Use <bit> if possible

Author: onalante-ebay

include/xsimd/types/xsimd_bit.hpp

@@ -5,6 +5,26 @@
 #ifndef XSIMD_BIT_HPP
 #define XSIMD_BIT_HPP
 
+#include <version>
+
+#if __cpp_lib_bitops >= 201907L
+
+#include <bit>
+
+namespace xsimd
+{
+    namespace detail
+    {
+        using std::countl_one;
+        using std::countl_zero;
+        using std::countr_one;
+        using std::countr_zero;
+        using std::popcount;
+    }
+}
+
+#else
+
 #include <climits>
 #include <type_traits>
 
@@ -203,3 +223,4 @@ namespace xsimd
 }
 
 #endif
+#endif