[Bug c++/65525] ICE: sorry, unimplemented: unexpected AST of kind mem_ref (-std=c++14, ICE: in potential_constant_expression_1, at cp/constexpr.c:4432)

["rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65525

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Run till exit from #0  0x00000000012bf93a in build2_stat (code=MEM_REF, 
    tt=<array_type 0x7ffff6a35f18>, arg0=<addr_expr 0x7ffff6a39760>, 
    arg1=<integer_cst 0x7ffff6a33228>)
    at /space/rguenther/src/svn/trunk/gcc/tree.c:4385
0x00000000006f8b40 in build_over_call (cand=0x24f7aa0, flags=1, complain=3)
    at /space/rguenther/src/svn/trunk/gcc/cp/call.c:7456
7456              t = build2 (MODIFY_EXPR, void_type_node,
Value returned is $9 = (tree_node *) 0x7ffff6a37758
(gdb) l
7451              array_type = build_array_type (char_type_node,
7452                                             build_index_type
7453                                               (size_binop (MINUS_EXPR,
7454                                                            arg2, size_int
(1))));
7455              alias_set = build_int_cst (build_pointer_type (type), 0);
7456              t = build2 (MODIFY_EXPR, void_type_node,
7457                          build2 (MEM_REF, array_type, arg0, alias_set),
7458                          build2 (MEM_REF, array_type, arg, alias_set));
7459              val = build2 (COMPOUND_EXPR, TREE_TYPE (to), t, to);

so the C++ FE even builds this itself.