From fc5575264ffbb14a7c8b13e57fbe85b8f30b6745 Mon Sep 17 00:00:00 2001
From: Silvio Traversaro <pegua1@gmail.com>
Date: Fri, 10 Nov 2023 04:03:11 +0000
Subject: [PATCH] Backport "disambiguate overloads for empty index list" to 3.4
 branch

---
 unsupported/Eigen/CXX11/src/Tensor/TensorMeta.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorMeta.h b/unsupported/Eigen/CXX11/src/Tensor/TensorMeta.h
index a4922e913..75b919839 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorMeta.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorMeta.h
@@ -261,7 +261,7 @@ template <typename Idx> struct IndexPair {
 #ifdef EIGEN_HAS_SFINAE
 namespace internal {
 
-  template<typename IndexType, typename Index, Index... Is>
+  template<typename IndexType, typename Index, Index First, Index... Is>
   EIGEN_CONSTEXPR EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE
   array<Index, 1 + sizeof...(Is)> customIndices2Array(IndexType& idx, numeric_list<Index, First, Is...>) {
     return { static_cast<Index>(idx[First]), static_cast<Index>(idx[Is])... };