Restrict cast SIMD to floating-point batches

Author: wolfv

include/xtensor/core/xoperation.hpp

@@ -159,7 +159,10 @@ namespace xt
 
                 template <
                     class B,
-                    std::enable_if_t<std::is_same<R, typename xt_simd::revert_simd_traits<B>::type>::value, int> = 0>
+                    std::enable_if_t<
+                        std::is_floating_point<R>::value
+                            && std::is_same<R, typename xt_simd::revert_simd_traits<B>::type>::value,
+                        int> = 0>
                 constexpr B simd_apply(const B& arg) const
                 {
                     return arg;