diff --git a/include/experimental/__p2630_bits/submdspan_extents.hpp b/include/experimental/__p2630_bits/submdspan_extents.hpp
index c3b2f78f..779a9316 100644
--- a/include/experimental/__p2630_bits/submdspan_extents.hpp
+++ b/include/experimental/__p2630_bits/submdspan_extents.hpp
@@ -17,6 +17,7 @@
 #pragma once
 
 #include <tuple>
+#include <complex>
 
 #include "strided_slice.hpp"
 namespace MDSPAN_IMPL_STANDARD_NAMESPACE {
@@ -52,6 +53,31 @@ template <class OffsetType, class ExtentType, class StrideType>
 struct is_strided_slice<
     strided_slice<OffsetType, ExtentType, StrideType>> : std::true_type {};
 
+// Helper for identifying valid pair like things
+template <class T, class IndexType> struct index_pair_like : std::false_type {};
+
+template <class IdxT1, class IdxT2, class IndexType>
+struct index_pair_like<std::pair<IdxT1, IdxT2>, IndexType> {
+  static constexpr bool value = std::is_convertible_v<IdxT1, IndexType> &&
+                                std::is_convertible_v<IdxT2, IndexType>;
+};
+
+template <class IdxT1, class IdxT2, class IndexType>
+struct index_pair_like<std::tuple<IdxT1, IdxT2>, IndexType> {
+  static constexpr bool value = std::is_convertible_v<IdxT1, IndexType> &&
+                                std::is_convertible_v<IdxT2, IndexType>;
+};
+
+template <class IdxT, class IndexType>
+struct index_pair_like<std::complex<IdxT>, IndexType> {
+  static constexpr bool value = std::is_convertible_v<IdxT, IndexType>;
+};
+
+template <class IdxT, class IndexType>
+struct index_pair_like<std::array<IdxT, 2>, IndexType> {
+  static constexpr bool value = std::is_convertible_v<IdxT, IndexType>;
+};
+
 // first_of(slice): getting begin of slice specifier range
 MDSPAN_TEMPLATE_REQUIRES(
   class Integral,
@@ -70,13 +96,19 @@ first_of(const ::MDSPAN_IMPL_STANDARD_NAMESPACE::full_extent_t &) {
 
 MDSPAN_TEMPLATE_REQUIRES(
   class Slice,
-  /* requires */(std::is_convertible_v<Slice, std::tuple<size_t, size_t>>)
+  /* requires */(index_pair_like<Slice, size_t>::value)
 )
 MDSPAN_INLINE_FUNCTION
 constexpr auto first_of(const Slice &i) {
   return std::get<0>(i);
 }
 
+template<class T>
+MDSPAN_INLINE_FUNCTION
+constexpr auto first_of(const std::complex<T> &i) {
+  return i.real();
+}
+
 template <class OffsetType, class ExtentType, class StrideType>
 MDSPAN_INLINE_FUNCTION
 constexpr OffsetType
@@ -100,7 +132,7 @@ constexpr Integral
 
 MDSPAN_TEMPLATE_REQUIRES(
   size_t k, class Extents, class Slice,
-  /* requires */(std::is_convertible_v<Slice, std::tuple<size_t, size_t>>)
+  /* requires */(index_pair_like<Slice, size_t>::value)
 )
 MDSPAN_INLINE_FUNCTION
 constexpr auto last_of(std::integral_constant<size_t, k>, const Extents &,
@@ -108,6 +140,12 @@ constexpr auto last_of(std::integral_constant<size_t, k>, const Extents &,
   return std::get<1>(i);
 }
 
