, we dubiously require that the lambda has a capture default, unlike for decltype(x). But according to [expr.prim.id.unqual]/3 we should just ignore the lambda in this case. This patch narrowly fixes this issue by disabling the capture_decltype handling and falling back to the ordinary handling when the innermost lambda has no capture-default. In fact, we can restrict the special handling to only by-copy lambdas since that's what [expr.prim.id.unqual]/3 is concerned with; for by-ref implicit captures both code paths should give the same result anyway. During review some other issues were discovered which are documented in a new FIXME. PR c++/83167 gcc/cp/ChangeLog: * semantics.cc (capture_decltype): Inline into its only caller ... (finish_decltype_type): ... here. Update nearby comment to refer to recent standard. Add FIXME. Restrict uncaptured variable type transformation to happen only for lambdas with a by-copy capture-default. gcc/testsuite/ChangeLog: * g++.dg/cpp0x/lambda/lambda-decltype4.C: New test.
