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. */
+ gcc_assert (ARGUMENT_PACK_INCOMPLETE_P (oldelt));
+ gcc_assert (ARGUMENT_PACK_ARGS (oldelt)
+ == ARGUMENT_PACK_EXPLICIT_ARGS (oldelt));
+
+ tree explicit_pack = ARGUMENT_PACK_ARGS (oldelt);
+ tree deduced_pack = ARGUMENT_PACK_ARGS (elt);
+
+ if (TREE_VEC_LENGTH (deduced_pack)
+ < TREE_VEC_LENGTH (explicit_pack))
+ return 0;
+
+ for (int j = 0; j < TREE_VEC_LENGTH (explicit_pack); j++)
+ if (!template_args_equal (TREE_VEC_ELT (explicit_pack, j),
+ TREE_VEC_ELT (deduced_pack, j)))
+ return 0;
+ }
else if (oldelt && !template_args_equal (oldelt, elt))
return 0;
}
diff --git a/gcc/testsuite/g++.dg/cpp0x/pr69056.C
b/gcc/testsuite/g++.dg/cpp0x/pr69056.C
new file mode 100644
index 0000000..ab4e071
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/pr69056.C
@@ -0,0 +1,30 @@
+// { dg-do compile { target c++11 } }
+// PR c++/69056
+
+template <typename T, typename... Args>
+void resolver(int (*) (T, Args...));
+
+int funcA(int, float) { return 0; }
+int funcA(double) { return 0; }
+
+int funcB(int, float, char) { return 0; }
+int funcB(int, bool) { return 0; }
+int funcB(double) { return 0; }
+
+int funcC(int) { return 0; }
+int funcC(double) { return 0; }
+
+void
+foo (void)
+{
+ resolver (&funcA); // { dg-error "no match" }
+ resolver<int> (&funcA);
+ resolver<double> (&funcA);
+
+ resolver<int> (&funcB); // { dg-error "no match" }
+ resolver<int, char> (&funcB); // { dg-error "no match" }
+ resolver<int, float> (&funcB);
+
+ resolver<int> (&funcC);
+ resolver<int, float> (&funcC); // { dg-error "no match" }
+}
--
2.7.0.rc1.98.gacf58d0.dirty
