[SYCL] Fix narrowing type conversion in marray (#7372)

On Windows with -Wc++-narrowing (enabled by default) known-identity test
fails because initializer list has limitations and doesn't allow
narrowing conversions. It may occur when e.g. we use operator~ which
upgrades type. In this case check EnableIfSuitableTypes succeeds but
initializer list limitations may cause compilation errors. Inserting
static_cast is valid since we already have a check for allowed types.

Signed-off-by: Tikhomirova, Kseniya <[email protected]>

Author: KseniyaTikhomirova

sycl/include/sycl/marray.hpp

@@ -64,7 +64,7 @@ template <typename Type, std::size_t NumElements> class marray {
   template <
       typename... ArgTN, typename = EnableIfSuitableTypes<ArgTN...>,
       typename = typename std::enable_if<sizeof...(ArgTN) == NumElements>::type>
-  constexpr marray(const ArgTN &...Args) : MData{Args...} {}
+  constexpr marray(const ArgTN &...Args) : MData{static_cast<Type>(Args)...} {}
 
   constexpr marray(const marray<Type, NumElements> &Rhs) = default;
 

sycl/test/basic_tests/known_identity.cpp

@@ -246,7 +246,7 @@ typename std::enable_if<!std::is_same_v<T, half> && !std::is_same_v<T, float> &&
 checkMarrayKnownIdentity() {
   constexpr marray<T, Num> zeros(T(0));
   constexpr marray<T, Num> ones(T(1));
-  constexpr marray<T, Num> bit_ones(T(~0));
+  constexpr marray<T, Num> bit_ones(~T(0));
 
   static_assert(has_known_identity<plus<>, marray<T, Num>>::value);
   static_assert(