https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94483
--- Comment #3 from CVS 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:a28edad3da5c59f09565d3d42e20be1a924986c4 commit r10-7780-ga28edad3da5c59f09565d3d42e20be1a924986c4 Author: Patrick Palka <ppa...@redhat.com> Date: Thu Apr 16 10:28:23 2020 -0400 c++: Non-type-dependent variadic lambda init-capture [PR94483] In this PR, we're ICEing on a use of an 'int... a' template parameter pack as part of the variadic lambda init-capture [...z=a]. The unexpected thing about this variadic init-capture is that it is not type-dependent, and so the call to do_auto_deduction from lambda_capture_field_type actually resolves its type to 'int' instead of exiting early like it does for a type-dependent variadic initializer. This later confuses add_capture which, according to one of its comments, assumes that 'type' is always 'auto' for a variadic init-capture. The simplest fix (and the approach that this patch takes) seems to be to avoid doing auto deduction in lambda_capture_field_type when the initializer uses parameter packs, so that we always return 'auto' even in the non-type-dependent case. gcc/cp/ChangeLog: PR c++/94483 * lambda.c (lambda_capture_field_type): Avoid doing auto deduction if the explicit initializer has parameter packs. gcc/testsuite/ChangeLog: PR c++/94483 * g++.dg/cpp2a/lambda-pack-init5.C: New test.