+template<size_t k, class Extents, class T>
+MDSPAN_INLINE_FUNCTION
+constexpr auto last_of(std::integral_constant<size_t, k>, const Extents &, const std::complex<T> &i) {
+  return i.imag();
+}
+
 // Suppress spurious warning with NVCC about no return statement.
 // This is a known issue in NVCC and NVC++
 // Depending on the CUDA and GCC version we need both the builtin
diff --git a/include/experimental/__p2630_bits/submdspan_mapping.hpp b/include/experimental/__p2630_bits/submdspan_mapping.hpp
index e1390fde..69762e44 100644
--- a/include/experimental/__p2630_bits/submdspan_mapping.hpp
+++ b/include/experimental/__p2630_bits/submdspan_mapping.hpp
@@ -98,8 +98,7 @@ template<class SliceSpecifier, class IndexType>
 struct is_range_slice {
   constexpr static bool value =
     std::is_same_v<SliceSpecifier, full_extent_t> ||
-    std::is_convertible_v<SliceSpecifier,
-                          std::tuple<IndexType, IndexType>>;
+    index_pair_like<SliceSpecifier, IndexType>::value;
 };
 
 template<class SliceSpecifier, class IndexType>
diff --git a/include/experimental/__p2642_bits/layout_padded.hpp b/include/experimental/__p2642_bits/layout_padded.hpp
index ef10e0ed..1502489a 100644
--- a/include/experimental/__p2642_bits/layout_padded.hpp
+++ b/include/experimental/__p2642_bits/layout_padded.hpp
@@ -95,6 +95,7 @@ struct padded_extent {
   using static_array_type = typename static_array_type_for_padded_extent<
       padding_value, _Extents, _ExtentToPadIdx, _Extents::rank()>::type;
 
+  MDSPAN_INLINE_FUNCTION
   static constexpr auto static_value() { return static_array_type::static_value(0); }
 
   MDSPAN_INLINE_FUNCTION
@@ -203,7 +204,7 @@ class layout_left_padded<PaddingValue>::mapping {
   }
 
 public:
-#if !MDSPAN_HAS_CXX_20
+#if !MDSPAN_HAS_CXX_20 || defined(__NVCC__)
   MDSPAN_INLINE_FUNCTION_DEFAULTED
   constexpr mapping()
       : mapping(extents_type{})
@@ -347,7 +348,7 @@ class layout_left_padded<PaddingValue>::mapping {
   MDSPAN_INLINE_FUNCTION
   constexpr mapping(const _Mapping &other_mapping) noexcept
       : padded_stride(padded_stride_type::init_padding(
-            other_mapping.extents(),
+            static_cast<extents_type>(other_mapping.extents()),
             other_mapping.extents().extent(extent_to_pad_idx))),
         exts(other_mapping.extents()) {}
 
@@ -566,7 +567,7 @@ class layout_right_padded<PaddingValue>::mapping {
   }
 
 public:
-#if !MDSPAN_HAS_CXX_20
+#if !MDSPAN_HAS_CXX_20 || defined(__NVCC__)
   MDSPAN_INLINE_FUNCTION_DEFAULTED
       constexpr mapping()
       : mapping(extents_type{})
@@ -707,7 +708,7 @@ class layout_right_padded<PaddingValue>::mapping {
   MDSPAN_INLINE_FUNCTION
   constexpr mapping(const _Mapping &other_mapping) noexcept
       : padded_stride(padded_stride_type::init_padding(
-            other_mapping.extents(),
+            static_cast<extents_type>(other_mapping.extents()),
             other_mapping.extents().extent(extent_to_pad_idx))),
         exts(other_mapping.extents()) {}
 
