--- /dev/null
+/* -*- C++ -*- ------------------------------------------------------------
+
+Copyright (c) 2007 Jesse Anders and Demian Nave http://cmldev.net/
+
+The Configurable Math Library (CML) is distributed under the terms of the
+Boost Software License, v1.0 (see cml/LICENSE for details).
+
+ *-----------------------------------------------------------------------*/
+/** @file
+ * @brief
+ *
+ * Defines promotions between array types.
+ *
+ * @todo Can/should an expression with a fixed-size argument promote to a
+ * fixed array instead of a dynamic array?
+ */
+
+#ifndef array_promotions_h
+#define array_promotions_h
+
+#include <cml/core/cml_meta.h>
+#include <cml/et/scalar_promotions.h>
+
+namespace cml {
+namespace et {
+
+#define VAL_MAX(_a_,_b_) ( ((_a_)>(_b_))?(_a_):(_b_) )
+
+namespace detail {
+
+/* This is specialized for 1D and 2D promotions: */
+template<class A1, class A2, typename DTag1, typename DTag2,
+ typename PromotedSizeTag> struct promote;
+
+/* Promote 1D fixed-size arrays to a 1D fixed-size array: */
+template<class A1, class A2>
+struct promote<A1,A2,oned_tag,oned_tag,fixed_size_tag>
+{
+ typedef typename A1::value_type left_scalar;
+ typedef typename A2::value_type right_scalar;
+
+ /* First, promote the scalar type: */
+ typedef typename ScalarPromote<
+ left_scalar,right_scalar>::type promoted_scalar;
+
+ /* Next, deduce the array size: */
+ enum { Size = VAL_MAX((size_t)A1::array_size, (size_t)A2::array_size) };
+
+ /* Finally, generate the promoted array type: */
+ typedef fixed_1D<promoted_scalar,Size> type;
+};
+
+/* Promote 1D dynamic arrays to a 1D dynamic array: */
+template<class A1, class A2>
+struct promote<A1,A2,oned_tag,oned_tag,dynamic_size_tag>
+{
+ typedef typename A1::value_type left_scalar;
+ typedef typename A2::value_type right_scalar;
+
+ /* First, promote the scalar type: */
+ typedef typename ScalarPromote<
+ left_scalar,right_scalar>::type promoted_scalar;
+
+ /* Next, rebind to get the proper allocator: */
+ typedef typename CML_DEFAULT_ARRAY_ALLOC
+ ::rebind<promoted_scalar>::other allocator;
+
+ /* Finally, generate the promoted array type: */
+ typedef dynamic_1D<promoted_scalar,allocator> type;
+};
+
+/* Promote fixed 2D+1D array expressions to a fixed 1D array: */
+template<class A1, class A2>
+struct promote<A1,A2,twod_tag,oned_tag,fixed_size_tag>
+{
+ typedef typename A1::value_type left_scalar;
+ typedef typename A2::value_type right_scalar;
+
+ /* First, promote the scalar type: */
+ typedef typename ScalarPromote<
+ left_scalar,right_scalar>::type promoted_scalar;
+
+ /* Next, deduce the array size: */
+ enum { Size = (size_t)A1::array_rows };
+
+ /* Finally, generate the promoted array type: */
+ typedef fixed_1D<promoted_scalar,Size> type;
+};
+
+/* Promote fixed 1D+2D array expressions to a fixed 1D array: */
+template<class A1, class A2>
+struct promote<A1,A2,oned_tag,twod_tag,fixed_size_tag>
+{
+ typedef typename A1::value_type left_scalar;
+ typedef typename A2::value_type right_scalar;
+
+ /* First, promote the scalar type: */
+ typedef typename ScalarPromote<
+ left_scalar,right_scalar>::type promoted_scalar;
+
+ /* Next, deduce the array size: */
+ enum { Size = (size_t)A2::array_cols };
+
+ /* Finally, generate the promoted array type: */
+ typedef fixed_1D<promoted_scalar,Size> type;
+};
+
+/* Promote dynamic 2D+1D array expression to a 1D dynamic array: */
+template<class A1, class A2>
+struct promote<A1,A2,twod_tag,oned_tag,dynamic_size_tag>
+{
+ typedef typename A1::value_type left_scalar;
+ typedef typename A2::value_type right_scalar;
+
+ /* First, promote the scalar type: */
+ typedef typename ScalarPromote<
+ left_scalar,right_scalar>::type promoted_scalar;
+
+ /* Next, rebind to get the proper allocator: */
+ typedef typename CML_DEFAULT_ARRAY_ALLOC
+ ::rebind<promoted_scalar>::other allocator;
+
+ /* Finally, generate the promoted array type: */
+ typedef dynamic_1D<promoted_scalar,allocator> type;
+};
+
+/* Promote dynamic 1D+2D array expression to a 1D dynamic array: */
+template<class A1, class A2>
+struct promote<A1,A2,oned_tag,twod_tag,dynamic_size_tag>
+{
+ typedef typename A1::value_type left_scalar;
+ typedef typename A2::value_type right_scalar;
+
+ /* First, promote the scalar type: */
+ typedef typename ScalarPromote<
+ left_scalar,right_scalar>::type promoted_scalar;
+
+ /* Next, rebind to get the proper allocator: */
+ typedef typename CML_DEFAULT_ARRAY_ALLOC
+ ::rebind<promoted_scalar>::other allocator;
+
+ /* Finally, generate the promoted array type: */
+ typedef dynamic_1D<promoted_scalar,allocator> type;
+};
+
+
+/* This is a helper to deduce the result of a promoted 2D array: */
+template<typename LeftL, typename RightL> struct deduce_layout {
+#if defined(CML_ALWAYS_PROMOTE_TO_DEFAULT_LAYOUT)
+ typedef CML_DEFAULT_ARRAY_LAYOUT promoted_layout;
+#else
+ typedef typename select_if<
+ same_type<LeftL,RightL>::is_true, LeftL,
+ CML_DEFAULT_ARRAY_LAYOUT>::result promoted_layout;
+#endif
+};
+
+/* Promote 2D fixed-size arrays to a 2D fixed-size array. The resulting
+ * matrix has the same number of rows as A1, and the same number of
+ * columns as A2.
