On Sun, Dec 27, 2015 at 12:05 PM, Patrick Palka <patrick@parcs.ath.cx> wrote:
> On Sun, Dec 27, 2015 at 12:02 PM, Patrick Palka <patrick@parcs.ath.cx> wrote:
>> In try_one_overload(), it should not be a deduction failure if we
>> deduced more arguments of an argument pack than were explicitly
>> specified (as long as the arguments are otherwise equivalent).
>>
>> This patch makes try_one_overload() manually check the argument packs,
>> to permit such a case.
>>
>> Bootstrap + regtest in progress on x86_64-pc-linux-gnu, will also test
>> against Boost. Is this OK to commit if testing succeeds?
>>
>> gcc/cp/ChangeLog:
>>
>> PR c++/69052
>> * pt.c (try_one_overload): Handle comparing argument packs so
>> that there is no conflict if we deduced more arguments of an
>> argument pack than were explicitly specified.
>>
>> gcc/testsuite/ChangeLog:
>>
>> PR c++/69052
>> g++.dg/cpp0x/pr69056.C: New test.
>> ---
>> gcc/cp/pt.c | 21 +++++++++++++++++++++
>> gcc/testsuite/g++.dg/cpp0x/pr69056.C | 30 ++++++++++++++++++++++++++++++
>> 2 files changed, 51 insertions(+)
>> create mode 100644 gcc/testsuite/g++.dg/cpp0x/pr69056.C
>>
>> diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
>> index ff16b7c..cdbfadd 100644
>> --- a/gcc/cp/pt.c
>> +++ b/gcc/cp/pt.c
>> @@ -18694,6 +18694,27 @@ try_one_overload (tree tparms,
>> template args used in the function parm list with our own
>> template parms. Discard them. */
>> TREE_VEC_ELT (tempargs, i) = NULL_TREE;
>> + else if (oldelt && ARGUMENT_PACK_P (oldelt))
>> + {
>> + /* Check that the deduced argument at each index is equivalent to the
>> + corresponding explicit argument. We may have deduced more
>> + arguments than were explicitly specified, and that's OK. */
>
> Oops, I forgot to --amend a clarity change to the above comment. It
> should read:
>
> /* Check that the argument at each index of the deduced argument pack
> is equivalent to the corresponding explicitly specified argument.
> We may have deduced more arguments than were explicitly specified,
> and that's OK. */
... And I just realize I have been referring to the wrong PR :( It
should be c++/69056 not 69052... Sorry.
I suppose I will just resend a fixed version of this patch in a new
thread. Please ignore this one.