diff --git a/tests/test_layout_padded_left.cpp b/tests/test_layout_padded_left.cpp
index 2e7fe546..88a36a00 100644
--- a/tests/test_layout_padded_left.cpp
+++ b/tests/test_layout_padded_left.cpp
@@ -296,6 +296,8 @@ TEST(LayoutLeftTests, construction)
   ASSERT_EQ((KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t, 3>>(KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t, 3>>()).padded_stride.value(0)), 0);
   ASSERT_EQ((KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t, 4, 7>>(KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t, 4, 7>>()).extents()), (Kokkos::extents<std::size_t, 4, 7>()));
   ASSERT_EQ((KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t, 4, 7>>(KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t, 4, 7>>()).padded_stride.value(0)), 4);
+  ASSERT_EQ((KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t, 4, 7>>(KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t, Kokkos::dynamic_extent, 7>>(Kokkos::extents<std::size_t, Kokkos::dynamic_extent, 7>(4))).extents()), (Kokkos::extents<std::size_t, 4, 7>()));
+  ASSERT_EQ((KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t, 4, 7>>(KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t, Kokkos::dynamic_extent, 7>>(Kokkos::extents<std::size_t, Kokkos::dynamic_extent, 7>(4))).padded_stride.value(0)), 4);
   ASSERT_EQ((KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t, Kokkos::dynamic_extent, 7>>(KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t, 4, 7>>()).extents()), (Kokkos::extents<std::size_t, 4, 7>()));
   ASSERT_EQ((KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t, Kokkos::dynamic_extent, 7>>(KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t, 4, 7>>()).padded_stride.value(0)), 4);
 
@@ -311,6 +313,8 @@ TEST(LayoutLeftTests, construction)
   ASSERT_EQ(KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t>>(KokkosEx::layout_right_padded<4>::mapping<Kokkos::extents<std::size_t>>()).extents(), Kokkos::extents<std::size_t>());
   ASSERT_EQ((KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t, 3>>(KokkosEx::layout_right_padded<4>::mapping<Kokkos::extents<std::size_t, 3>>()).extents()), (Kokkos::extents<std::size_t, 3>()));
   ASSERT_EQ((KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t, 3>>(KokkosEx::layout_right_padded<4>::mapping<Kokkos::extents<std::size_t, 3>>()).padded_stride.value(0)), 0);
+  ASSERT_EQ((KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t, 3>>(KokkosEx::layout_right_padded<4>::mapping<Kokkos::extents<std::size_t, Kokkos::dynamic_extent>>(Kokkos::dextents<size_t,1>(3))).extents()), (Kokkos::extents<std::size_t, 3>()));
+  ASSERT_EQ((KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t, 3>>(KokkosEx::layout_right_padded<4>::mapping<Kokkos::extents<std::size_t, Kokkos::dynamic_extent>>(Kokkos::dextents<size_t,1>(3))).padded_stride.value(0)), 0);
   ASSERT_EQ((KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t, 3>>(KokkosEx::layout_right_padded<Kokkos::dynamic_extent>::mapping<Kokkos::extents<std::size_t, 3>>({}, 4)).extents()), (Kokkos::extents<std::size_t, 3>()));
   ASSERT_EQ((KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t, 3>>(KokkosEx::layout_right_padded<Kokkos::dynamic_extent>::mapping<Kokkos::extents<std::size_t, 3>>({}, 4)).padded_stride.value(0)), 0);
 
