Merge pull request #168 from JohanMabille/strides

pystrides_adaptor now holds signed integers

Author: SylvainCorlay

include/xtensor-python/pyarray.hpp

@@ -328,6 +328,7 @@ namespace xt
         using const_reference = typename base_type::const_reference;
         using pointer = typename base_type::pointer;
         using size_type = typename base_type::size_type;
+        using difference_type = typename base_type::difference_type;
         using shape_type = typename base_type::shape_type;
         using strides_type = typename base_type::strides_type;
         using backstrides_type = typename base_type::backstrides_type;
@@ -745,7 +746,7 @@ namespace xt
     {
         m_shape = inner_shape_type(reinterpret_cast<size_type*>(PyArray_SHAPE(this->python_array())),
                                    static_cast<size_type>(PyArray_NDIM(this->python_array())));
-        m_strides = inner_strides_type(reinterpret_cast<size_type*>(PyArray_STRIDES(this->python_array())),
+        m_strides = inner_strides_type(reinterpret_cast<difference_type*>(PyArray_STRIDES(this->python_array())),
                                        static_cast<size_type>(PyArray_NDIM(this->python_array())));
 
         if (L != layout_type::dynamic && !do_strides_match(m_shape, m_strides, L))

include/xtensor-python/pystrides_adaptor.hpp

@@ -27,7 +27,7 @@ namespace xt
     {
     public:
 
-        using value_type = std::size_t;
+        using value_type = std::ptrdiff_t;
         using const_reference = value_type;
         using const_pointer = const value_type*;
         using size_type = std::size_t;

test/test_pyarray.cpp

@@ -11,6 +11,7 @@
 #include "xtensor-python/pyarray.hpp"
 
 #include "xtensor/xarray.hpp"
+#include "xtensor/xview.hpp"
 
 #include "test_common.hpp"
 
@@ -241,4 +242,11 @@ namespace xt
         EXPECT_TRUE(std::equal(sc2.begin(), sc2.end(), a.shape().begin()) && a.shape().size() == 1);
         EXPECT_EQ(ptr, a.data());
     }
+
+    TEST(pyarray, view)
+    {
+        xt::pyarray<int> arr = xt::zeros<int>({ 10 });
+        auto v = xt::view(arr, xt::all());
+        EXPECT_EQ(v(0), 0.);
+    }
 }

test/test_pytensor.cpp

@@ -11,6 +11,7 @@
 #include "xtensor-python/pytensor.hpp"
 
 #include "xtensor/xtensor.hpp"
+#include "xtensor/xview.hpp"
 
 #include "test_common.hpp"
 
@@ -231,4 +232,11 @@ namespace xt
         // and the second element is `0`.
         EXPECT_THROW(a.reshape({6, 5}), std::runtime_error);
     }
+
+    TEST(pytensor, view)
+    {
+        xt::pytensor<int, 1> arr = xt::zeros<int>({ 10 });
+        auto v = xt::view(arr, xt::all());
+        EXPECT_EQ(v(0), 0.);
+    }
 }