+ */
+template<class A1, class A2>
+struct promote<A1,A2,twod_tag,twod_tag,fixed_size_tag>
+{
+ typedef typename A1::value_type left_scalar;
+ typedef typename A2::value_type right_scalar;
+
+ /* First, promote the scalar type: */
+ typedef typename ScalarPromote<
+ left_scalar,right_scalar>::type promoted_scalar;
+
+ /* Next, deduce the array size: */
+ enum {
+ Rows = (size_t)A1::array_rows,
+ Cols = (size_t)A2::array_cols
+ };
+
+ /* Then deduce the array layout: */
+ typedef typename A1::layout left_layout;
+ typedef typename A2::layout right_layout;
+ typedef typename deduce_layout<left_layout,right_layout>
+ ::promoted_layout promoted_layout;
+
+ /* Finally, generate the promoted array type: */
+ typedef fixed_2D<promoted_scalar,Rows,Cols,promoted_layout> type;
+};
+
+/* Promote 2D dynamic arrays to a 2D dynamic array: */
+template<class A1, class A2>
+struct promote<A1,A2,twod_tag,twod_tag,dynamic_size_tag>
+{
+ typedef typename A1::value_type left_scalar;
+ typedef typename A2::value_type right_scalar;
+
+ /* First, promote the scalar type: */
+ typedef typename ScalarPromote<
+ left_scalar,right_scalar>::type promoted_scalar;
+
+ /* Next, rebind to get the proper allocator: */
+ typedef typename CML_DEFAULT_ARRAY_ALLOC
+ ::rebind<promoted_scalar>::other allocator;
+
+ /* Then deduce the array layout: */
+ typedef typename A1::layout left_layout;
+ typedef typename A2::layout right_layout;
+ typedef typename deduce_layout<left_layout,right_layout>
+ ::promoted_layout promoted_layout;
+
+ /* Finally, generate the promoted array type: */
+ typedef dynamic_2D<promoted_scalar,promoted_layout,allocator> type;
+};
+
+} // namespace detail
+
+/** Class to promote array types.
+ *
+ * Both arguments must be array types.
+ *
+ * @sa fixed_1D
+ * @sa fixed_2D
+ * @sa dynamic_1D
+ * @sa dynamic_2D
+ */
+template<class A1, class A2>
+struct ArrayPromote
+{
+ /* Shorthand: */
+ //typedef typename A1::value_type left_scalar;
+ //typedef typename A2::value_type right_scalar;
+ typedef typename A1::dimension_tag left_dtag;
+ typedef typename A2::dimension_tag right_dtag;
+
+ /* Deduce the proper type based upon the characteristics of AT1 and
+ * AT2. This is the table of type conversions:
+ *
+ * AT1 AT2 Result
+ * memory size memory size memory size
+ *
+ * fixed fixed fixed fixed fixed fixed
+ * fixed fixed dynamic dynamic dynamic dynamic
+ * fixed fixed external fixed fixed fixed
+ * fixed fixed external dynamic dynamic dynamic
+ *
+ * dynamic dynamic fixed fixed dynamic dynamic
+ * dynamic dynamic dynamic dynamic dynamic dynamic
+ * dynamic dynamic external fixed dynamic dynamic
+ * dynamic dynamic external dynamic dynamic dynamic
+ *
+ * external fixed external fixed fixed fixed
+ * external fixed fixed fixed fixed fixed
+ * external fixed dynamic dynamic dynamic dynamic
+ * external fixed external dynamic dynamic dynamic
+ *
+ * external dynamic external fixed dynamic dynamic
+ * external dynamic fixed fixed dynamic dynamic
+ * external dynamic dynamic dynamic dynamic dynamic
+ * external dynamic external dynamic dynamic dynamic
+ *
+ * Note that if one argument is a dynamically-sized array, the result
+ * must be a dynamically allocated and sized array. Likewise, if both
+ * arguments have fixed size, the result can be a fixed-sized array.
+ */
+
+ /* Check if both arguments are fixed-size arrays. If so, the promoted
+ * array will be a fixed array, and if not, it will be a dynamic array:
+ */
+ typedef typename select_if<
+ (same_type<typename A1::size_tag, fixed_size_tag>::is_true
+ && same_type<typename A2::size_tag, fixed_size_tag>::is_true),
+ fixed_size_tag, /* True */
+ dynamic_size_tag /* False */
+ >::result promoted_size_tag;
+
+ /* Deduce the promoted type: */
+ typedef typename detail::promote<
+ A1, A2, left_dtag, right_dtag, promoted_size_tag>::type type;
+};
+
+/* Cleanup internal macros: */
+#undef VAL_MAX
+
+} // namespace et
+} // namespace cml
+
+#endif
+
+// -------------------------------------------------------------------------
+// vim:ft=cpp
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