diff --git a/tests/test_layout_padded_right.cpp b/tests/test_layout_padded_right.cpp
index 2a600e28..d5e8300c 100644
--- a/tests/test_layout_padded_right.cpp
+++ b/tests/test_layout_padded_right.cpp
@@ -304,6 +304,8 @@ TEST(LayoutrightTests, construction)
   ASSERT_EQ((KokkosEx::layout_right_padded<Kokkos::dynamic_extent>::mapping<Kokkos::extents<std::size_t, 3>>(KokkosEx::layout_right_padded<4>::mapping<Kokkos::extents<std::size_t, 3>>()).padded_stride.value(0)), 0);
   ASSERT_EQ((KokkosEx::layout_right_padded<Kokkos::dynamic_extent>::mapping<Kokkos::extents<std::size_t, 7, 5>>(KokkosEx::layout_right_padded<4>::mapping<Kokkos::extents<std::size_t, 7, 5>>()).extents()), (Kokkos::extents<std::size_t, 7, 5>()));
   ASSERT_EQ((KokkosEx::layout_right_padded<Kokkos::dynamic_extent>::mapping<Kokkos::extents<std::size_t, 7, 5>>(KokkosEx::layout_right_padded<4>::mapping<Kokkos::extents<std::size_t, 7, 5>>()).padded_stride.value(0)), 8);
+  ASSERT_EQ((KokkosEx::layout_right_padded<Kokkos::dynamic_extent>::mapping<Kokkos::extents<std::size_t, 7, 5>>(KokkosEx::layout_right_padded<4>::mapping<Kokkos::extents<std::size_t, Kokkos::dynamic_extent, 5>>(Kokkos::extents<size_t, Kokkos::dynamic_extent, 5>(7))).extents()), (Kokkos::extents<std::size_t, 7, 5>()));
+  ASSERT_EQ((KokkosEx::layout_right_padded<Kokkos::dynamic_extent>::mapping<Kokkos::extents<std::size_t, 7, 5>>(KokkosEx::layout_right_padded<4>::mapping<Kokkos::extents<std::size_t, Kokkos::dynamic_extent, 5>>(Kokkos::extents<size_t, Kokkos::dynamic_extent, 5>(7))).padded_stride.value(0)), 8);
   ASSERT_EQ((KokkosEx::layout_right_padded<Kokkos::dynamic_extent>::mapping<Kokkos::extents<std::size_t, 7, Kokkos::dynamic_extent>>(KokkosEx::layout_right_padded<4>::mapping<Kokkos::extents<std::size_t, 7, 5>>()).extents()), (Kokkos::extents<std::size_t, 7, 5>()));
   ASSERT_EQ((KokkosEx::layout_right_padded<Kokkos::dynamic_extent>::mapping<Kokkos::extents<std::size_t, 7, Kokkos::dynamic_extent>>(KokkosEx::layout_right_padded<4>::mapping<Kokkos::extents<std::size_t, 7, 5>>()).padded_stride.value(0)), 8);
 
@@ -311,6 +313,8 @@ TEST(LayoutrightTests, construction)
   ASSERT_EQ(KokkosEx::layout_right_padded<4>::mapping<Kokkos::extents<std::size_t>>(KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t>>()).extents(), Kokkos::extents<std::size_t>());
   ASSERT_EQ((KokkosEx::layout_right_padded<4>::mapping<Kokkos::extents<std::size_t, 3>>(KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t, 3>>()).extents()), (Kokkos::extents<std::size_t, 3>()));
   ASSERT_EQ((KokkosEx::layout_right_padded<4>::mapping<Kokkos::extents<std::size_t, 3>>(KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t, 3>>()).padded_stride.value(0)), 0);
+  ASSERT_EQ((KokkosEx::layout_right_padded<4>::mapping<Kokkos::extents<std::size_t, 3>>(KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t, Kokkos::dynamic_extent>>(Kokkos::dextents<size_t, 1>(3))).extents()), (Kokkos::extents<std::size_t, 3>()));
+  ASSERT_EQ((KokkosEx::layout_right_padded<4>::mapping<Kokkos::extents<std::size_t, 3>>(KokkosEx::layout_left_padded<4>::mapping<Kokkos::extents<std::size_t, Kokkos::dynamic_extent>>(Kokkos::dextents<size_t, 1>(3))).padded_stride.value(0)), 0);
   ASSERT_EQ((KokkosEx::layout_right_padded<4>::mapping<Kokkos::extents<std::size_t, 3>>(KokkosEx::layout_left_padded<Kokkos::dynamic_extent>::mapping<Kokkos::extents<std::size_t, 3>>({}, 4)).extents()), (Kokkos::extents<std::size_t, 3>()));
   ASSERT_EQ((KokkosEx::layout_right_padded<4>::mapping<Kokkos::extents<std::size_t, 3>>(KokkosEx::layout_left_padded<Kokkos::dynamic_extent>::mapping<Kokkos::extents<std::size_t, 3>>({}, 4)).padded_stride.value(0)), 0);
 
