Changeset 529 for library/bdm/shared_ptr.h

Timestamp:

08/14/09 09:03:02 (15 years ago)

Author:

vbarta

Message:

defined *_ptr wrappers of shared pointers

Files:

• library/bdm/shared_ptr.h (modified) (5 diffs)

library/bdm/shared_ptr.h

@@ -1 +1 @@
 /*!
   \file
-  \brief BDM's own smart pointer.
+  \brief BDM's own smart pointers.
   \author Vaclav Barta.
 
@@ -22 +22 @@
 namespace bdm {
 
-//! A naive implementation of roughly a subset of the std::tr1:shared_ptr spec (really just roughly - it ignores memory exceptions, for example; also note I didn't read the spec).
-// The standard template would naturally be preferable, _if_ it was
-// included in the standard libraries of all supported compilers - but
-// that's exactly what remains to be seen...
+/*! \brief A naive implementation of roughly a subset of the std::tr1:shared_ptr spec
+
+  Really just roughly - it ignores memory
+  exceptions, for example; also note I didn't read the spec.
+
+  The standard template would naturally be preferable, _if_ it was
+  included in the standard libraries of all supported compilers - but
+  as of 2009, that's still a problem...
+*/
 template <typename T>
 class shared_ptr {
@@ -41 +46 @@
         }
 
-        //! Constructs a shared_ptr that owns the pointer p (unless p is
-        //! null, in which case this constructor creates an empty
-        //! shared_ptr).
+        /*! 
+          Constructs a shared_ptr that owns the pointer p (unless p
+          is NULL, in which case this constructor creates an empty
+          shared_ptr). When p isn't null, it must have been alllocated
+          by new!
+        */
         shared_ptr ( T *p ) :
                         payload ( p ),
@@ -70 +78 @@
         }
 
-        shared_ptr &operator= ( const shared_ptr &other ) {
+        shared_ptr<T> &operator= ( const shared_ptr<T> &other ) {
                 other.add_ref();
                 del_ref();
@@ -178 +186 @@
 }
 
+/*! \brief A wrapper of shared_ptr which is never empty.
+
+  T must have a default constructor.
+
+  Note that shared_ptr's destructor isn't virtual - don't call delete
+  on pointers to instances of this class.
+ */
+template <typename T>
+class object_ptr : public shared_ptr<T>
+{
+public:
+        /*!
+          \brief Default constructor
+
+          Calls T's default constructor.
+        */
+        object_ptr() : shared_ptr<T> ( new T() ) { }
+
+        /*!
+          \brief Upcast from shared_ptr<T> to object_ptr<T>
+
+          \param b The shared pointer, which must not be empty.
+        */
+        object_ptr ( const shared_ptr<T> &b ) : shared_ptr<T> ( b ) {
+                it_assert_debug ( this->get(), "object_ptr cannot be empty" );
+        }
+
+        /*! 
+          Constructs an object_ptr that owns the pointer p. p must
+          have been alllocated by new!
+        */
+        object_ptr ( T *p ) : shared_ptr<T> ( p ) {
+                it_assert_debug ( p, "object_ptr cannot be empty" );
+        }
+
+        object_ptr<T> &operator= ( const object_ptr<T> &other ) {
+                shared_ptr<T>::operator= ( other );
+                return *this;
+        }
+};
+
+#define SHAREDPTR(class_name) typedef bdm::object_ptr< class_name > class_name##_ptr
+
+#define SHAREDPTR2(template_class_name, template_parameter_name) typedef bdm::object_ptr< template_class_name < template_parameter_name > > template_class_name##_##template_parameter_name##_ptr
+
 }