Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for trunk? Also verified by way of gcc_assert that we never see TEMPLATE_PARM_INDEX here.
-- >8 -- Within a template parameter list, a non-type template parameter pack is represented as a PARM_DECL. But in a couple of spots where we need to deduce an empty argument pack, we test for TEMPLATE_PARM_INDEX (within a template parameter list) instead of for PARM_DECL, which means we end up using TYPE_ARGUMENT_PACK even in the non-type case. This patch fixes this (seemingly harmless) bug. gcc/cp/ChangeLog: * pt.cc (type_unification_real): Test for PARM_DECL instead of TEMPLATE_PARM_INDEX to distinguish a type vs non-type template parameter pack. (type_targs_deducible_from): Likewise. --- gcc/cp/pt.cc | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index 3987ffc509a..d342ab5929a 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -23345,7 +23345,7 @@ type_unification_real (tree tparms, { tree arg; - if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX) + if (TREE_CODE (tparm) == PARM_DECL) { arg = make_node (NONTYPE_ARGUMENT_PACK); TREE_CONSTANT (arg) = 1; @@ -30369,7 +30369,7 @@ type_targs_deducible_from (tree tmpl, tree type) if (template_parameter_pack_p (tparm)) { tree arg; - if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX) + if (TREE_CODE (tparm) == PARM_DECL) { arg = make_node (NONTYPE_ARGUMENT_PACK); TREE_CONSTANT (arg) = 1; -- 2.41.0.363.g5e238546dc