switch NumPy array to object API, avoid unnecessary copy operation in vectorize

include/pybind11/numpy.h

@@ -81,14 +81,13 @@ public:
         if (descr == nullptr)
             throw std::runtime_error("NumPy: unsupported buffer format!");
         Py_intptr_t shape = (Py_intptr_t) size;
-        PyObject *tmp = api.PyArray_NewFromDescr_(
-            api.PyArray_Type_, descr, 1, &shape, nullptr, (void *) ptr, 0, nullptr);
-        if (tmp == nullptr)
+        object tmp = object(api.PyArray_NewFromDescr_(
+            api.PyArray_Type_, descr, 1, &shape, nullptr, (void *) ptr, 0, nullptr), false);
+        if (ptr && tmp)
+            tmp = object(api.PyArray_NewCopy_(tmp.ptr(), -1 /* any order */), false);
+        if (!tmp)
             throw std::runtime_error("NumPy: unable to create array!");
-        m_ptr = api.PyArray_NewCopy_(tmp, -1 /* any order */);
-        Py_DECREF(tmp);
-        if (m_ptr == nullptr)
-            throw std::runtime_error("NumPy: unable to copy array!");
+        m_ptr = tmp.release();
     }
 
     array(const buffer_info &info) {
@@ -102,15 +101,14 @@ public:
         PyObject *descr = api.PyArray_DescrFromType_(fmt);
         if (descr == nullptr)
             throw std::runtime_error("NumPy: unsupported buffer format '" + info.format + "'!");
-        PyObject *tmp = api.PyArray_NewFromDescr_(
+        object tmp(api.PyArray_NewFromDescr_(
             api.PyArray_Type_, descr, info.ndim, (Py_intptr_t *) &info.shape[0],
-            (Py_intptr_t *) &info.strides[0], info.ptr, 0, nullptr);
-        if (tmp == nullptr)
+            (Py_intptr_t *) &info.strides[0], info.ptr, 0, nullptr), false);
+        if (info.ptr && tmp)
+            tmp = object(api.PyArray_NewCopy_(tmp.ptr(), -1 /* any order */), false);
+        if (!tmp)
             throw std::runtime_error("NumPy: unable to create array!");
-        m_ptr = api.PyArray_NewCopy_(tmp, -1 /* any order */);
-        Py_DECREF(tmp);
-        if (m_ptr == nullptr)
-            throw std::runtime_error("NumPy: unable to copy array!");
+        m_ptr = tmp.release();
     }
 
 protected:
@@ -184,25 +182,27 @@ struct vectorize_helper {
         }
 
         /* Check if the parameters are actually compatible */
-        for (size_t i=0; i<N; ++i) {
+        for (size_t i=0; i<N; ++i)
             if (buffers[i].count != 1 && (buffers[i].ndim != ndim || buffers[i].shape != shape))
                 throw std::runtime_error("pybind11::vectorize: incompatible size/dimension of inputs!");
-        }
-
-        /* Call the function */
-        std::vector<Return> result(count);
-        for (size_t i=0; i<count; ++i)
-            result[i] = f((buffers[Index].count == 1
-                               ? *((Args *) buffers[Index].ptr)
-                               :  ((Args *) buffers[Index].ptr)[i])...);
 
         if (count == 1)
-            return cast(result[0]);
+            return cast(f(*((Args *) buffers[Index].ptr)...));
 
-        /* Return the result */
-        return array(buffer_info(result.data(), sizeof(Return),
+        array result(buffer_info(nullptr, sizeof(Return),
             format_descriptor<Return>::value(),
             ndim, shape, strides));
+
+        buffer_info buf = result.request();
+        Return *output = (Return *) buf.ptr;
+
+        /* Call the function */
+        for (size_t i=0; i<count; ++i)
+            output[i] = f((buffers[Index].count == 1
+                               ? *((Args *) buffers[Index].ptr)
+                               : ((Args *) buffers[Index].ptr)[i])...);
+
+        return result;
     }
 };