[Bug c++/88313] generic lambda in default template argument

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88313

--- Comment #5 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Patrick Palka <ppalka@gcc.gnu.org>:

https://gcc.gnu.org/g:72a7ab891ae0061841c4eb641ef6ab7719bf0369

commit r15-2387-g72a7ab891ae0061841c4eb641ef6ab7719bf0369
Author: Patrick Palka <ppalka@redhat.com>
Date:   Mon Jul 29 16:37:19 2024 -0400

    c++: generic lambda in default template argument [PR88313]

    Here we're rejecting the generic lambda inside the default template
    argument ultimately because auto_is_implicit_function_template_parm_p
    doesn't get set during parsing of the lambda's parameter list, due
    to the !processing_template_parmlist restriction.  But when parsing a
    lambda parameter list we should always set that flag regardless of where
    the lambda appears.  This patch makes sure of this via a local lambda_p
    flag.

            PR c++/88313

    gcc/cp/ChangeLog:

            * parser.cc (cp_parser_lambda_declarator_opt): Pass
            lambda_p=true to cp_parser_parameter_declaration_clause.
            (cp_parser_direct_declarator): Pass lambda_p=false to
            to cp_parser_parameter_declaration_clause.
            (cp_parser_parameter_declaration_clause): Add bool lambda_p
            parameter.  Consider lambda_p instead of current_class_type
            when setting parser->auto_is_implicit_function_template_parm_p.
            Don't consider processing_template_parmlist.
            (cp_parser_requirement_parameter_list): Pass lambda_p=false
            to cp_parser_parameter_declaration_clause.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp2a/lambda-targ6.C: New test.

    Reviewed-by: Jason Merrill <jason@redhat.com>