From cc80743d5b81044b7692064647756632a8a712b8 Mon Sep 17 00:00:00 2001
From: Gabriel Mitterrutzner <Gabriel.Mitterrutzner@student.uibk.ac.at>
Date: Mon, 27 Jan 2025 18:06:39 +0100
Subject: [PATCH 1/2] Fix vec constructors

---
 include/simsycl/sycl/vec.hh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/simsycl/sycl/vec.hh b/include/simsycl/sycl/vec.hh
index cdc5718..a5ead20 100644
--- a/include/simsycl/sycl/vec.hh
+++ b/include/simsycl/sycl/vec.hh
@@ -515,7 +515,7 @@ class alignas(detail::vec_alignment_v<DataT, NumElements>) vec {
 
     vec() = default;
 
-    explicit constexpr vec(const DataT &arg) {
+    explicit(num_elements > 1) constexpr vec(const DataT &arg) {
         for(int i = 0; i < NumElements; ++i) { m_elems[i] = arg; }
     }
 

From bf7fe2a5323476c5d80cf8e939d2294cce8cf82f Mon Sep 17 00:00:00 2001
From: Gabriel Mitterrutzner <Gabriel.Mitterrutzner@student.uibk.ac.at>
Date: Mon, 27 Jan 2025 18:24:50 +0100
Subject: [PATCH 2/2] Add explicit conversion to vec

---
 include/simsycl/sycl/vec.hh | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/include/simsycl/sycl/vec.hh b/include/simsycl/sycl/vec.hh
index a5ead20..d029b0a 100644
--- a/include/simsycl/sycl/vec.hh
+++ b/include/simsycl/sycl/vec.hh
@@ -69,6 +69,11 @@ template<typename T, typename DataT, int NumElements>
 concept VecCompatible
     = vec_like_num_elements<DataT, T>::value == 1 || vec_like_num_elements<DataT, T>::value == NumElements;
 
+template<typename From, typename To>
+concept implicitly_convertible = requires { std::is_convertible_v<From, To>; };
+
+template<typename From, typename To>
+concept explicitly_convertible = requires { static_cast<To>(std::declval<From>()); };
 
 template<int... Is>
 struct no_repeat_indices;
@@ -261,6 +266,13 @@ class swizzled_vec {
         return m_elems[indices[0]];
     }
 
+    template<typename T>
+    explicit operator T() const
+        requires(num_elements == 1 && detail::explicitly_convertible<value_type, T>)
+    {
+        return m_elems[indices[0]];
+    }
+
     static constexpr size_t byte_size() noexcept { return sycl::vec<value_type, num_elements>::byte_size(); }
 
     static constexpr size_t size() noexcept { return num_elements; }
@@ -548,6 +560,13 @@ class alignas(detail::vec_alignment_v<DataT, NumElements>) vec {
         return m_elems[0];
     }
 
+    template<typename T>
+    explicit operator T() const
+        requires(NumElements == 1 && detail::explicitly_convertible<DataT, T>)
+    {
+        return m_elems[0];
+    }
+
     static constexpr size_t byte_size() noexcept { return sizeof m_elems; }
 
     static constexpr size_t size() noexcept { return NumElements; }