wtf/OwnArrayPtr.h

   1 // -*- mode: c++; c-basic-offset: 4 -*-
   2 /*
   3  *  Copyright (C) 2006 Apple Computer, Inc.
   4  *
   5  *  This library is free software; you can redistribute it and/or
   6  *  modify it under the terms of the GNU Library General Public
   7  *  License as published by the Free Software Foundation; either
   8  *  version 2 of the License, or (at your option) any later version.
   9  *
  10  *  This library is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  *  Library General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU Library General Public License
  16  *  along with this library; see the file COPYING.LIB.  If not, write to
  17  *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  18  *  Boston, MA 02110-1301, USA.
  19  *
  20  */
  21
  22 #ifndef WTF_OwnArrayPtr_h
  23 #define WTF_OwnArrayPtr_h
  24
  25 #include <algorithm>
  26 #include <wtf/Assertions.h>
  27 #include <wtf/Noncopyable.h>
  28
  29 namespace WTF {
  30
  31     template <typename T> class OwnArrayPtr : Noncopyable {
  32     public:
  33         explicit OwnArrayPtr(T* ptr = 0) : m_ptr(ptr) { }
  34         ~OwnArrayPtr() { safeDelete(); }
  35
  36         T* get() const { return m_ptr; }
  37         T* release() { T* ptr = m_ptr; m_ptr = 0; return ptr; }
  38
  39         void set(T* ptr) { ASSERT(m_ptr != ptr); safeDelete(); m_ptr = ptr; }
  40         void clear() { safeDelete(); m_ptr = 0; }
  41
  42         T& operator*() const { ASSERT(m_ptr); return *m_ptr; }
  43         T* operator->() const { ASSERT(m_ptr); return m_ptr; }
  44
  45         T& operator[](std::ptrdiff_t i) const { ASSERT(m_ptr); ASSERT(i >= 0); return m_ptr[i]; }
  46
  47         bool operator!() const { return !m_ptr; }
  48
  49         // This conversion operator allows implicit conversion to bool but not to other integer types.
  50         typedef T* OwnArrayPtr::*UnspecifiedBoolType;
  51         operator UnspecifiedBoolType() const { return m_ptr ? &OwnArrayPtr::m_ptr : 0; }
  52
  53         void swap(OwnArrayPtr& o) { std::swap(m_ptr, o.m_ptr); }
  54
  55     private:
  56         void safeDelete() { typedef char known[sizeof(T) ? 1 : -1]; if (sizeof(known)) delete [] m_ptr; }
  57
  58         T* m_ptr;
  59     };
  60
  61     template <typename T> inline void swap(OwnArrayPtr<T>& a, OwnArrayPtr<T>& b) { a.swap(b); }
  62
  63     template <typename T> inline T* getPtr(const OwnArrayPtr<T>& p)
  64     {
  65         return p.get();
  66     }
  67
  68 } // namespace WTF
  69
  70 using WTF::OwnArrayPtr;
  71
  72 #endif // WTF_OwnArrayPtr_h