Tested x86_64-pc-linux-gnu, applying to trunk. -- 8< --
As Jakub pointed out, the real problem here is that in a partial substitution we're forgetting the conversion to the type of the non-type template argument, because maybe_convert_nontype_argument doesn't do anything with value-dependent arguments. I'm experimenting with changing that, but in the meantime we can work around it here. PR c++/111357 gcc/cp/ChangeLog: * pt.cc (expand_integer_pack): Use IMPLICIT_CONV_EXPR. --- gcc/cp/pt.cc | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index ea5379098a5..73ac1cb597c 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -3769,6 +3769,13 @@ expand_integer_pack (tree call, tree args, tsubst_flags_t complain, { if (hi != ohi) { + /* Work around maybe_convert_nontype_argument not doing this for + dependent arguments. Don't use IMPLICIT_CONV_EXPR_NONTYPE_ARG + because that will make tsubst_copy_and_build ignore it. */ + tree type = tsubst (TREE_TYPE (ohi), args, complain, in_decl); + if (!TREE_TYPE (hi) || !same_type_p (type, TREE_TYPE (hi))) + hi = build1 (IMPLICIT_CONV_EXPR, type, hi); + call = copy_node (call); CALL_EXPR_ARG (call, 0) = hi; } @@ -3779,8 +3786,6 @@ expand_integer_pack (tree call, tree args, tsubst_flags_t complain, } else { - hi = perform_implicit_conversion_flags (integer_type_node, hi, complain, - LOOKUP_IMPLICIT); hi = instantiate_non_dependent_expr (hi, complain); hi = cxx_constant_value (hi, complain); int len = valid_constant_size_p (hi) ? tree_to_shwi (hi) : -1; base-commit: 22cda0ca5fb406f22925bbf51ab152a958e3319d -- 2.39.3