Remove fallback implementation for AlignmentOf

Since fda5a9e0 AlignmentOf always uses
std::alignment_of and the fallback implementation is no longer used.

dune/common/alignment.hh

@@ -3,7 +3,6 @@
 #ifndef DUNE_ALIGNMENT_HH
 #define DUNE_ALIGNMENT_HH
 
-#include <cstddef>
 #include <type_traits>
 
 namespace Dune
@@ -20,69 +19,6 @@ namespace Dune
    * @author Markus Blatt
    */
 
-  namespace
-  {
-
-    /**
-     * @brief Helper class to measure alignment requirement.
-     * @tparam T The type we want to measure the alignment requirement for.
-     */
-    template<class T>
-    struct AlignmentStruct
-    {
-      char c;
-      T t;
-      void hack();
-    };
-
-    /**
-     * @brief Helper class to measure alignment requirement.
-     * @tparam T The type we want to measure the alignment requirement for.
-     */
-    template<class T, std::size_t N>
-    struct AlignmentHelper
-    {
-      enum { N2 = sizeof(AlignmentStruct<T>) - sizeof(T) - N };
-      char padding1[N];
-      T t;
-      char padding2[N2];
-    };
-
-#define ALIGNMENT_MODULO(a, b)   (a % b == 0 ? \
-                                  static_cast<std::size_t>(b) : \
-                                  static_cast<std::size_t>(a % b))
-#define ALIGNMENT_MIN(a, b)      (static_cast<std::size_t>(a) <   \
-                                  static_cast<std::size_t>(b) ? \
-                                  static_cast<std::size_t>(a) : \
-                                  static_cast<std::size_t>(b))
-    /**  @brief does the actual calculations. */
-    template <class T, std::size_t N>
-    struct AlignmentTester
-    {
-      typedef AlignmentStruct<T>        s;
-      typedef AlignmentHelper<T, N>     h;
-      typedef AlignmentTester<T, N - 1> next;
-      enum
-      {
-        a1       = ALIGNMENT_MODULO(N        , sizeof(T)),
-        a2       = ALIGNMENT_MODULO(h::N2    , sizeof(T)),
-        a3       = ALIGNMENT_MODULO(sizeof(h), sizeof(T)),
-        a        = sizeof(h) == sizeof(s) ? ALIGNMENT_MIN(a1, a2) : a3,
-        result   = ALIGNMENT_MIN(a, next::result)
-      };
-    };
-
-    /**  @brief does the actual calculations. */
-    template <class T>
-    struct AlignmentTester<T, 0>
-    {
-      enum
-      {
-        result = ALIGNMENT_MODULO(sizeof(AlignmentStruct<T>), sizeof(T))
-      };
-    };
-  } //end anonymous namespace
-
   /**
    * @brief Calculates the alignment requirement of a type.
    *