https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71833
Martin Sebor <msebor at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2016-07-11
CC| |msebor at gcc dot gnu.org
Summary|ICE on valid C++11 code |[5/6/7 regression] ICE on
|with nested variadic |valid C++11 code with
|templates: tree check: |nested variadic templates:
|accessed elt 0 of tree_vec |tree check: accessed elt 0
|with 1 elts in |of tree_vec with 1 elts in
|coerce_template_parameter_p |coerce_template_parameter_p
|ack, at cp/pt.c:7439 |ack, at cp/pt.c:7439
Ever confirmed|0 |1
Known to fail| |4.9.3, 5.3.0, 6.1.0, 7.0
--- Comment #1 from Martin Sebor <msebor at gcc dot gnu.org> ---
Confirmed with r208178 committed in the 4.9.0 cycle as the root cause of the
ICE.
r208178 | jason | 2014-02-26 12:08:20 -0500 (Wed, 26 Feb 2014) | 10 lines
PR c++/54440
* pt.c (get_template_parm_index): New.
(fixed_parameter_pack_p_1, fixed_parameter_pack_p): New.
(process_template_parm): Allow bare packs in template template
parm template parms.
(coerce_template_parameter_pack): Handle fixed template template
parm packs and fixed packs not at the end of the parm list.
(coerce_template_parms): Handle template parm packs not at the end
of the parm list.
(gen_elem_of_pack_expansion_instantiation): Handle a decl expansion.
r208177 rejects the test case with the error below. So does EDG eccp 4.11,
with a similar error. But Clang accepts it, so I'm not sure whether or not
it's valid without some studying of the standard.
error: parameter pack ‘<anonymous>’ must be at the end of the template
parameter list
template < Ts ..., typename ... Us > struct B {};
^
t.C:8:7: error: ‘B’ in ‘struct A<>’ does not name a template type
A <>::B < int > e;
^
