================
@@ -1072,12 +1072,25 @@ BuildDeductionGuideForTypeAlias(Sema &SemaRef,
AliasRhsTemplateArgs, TDeduceInfo, DeduceResults,
/*NumberOfArgumentsMustMatch=*/false);
+ static auto IsNonDeducedArgument = [&](const DeducedTemplateArgument &TA) {
+ // The following cases indicate the template argument is non-deducible:
+ // 1. The result is null. E.g. When it comes from a default template
+ // argument that doesn't appear in the alias declaration.
+ // 2. The template parameter is a pack and that cannot be deduced from
+ // the arguments within the alias declaration.
+ // Non-deducible template parameters will persist in the transformed
+ // deduction guide.
+ return TA.isNull() || (TA.getKind() == TemplateArgument::Pack &&
+ TA.pack_size() == 1 && TA.pack_begin()->isNull());
----------------
zyn0217 wrote:
(Oh silly me I thought I have asked myself the same question but I quickly
forgot to get to it again...)
Yes you're right, we should traverse each element of the pack. I added a test
case to reflect that:
https://github.com/llvm/llvm-project/pull/132061/commits/74e4444c072d116b48147ba06fd45db57fbbcc03
https://github.com/llvm/llvm-project/pull/132061
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
