Smart pointer enhancements, initial commit

[SVN r12439]

include/boost/shared_array.hpp

@@ -0,0 +1,136 @@
+#ifndef BOOST_SHARED_ARRAY_HPP_INCLUDED
+#define BOOST_SHARED_ARRAY_HPP_INCLUDED
+
+//
+//  shared_array.hpp
+//
+//  (C) Copyright Greg Colvin and Beman Dawes 1998, 1999.
+//  Copyright (c) 2001, 2002 Peter Dimov
+//
+//  Permission to copy, use, modify, sell and distribute this software
+//  is granted provided this copyright notice appears in all copies.
+//  This software is provided "as is" without express or implied
+//  warranty, and with no claim as to its suitability for any purpose.
+//
+//  See http://www.boost.org for most recent version including documentation.
+//
+
+#include <boost/config.hpp>   // for broken compiler workarounds
+
+#if defined(BOOST_NO_MEMBER_TEMPLATES) && !defined(BOOST_MSVC6_MEMBER_TEMPLATES)
+#include <boost/detail/shared_array_nmt.hpp>
+#else
+
+#include <boost/assert.hpp>
+#include <boost/checked_delete.hpp>
+
+#include <boost/detail/shared_count.hpp>
+
+#include <cstddef>            // for std::ptrdiff_t
+#include <algorithm>          // for std::swap
+#include <functional>         // for std::less
+
+namespace boost
+{
+
+//
+//  shared_array
+//
+//  shared_array extends shared_ptr to arrays.
+//  The array pointed to is deleted when the last shared_array pointing to it
+//  is destroyed or reset.
+//
+
+template<typename T> class shared_array
+{
+private:
+
+    // Borland 5.5.1 specific workarounds
+    typedef checked_array_deleter<T> deleter;
+    typedef shared_array<T> this_type;
+
+public:
+
+    typedef T element_type;
+
+    explicit shared_array(T * p = 0): px(p), pn(p, deleter())
+    {
+    }
+
+    //
+    // Requirements: D's copy constructor must not throw
+    //
+    // shared_array will release p by calling d(p)
+    //
+
+    template<typename D> shared_array(T * p, D d): px(p), pn(p, d)
+    {
+    }
+
+//  generated copy constructor, assignment, destructor are fine
+
+    void reset(T * p = 0)
+    {
+        this_type(p).swap(*this);
+    }
+
+    T & operator[] (std::ptrdiff_t i) const // never throws
+    {
+        BOOST_ASSERT(px != 0);
+        BOOST_ASSERT(i >= 0);
+        return px[i];
+    }
+    
+    T * get() const // never throws
+    {
+        return px;
+    }
+
+    long use_count() const // never throws
+    {
+        return pn.use_count();
+    }
+
+    bool unique() const // never throws
+    {
+        return pn.unique();
+    }
+
+    void swap(shared_array<T> & other) // never throws
+    {
+        std::swap(px, other.px);
+        pn.swap(other.pn);
+    }
+
+private:
+
+    T * px;                     // contained pointer
+    detail::shared_count pn;    // reference counter
+
+};  // shared_array
+
+template<class T, class U> inline bool operator==(shared_array<T> const & a, shared_array<U> const & b)
+{
+    return a.get() == b.get();
+}
+
+template<class T, class U> inline bool operator!=(shared_array<T> const & a, shared_array<U> const & b)
+{
+    return a.get() != b.get();
+}
+
+template<class T> inline bool operator<(shared_array<T> const & a, shared_array<T> const & b)
+{
+    return std::less<T*>()(a.get(), b.get());
+}
+
+template<class T> void swap(shared_array<T> & a, shared_array<T> & b)
+{
+    a.swap(b);
+}
+
+} // namespace boost
+
+#endif  // #if defined(BOOST_NO_MEMBER_TEMPLATES) && !defined(BOOST_MSVC_MEMBER_TEMPLATES)
+
+#endif  // #ifndef BOOST_SHARED_ARRAY_HPP_INCLUDED