diff --git a/tests/test_submdspan.cpp b/tests/test_submdspan.cpp
index a0f4e043..184326d8 100644
--- a/tests/test_submdspan.cpp
+++ b/tests/test_submdspan.cpp
@@ -140,6 +140,7 @@ using submdspan_test_types =
     // layout_right to layout_right Check Extents Preservation
     , std::tuple<Kokkos::layout_right, Kokkos::layout_right, Kokkos::extents<size_t,10>,           args_t<10>,          Kokkos::extents<size_t,10>, Kokkos::full_extent_t>
     , std::tuple<Kokkos::layout_right, Kokkos::layout_right, Kokkos::extents<size_t,10>,           args_t<10>,          Kokkos::extents<size_t,dyn>, std::pair<int,int>>
+    , std::tuple<Kokkos::layout_right, Kokkos::layout_right, Kokkos::extents<size_t,10>,           args_t<10>,          Kokkos::extents<size_t,dyn>, std::complex<double>>
     , std::tuple<Kokkos::layout_right, Kokkos::layout_right, Kokkos::extents<size_t,10>,           args_t<10>,          Kokkos::extents<size_t>, int>
     , std::tuple<Kokkos::layout_right, Kokkos::layout_right, Kokkos::extents<size_t,10,20>,        args_t<10,20>,       Kokkos::extents<size_t,10,20>, Kokkos::full_extent_t, Kokkos::full_extent_t>
     , std::tuple<Kokkos::layout_right, Kokkos::layout_right, Kokkos::extents<size_t,10,20>,        args_t<10,20>,       Kokkos::extents<size_t,dyn,20>, std::pair<int,int>, Kokkos::full_extent_t>
@@ -274,6 +275,10 @@ struct TestSubMDSpan<
     return std::pair<int,int>(1,3);
   }
   MDSPAN_INLINE_FUNCTION
+  static auto create_slice_arg(std::complex<double>) {
+    return std::complex<double>{1.,3.};
+  }
+  MDSPAN_INLINE_FUNCTION
   static auto create_slice_arg(Kokkos::strided_slice<int,int,int>) {
     return Kokkos::strided_slice<int,int,int>{1,3,2};
   }
@@ -300,6 +305,12 @@ struct TestSubMDSpan<
   }
   template<class SrcMDSpan, class SubMDSpan, size_t ... SrcIdx, size_t ... SubIdx, class ... SliceArgs>
   MDSPAN_INLINE_FUNCTION
+  static bool check_submdspan_match(int src_idx, int sub_idx, SrcMDSpan src_mds, SubMDSpan sub_mds, std::index_sequence<SrcIdx...>, std::index_sequence<SubIdx...>, std::complex<double> p, SliceArgs ... slices) {
+    using idx_t = typename SubMDSpan::index_type;
+    return (sub_mds.extent(sub_idx)==static_cast<idx_t>(p.imag()-p.real())) && check_submdspan_match(++src_idx, ++sub_idx, src_mds, sub_mds, std::index_sequence<SrcIdx...,2>(), std::index_sequence<SubIdx...,1>(), slices...);
+  }
+  template<class SrcMDSpan, class SubMDSpan, size_t ... SrcIdx, size_t ... SubIdx, class ... SliceArgs>
+  MDSPAN_INLINE_FUNCTION
   static bool check_submdspan_match(int src_idx, int sub_idx, SrcMDSpan src_mds, SubMDSpan sub_mds, std::index_sequence<SrcIdx...>, std::index_sequence<SubIdx...>,
                                      Kokkos::strided_slice<int,int,int> p, SliceArgs ... slices) {
     using idx_t = typename SubMDSpan::index_type;