Inverse dependency between xsimd_power and xsimd_scalar

It's good to have xsimd_scalar as standalone as possible.

Author: serge-sans-paille

include/xsimd/math/xsimd_power.hpp

@@ -19,6 +19,8 @@
 #include "xsimd_logarithm.hpp"
 #include "xsimd_numerical_constant.hpp"
 
+#include "xsimd/math/xsimd_scalar.hpp"
+
 namespace xsimd
 {
 
@@ -85,30 +87,6 @@ namespace xsimd
             }
         };
 
-      template <class T0, class T1>
-      inline T0
-      ipow(const T0& t0, const T1& t1)
-      {
-          static_assert(std::is_integral<T1>::value, "second argument must be an integer");
-          T0 a = t0;
-          T1 b = t1;
-          bool const recip = b < 0;
-          T0 r{static_cast<T0>(1)};
-          while (1)
-          {
-              if (b & 1)
-              {
-                  r *= a;
-              }
-              b /= 2;
-              if (b == 0)
-              {
-                  break;
-              }
-              a *= a;
-          }
-          return recip ? 1 / r : r;
-      }
     }
 
     template <class B>

include/xsimd/math/xsimd_scalar.hpp

@@ -207,11 +207,38 @@ namespace xsimd
     }
 #endif
 
+    namespace detail {
+      template <class T0, class T1>
+      inline T0
+      ipow(const T0& t0, const T1& t1)
+      {
+          static_assert(std::is_integral<T1>::value, "second argument must be an integer");
+          T0 a = t0;
+          T1 b = t1;
+          bool const recip = b < 0;
+          T0 r{static_cast<T0>(1)};
+          while (1)
+          {
+              if (b & 1)
+              {
+                  r *= a;
+              }
+              b /= 2;
+              if (b == 0)
+              {
+                  break;
+              }
+              a *= a;
+          }
+          return recip ? 1 / r : r;
+      }
+    }
+
     template <class T0, class T1>
     inline typename std::enable_if<std::is_integral<T1>::value, T0>::type
     pow(const T0& t0, const T1& t1)
     {
-      return detail::ipow(t0, t1);
+        return detail::ipow(t0, t1);
     }
 
     template <class T0, class T1>
@@ -226,7 +253,7 @@ namespace xsimd
     inline typename std::enable_if<std::is_integral<T1>::value, std::complex<T0>>::type
     pow(const std::complex<T0>& t0, const T1& t1)
     {
-      return detail::ipow(t0, t1);
+        return detail::ipow(t0, t1);
     }
 
     template <class T0, class T1>