wtf/OwnArrayPtr.h

   1 /*
   2  *  Copyright (C) 2006 Apple Computer, Inc.
   3  *
   4  *  This library is free software; you can redistribute it and/or
   5  *  modify it under the terms of the GNU Library General Public
   6  *  License as published by the Free Software Foundation; either
   7  *  version 2 of the License, or (at your option) any later version.
   8  *
   9  *  This library is distributed in the hope that it will be useful,
  10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  *  Library General Public License for more details.
  13  *
  14  *  You should have received a copy of the GNU Library General Public License
  15  *  along with this library; see the file COPYING.LIB.  If not, write to
  16  *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  17  *  Boston, MA 02110-1301, USA.
  18  *
  19  */
  20
  21 #ifndef WTF_OwnArrayPtr_h
  22 #define WTF_OwnArrayPtr_h
  23
  24 #include <algorithm>
  25 #include <wtf/Assertions.h>
  26 #include <wtf/Noncopyable.h>
  27
  28 namespace WTF {
  29
  30     template <typename T> class OwnArrayPtr : public Noncopyable {
  31     public:
  32         explicit OwnArrayPtr(T* ptr = 0) : m_ptr(ptr) { }
  33         ~OwnArrayPtr() { safeDelete(); }
  34
  35         T* get() const { return m_ptr; }
  36         T* release() { T* ptr = m_ptr; m_ptr = 0; return ptr; }
  37
  38         void set(T* ptr) { ASSERT(m_ptr != ptr); safeDelete(); m_ptr = ptr; }
  39         void clear() { safeDelete(); m_ptr = 0; }
  40
  41         T& operator*() const { ASSERT(m_ptr); return *m_ptr; }
  42         T* operator->() const { ASSERT(m_ptr); return m_ptr; }
  43
  44         T& operator[](std::ptrdiff_t i) const { ASSERT(m_ptr); ASSERT(i >= 0); return m_ptr[i]; }
  45
  46         bool operator!() const { return !m_ptr; }
  47
  48         // This conversion operator allows implicit conversion to bool but not to other integer types.
  49 #if COMPILER(WINSCW)
  50         operator bool() const { return m_ptr; }
  51 #else
  52         typedef T* OwnArrayPtr::*UnspecifiedBoolType;
  53         operator UnspecifiedBoolType() const { return m_ptr ? &OwnArrayPtr::m_ptr : 0; }
  54 #endif
  55
  56         void swap(OwnArrayPtr& o) { std::swap(m_ptr, o.m_ptr); }
  57
  58     private:
  59         void safeDelete() { typedef char known[sizeof(T) ? 1 : -1]; if (sizeof(known)) delete [] m_ptr; }
  60
  61         T* m_ptr;
  62     };
  63
  64     template <typename T> inline void swap(OwnArrayPtr<T>& a, OwnArrayPtr<T>& b) { a.swap(b); }
  65
  66     template <typename T> inline T* getPtr(const OwnArrayPtr<T>& p)
  67     {
  68         return p.get();
  69     }
  70
  71 } // namespace WTF
  72
  73 using WTF::OwnArrayPtr;
  74
  75 #endif // WTF_OwnArrayPtr_h