https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123080
--- Comment #4 from Egas Ribeiro <egas.g.ribeiro at tecnico dot ulisboa.pt> ---
also here in cp_parser_lambda_declarator_opt:
if (has_param_list)
{
/* Parse optional trailing requires clause. */
trailing_requires_clause = cp_parser_requires_clause_opt (parser, false);
/* The function parameters must be in scope all the way until after the
trailing-return-type in case of decltype. */
pop_bindings_and_leave_scope ();
}
cp_parser_requires_clause_opt seems to mess with the context we were creating
for this lambda. on the implicit template case, it unsets
processing_template_decl.
for the explicit case, it doesn't.
