Extend scoped_ptr to be closer to unique_ptr. Support custom deleters, and deleting arrays.

This is based on the modifications by "Geoffrey Romer"
 <gromer@google.com> to Google's internal version of scoped_ptr<>.  All cleaver tricks are his, not mine. :)

It brings most of the features of C++11's unique_ptr<> into this class and should eliminate the need for scoped_array<>, scoped_malloc_free<>, and possibly a few other scopers.  Please refer to the unique_ptr<> API for documentation.

Divergence from unique_ptr<>:
1) DefaultDeleter<T[n]> (sized-arrays) is explicitly disabled because this construct would cause the single-object delete to be called on a pointer to a T[n]. It is impossible to construct a single-object new expression that returns a T[n]*. You can only get this with new[] which should correspond to DefaultDeleter<T[n][]>. This issue has been raised with the C++ LWG as it is possible a unique_ptr<> spec defect.

2) Reference types for Deleters are not supported. This simplifies implementation significantly because there is no need to distinguish between the converting constructor + converting assignment operator and their move constructor + move assignment operator.

4) Move-only Deleters are not supported. Avoids the need to emulate std::forward().

BUG=109874
TBR=dhollowa,kinuko,ananta,hans,scherkus

Review URL: https://codereview.chromium.org/11149006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@174057 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 6 insertions, 6 deletions

diff --git a/base/callback_internal.h b/base/callback_internal.h
index 2f834c3..d9aba39 100644
--- a/base/callback_internal.h
+++ b/base/callback_internal.h
@@ -130,10 +130,10 @@ struct CallbackParamTraits<T[]> {
 // TODO(ajwong): We might be able to use SFINAE to search for the existence of
 // a Pass() function in the type and avoid the whitelist in CallbackParamTraits
 // and CallbackForward.
-template <typename T>
-struct CallbackParamTraits<scoped_ptr<T> > {
-  typedef scoped_ptr<T> ForwardType;
-  typedef scoped_ptr<T> StorageType;
+template <typename T, typename D>
+struct CallbackParamTraits<scoped_ptr<T, D> > {
+  typedef scoped_ptr<T, D> ForwardType;
+  typedef scoped_ptr<T, D> StorageType;
 };
 
 template <typename T>
@@ -173,8 +173,8 @@ struct CallbackParamTraits<ScopedVector<T> > {
 template <typename T>
 T& CallbackForward(T& t) { return t; }
 
-template <typename T>
-scoped_ptr<T> CallbackForward(scoped_ptr<T>& p) { return p.Pass(); }
+template <typename T, typename D>
+scoped_ptr<T, D> CallbackForward(scoped_ptr<T, D>& p) { return p.Pass(); }
 
 template <typename T>
 scoped_array<T> CallbackForward(scoped_array<T>& p) { return p.Pass(); }