[PATCH] where() strikes again...

[Richard Guenther]

Hi!

The nightly tester catched a regression with the WhereProxy again.  This
time I broke the previously working where(true, x) while fixing where(a,
1.0) for dimensions of a greater than one...

So this time a more elaborated fix and a single point of failure for the
still unhandled case of where(const, const).

Tested on the existing where tests on serial ia32 linux, ok to apply?

Richard.


2003Dec31  Richard Guenther <richard.guenther at uni-tuebingen.de>

	* src/Evaluator/WhereProxy.h: introduce traits class to find
	dimensionality and type of the where expression.

Index: Evaluator/WhereProxy.h
===================================================================
RCS file: /home/pooma/Repository/r2/src/Evaluator/WhereProxy.h,v
retrieving revision 1.7
diff -u -u -r1.7 WhereProxy.h
--- Evaluator/WhereProxy.h	30 Dec 2003 16:24:05 -0000	1.7
+++ Evaluator/WhereProxy.h	31 Dec 2003 15:59:29 -0000
@@ -76,6 +76,29 @@
 template<class F, class B>
 struct WhereProxy
 {
+  template <class Cond, class Val, class F1, class B1>
+  struct WhereProxyTraits {
+    enum { dimensions = F1::dimensions };
+    typedef typename ForEach<Val, EvalLeaf<dimensions>, OpCombine>::Type_t Element_t;
+  };
+  template <class Cond, class T, class F1, class B1>
+  struct WhereProxyTraits<Cond, Scalar<T>, F1, B1> {
+    enum { dimensions = F1::dimensions };
+    typedef T Element_t;
+  };
+  template <class Val, class T, class F1, class B1>
+  struct WhereProxyTraits<Scalar<T>, Val, F1, B1> {
+    enum { dimensions = B1::dimensions };
+    typedef typename ForEach<Val, EvalLeaf<dimensions>, OpCombine>::Type_t Element_t;
+  };
+  template <class T1, class T2, class F1, class B1>
+  struct WhereProxyTraits<Scalar<T1>, Scalar<T2>, F1, B1> {
+    // We open a can of worms, if we try to support this strange case.
+    // Just use the simpler
+    // if (cond)
+    //   lhs = val;
+  };
+
   WhereProxy(const F& f, const B& b) : f_m(f), b_m(b) { }

   typedef BinaryNode<WhereMask,
@@ -85,8 +108,8 @@
   typedef typename ExpressionTraits<Tree_t>::Type_t           ETrait_t;
   typedef typename ConvertWhereProxy<ETrait_t,Tree_t>::Make_t MakeFromTree_t;
   typedef typename MakeFromTree_t::Expression_t               WhereMask_t;
-  typedef typename ForEach<typename CreateLeaf<B>::Leaf_t,
-			   EvalLeaf<F::dimensions>, OpCombine>::Type_t Element_t;
+  typedef typename WhereProxyTraits<typename CreateLeaf<F>::Leaf_t,
+	typename CreateLeaf<B>::Leaf_t, F, B>::Element_t      Element_t;

   inline WhereMask_t
   whereMask() const