Add wrapper function to capture pointers

This resolves memory leaks in generated examples.

The function is to be deleted once we finish our API
transition.

examples/meta/generator/targets/cpp.json

@@ -10,9 +10,9 @@
     "Comment": "//$comment\n",
     "Init": {
         "Construct": "auto $name = some<C$type>($arguments)",
-        "Copy": "auto $name = $expr"
+        "Copy": "auto $name = wrap($expr)"
     },
-    "Assign": "$name = $expr",
+    "Assign": "$name = wrap($expr)",
     "Type": {
         "RealFeatures": "DenseFeatures<float64_t>",
         "StringCharFeatures": "CStringFeatures<char>",

src/shogun/base/some.h

@@ -124,6 +124,24 @@ namespace shogun
         return Some<T>::from_raw(ptr);
     }
 
+    template <class T>
+    inline T wrap(const T& value)
+    {
+        return value;
+    }
+
+    template <class T>
+    inline Some<T> wrap(T* ptr)
+    {
+        return Some<T>::from_raw(ptr);
+    }
+
+    template <class T>
+    inline Some<T> wrap(const Some<T>& other)
+    {
+        return other;
+    }
+
 };
 
 #endif /* HAVE_CXX11 */