[Bug c++/66426] New: ICE: unexpected expression ‘int?=(Constructible())...=?UTF-8?Q?’ of kind expr_pack_expansion

[jamrial at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66426

            Bug ID: 66426
           Summary: ICE: unexpected expression ‘int(Constructible())...’
                    of kind expr_pack_expansion
           Product: gcc
           Version: 4.9.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jamrial at gmail dot com
  Target Milestone: ---

[jamrial@archVM ~]$ cat zip.c
template <typename> struct A;
template <bool> struct enable_if;
template <typename T, T> struct B;
template <bool... Bools> using and_c = A<B<bool, Bools || true...>>;
template <typename...> using Constructible = int;
template <typename... Ts> struct common_tuple {
  template <
      typename... Us,
      typename enable_if<and_c<(int)Constructible<Ts, Us>()...>::value>::type>
};

[jamrial@archVM ~]$ g++-trunk -O2 -std=c++11 -c zip2.c
zip2.c:10:1: error: expected unqualified-id before ‘}’ token
 };
 ^

[jamrial@archVM ~]$ g++-5.1 -O2 -std=c++11 -c zip2.c
zip2.c:10:1: error: expected unqualified-id before ‘}’ token
 };
 ^

[jamrial@archVM ~]$ g++-4.9 -O2 -std=c++11 -c zip.c
zip.c:9:63: internal compiler error: unexpected expression
‘int(Constructible())...’ of kind expr_pack_expansion
       typename enable_if<and_c<(int)Constructible<Ts, Us>()...>::value>::type>
                                                               ^
0x61cbd6 cxx_eval_constant_expression
        /home/jamrial/gcc-4.9-20150603/gcc/cp/semantics.c:9833
0x61e5b6 cxx_eval_outermost_constant_expr
        /home/jamrial/gcc-4.9-20150603/gcc/cp/semantics.c:9853
0x585cb0 convert_nontype_argument
        /home/jamrial/gcc-4.9-20150603/gcc/cp/pt.c:5698
0x585cb0 convert_template_argument
        /home/jamrial/gcc-4.9-20150603/gcc/cp/pt.c:6590
0x582252 coerce_template_parameter_pack
        /home/jamrial/gcc-4.9-20150603/gcc/cp/pt.c:6713
0x582252 coerce_template_parms
        /home/jamrial/gcc-4.9-20150603/gcc/cp/pt.c:6922
0x586c70 lookup_template_class_1
        /home/jamrial/gcc-4.9-20150603/gcc/cp/pt.c:7594
0x586c70 lookup_template_class(tree_node*, tree_node*, tree_node*, tree_node*,
int, int)
        /home/jamrial/gcc-4.9-20150603/gcc/cp/pt.c:7895
0x6149b2 finish_template_type(tree_node*, tree_node*, int)
        /home/jamrial/gcc-4.9-20150603/gcc/cp/semantics.c:2969
0x5d63fa cp_parser_template_id
        /home/jamrial/gcc-4.9-20150603/gcc/cp/parser.c:13464
0x5d6613 cp_parser_class_name
        /home/jamrial/gcc-4.9-20150603/gcc/cp/parser.c:19195
0x5cc673 cp_parser_qualifying_entity
        /home/jamrial/gcc-4.9-20150603/gcc/cp/parser.c:5538
0x5cc673 cp_parser_nested_name_specifier_opt
        /home/jamrial/gcc-4.9-20150603/gcc/cp/parser.c:5263
0x5e0ee2 cp_parser_simple_type_specifier
        /home/jamrial/gcc-4.9-20150603/gcc/cp/parser.c:14666
0x5c3ebd cp_parser_type_specifier
        /home/jamrial/gcc-4.9-20150603/gcc/cp/parser.c:14412
0x5c65cb cp_parser_type_specifier_seq
        /home/jamrial/gcc-4.9-20150603/gcc/cp/parser.c:18137
0x5d4ee2 cp_parser_type_id_1
        /home/jamrial/gcc-4.9-20150603/gcc/cp/parser.c:18010
0x5d4fde cp_parser_template_type_arg
        /home/jamrial/gcc-4.9-20150603/gcc/cp/parser.c:18059
0x5d51d8 cp_parser_template_argument
        /home/jamrial/gcc-4.9-20150603/gcc/cp/parser.c:13840
0x5d51d8 cp_parser_template_argument_list
        /home/jamrial/gcc-4.9-20150603/gcc/cp/parser.c:13750
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.


Testcase based on the one from Comment 2 of pr66405.