On 05/10/09 11:20, cppljevans at suddenlink dot net wrote:
When compile trysto expand:
: seq
< integral_c
< Integral
, Vals
>...
the error diagnostic prints integral_c<T, val> instead of
integral_c<Integral,Vals>. The integral_constant template
is derived from integral_c and does have T and val args:
struct integral_constant:public mpl::integral_c < T, val >
However, when that is replaced with:
struct integral_constant;//:public mpl::integral_c < T, val >
Compilation succeeds.
When cp_tree_equal in cp/tree.c at around line 1903 is changed to:
case TEMPLATE_PARM_INDEX:
{
if (TEMPLATE_PARM_IDX (t1) != TEMPLATE_PARM_IDX (t2)) return false;
if (TEMPLATE_PARM_LEVEL (t1) != TEMPLATE_PARM_LEVEL (t2)) return false;
#if 1
if (TEMPLATE_PARM_PARAMETER_PACK (t1) != TEMPLATE_PARM_PARAMETER_PACK
(t2)) return false;
#endif
return same_type_p ( TREE_TYPE (TEMPLATE_PARM_DECL (t1)),
TREE_TYPE (TEMPLATE_PARM_DECL (t2)));
}
the test passes. Apparently, when the test:
if (comp_template_args (TREE_PURPOSE (spec), args))
at around line pt.c:962 is executed, it passes when it shouldn't
and selects a previous instantiation with different value for
TEMPLATE_PARM_PARAMETER_PACK. This different instantiation leads
to the failure of the test in:
if (TEMPLATE_PARM_PARAMETER_PACK (t))
parameter_pack_p = true;
at round pt.c:2463 which causes the error message.
