Added support for default constructed multi_arrays:

- default public constructor for multi_array
- default protected constructors for multi_array_ref and const_multi_*
- fixed a bug in index_range regarding degenerate dimiensions.
- Added tests to resize.cpp and constructors.cpp.


[SVN r18111]

include/boost/multi_array/index_range.hpp

@@ -53,7 +53,7 @@ namespace multi_array {
 
     explicit index_range(index start, index finish, index stride=1)
       : start_(start), finish_(finish), stride_(stride),
-        degenerate_(start_ == finish_)
+        degenerate_(false)
     { }
 
 

include/boost/multi_array/multi_array_ref.hpp

@@ -296,6 +296,17 @@ public:
     return !(*this < rhs);
   }
 
+protected:
+  // This is only supplied to support multi_array's default constructor
+  explicit const_multi_array_ref(TPtr base) :
+    base_(base), storage_(c_storage_order()) {
+    index_base_list_.assign(0);
+    boost::array<size_type,NumDims> filler;
+    filler.assign(0);
+    init_multi_array_ref(filler.begin());
+  }
+
+
 // This ensures that const_multi_array_ref types with different TPtr 
 // types can convert to each other
 #ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS
@@ -366,8 +377,9 @@ private:
     // Calculate the array size
     num_elements_ = std::accumulate(extent_list_.begin(),extent_list_.end(),
                             1,std::multiplies<index>());
+#if 0
     assert(num_elements_ != 0);
-
+#endif
     this->compute_strides(stride_list_,extent_list_,storage_);
 
     origin_offset_ =
@@ -588,6 +600,14 @@ public:
   const_reverse_iterator rend() const {
     return super_type::rend();
   }
+
+protected:
+  // This is only supplied to support multi_array's default constructor
+  explicit multi_array_ref(T* base) :
+    super_type(base) {
+  }
+
+
 };
 
 } // namespace boost

include/boost/multi_array/view.hpp

@@ -232,7 +232,9 @@ public: // should be protected
     // Calculate the array size
     num_elements_ = std::accumulate(extent_list_.begin(),extent_list_.end(),
                             size_type(1),std::multiplies<size_type>());
+#if 0
     assert(num_elements_ != 0);
+#endif
   }
 
   typedef boost::array<size_type,NumDims> size_list;

test/constructors.cpp

@@ -52,6 +52,11 @@ test_main(int, char*[])
   int strides[] = { 9, 3, 1 };
   size_type num_elements = 27;
 
+  // Default multi_array constructor
+  {
+    boost::multi_array<double, 3> A;
+  }
+
   // Constructor 1, default storage order and allocator
   {
     boost::multi_array<double, 3> A(sizes);

test/resize.cpp

@@ -66,4 +66,10 @@ int main() {
 
   assert(std::equal(A_resize,A_resize+(4*3*2),A.data()));
 
+
+  {
+    marray defaultA;
+    defaultA.resize(boost::extents[2][3][4]);
+    assert(std::accumulate(defaultA.data(),defaultA.data()+(2*3*4),0) == 0);
+  }
 }