CountedPtrOrPtr.h

 
#pragma once

 
#if defined(CountedPtrOrPtr_RECURSES)
#error Recursive header files inclusion detected in CountedPtrOrPtr.h
#else // defined(CountedPtrOrPtr_RECURSES)
#define CountedPtrOrPtr_RECURSES
 
#if !defined CountedPtrOrPtr_h
#define CountedPtrOrPtr_h

// Inclusions
#include <iostream>
#include "DGtal/base/Common.h"
#include "DGtal/base/CountedPtr.h"
 
namespace DGtal
{
  template <typename T> class CountedConstPtrOrConstPtr;

  // template class CountedPtrOrPtr
  template <typename T>
  class CountedPtrOrPtr
  {
  public:
    friend class CountedConstPtrOrConstPtr<T>;
 
    // ----------------------- Standard services ------------------------------
  public:

    typedef typename CountedPtr<T>::Counter Counter;

    inline explicit CountedPtrOrPtr( T* p = 0, bool isCountedPtr = true )
      : myAny(0), myIsCountedPtr( isCountedPtr )
    {
      if ( isCountedPtr ) {
        if (p) myAny = static_cast<void*>( new Counter( p ) );
      }
      else
        myAny = static_cast<void*>( p );
    }

    ~CountedPtrOrPtr()
    {
      if ( myIsCountedPtr ) release();
    }

    CountedPtrOrPtr( const CountedPtr<T> & r ) noexcept
      : myIsCountedPtr( true )
    {
      acquire( r.myCounter );
    }

    CountedPtrOrPtr(const CountedPtrOrPtr& r) noexcept
      : myIsCountedPtr( r.myIsCountedPtr )
    {
      if ( myIsCountedPtr )
        acquire( r.counterPtr() );
      else
        myAny = r.myAny;
    }

    CountedPtrOrPtr& operator=(const CountedPtrOrPtr& r)
    {
      if ( this != & r ) {
        if ( myIsCountedPtr ) release();
        myIsCountedPtr = r.myIsCountedPtr;
        if ( r.myIsCountedPtr ) acquire( r.counterPtr() );
        else myAny = r.myAny;
      }
      return *this;
    }

    CountedPtrOrPtr& operator=(const CountedPtr<T>& r)
    {
      if ( myIsCountedPtr ) release();
      myIsCountedPtr = true;
      acquire( r.myCounter );
      return *this;
    }

    bool isSmart() const
    {
      return myIsCountedPtr;
    }

    bool isSimple() const
    {
      return ! myIsCountedPtr;
    }

    bool operator==( const T* other ) const
    {
      return myIsCountedPtr ? ( myAny ? counterPtr()->ptr : 0 ) == other : ptr() == other;
    }

    bool operator!=( const T* other ) const
    {
      return myIsCountedPtr ? ( myAny ? counterPtr()->ptr : 0 ) != other : ptr() != other;
    }

    T& operator*()  const noexcept
    {
      // Travis is too slow in Debug mode with this ASSERT.
      ASSERT( isValid() );
      return myIsCountedPtr ? ( * counterPtr()->ptr ) : ( * ptr() );
    }

    T* operator->() const noexcept
    {
      // Travis is too slow in Debug mode with this ASSERT.
      ASSERT( isValid() );
      return myIsCountedPtr ? counterPtr()->ptr : ptr();
    }

    T* get()        const noexcept
    {
      return myIsCountedPtr ? ( myAny ? counterPtr()->ptr : 0 ) : ptr();
    }

    bool unique()   const noexcept
    {
      return myIsCountedPtr
        ? ( myAny ? counterPtr()->count == 1 : true )
        : true;
    }

    unsigned int count() const
    {
      return myIsCountedPtr ? counterPtr()->count : 0;
    }

    inline T* drop()
    { // Gives back the pointer without deleting him. Delete only the counter.
      ASSERT( isValid() );
      if ( myIsCountedPtr ) {
        ASSERT( unique() );
        T* tmp = counterPtr()->ptr;
        delete counterPtr();
        myAny = 0;
        return tmp;
      } else {
        return ptr();
      }
    }
 
private:

    void* myAny;
    bool myIsCountedPtr;

    inline Counter* counterPtr() const
    {
      // Travis is too slow in Debug mode with this ASSERT.
      ASSERT( myIsCountedPtr );
      return static_cast<Counter*>( myAny );
    }

    inline T* ptr() const
    {
      // Travis is too slow in Debug mode with this ASSERT.
      ASSERT( ! myIsCountedPtr );
      return static_cast<T*>( myAny );
    }

    inline void acquire(Counter* c) noexcept
    { // increment the count
      // Travis is too slow in Debug mode with this ASSERT.
      ASSERT( myIsCountedPtr );
      myAny = static_cast<void*>( c );
      if (c) ++c->count;
    }

    void release()
    { // decrement the count, delete if it is 0
      // Travis is too slow in Debug mode with this ASSERT.
      ASSERT( myIsCountedPtr );
      if (myAny) {
        Counter * counter = counterPtr();
        if (--counter->count == 0) {
          delete counter->ptr;
          delete counter;
        }
        myAny = 0;
      }
    }
 
 
    // ----------------------- Interface --------------------------------------
  public:

    void selfDisplay ( std::ostream & out ) const;

    bool isValid() const;
 
    // ------------------------- Protected Data ------------------------------
  private:
    // ------------------------- Private Data --------------------------------
  private:
 
    // ------------------------- Hidden services ------------------------------
  protected:
 
 
    // ------------------------- Internals ------------------------------------
  private:
 
  }; // end of class CountedPtrOrPtr
 

  template <typename T>
  std::ostream&
  operator<< ( std::ostream & out, const CountedPtrOrPtr<T> & object );
 
} // namespace DGtal
 

// Includes inline functions.
#include "DGtal/base/CountedPtrOrPtr.ih"
 
//                                                                           //
 
#endif // !defined CountedPtrOrPtr_h
 
#undef CountedPtrOrPtr_RECURSES
#endif // else defined(CountedPtrOrPtr_RECURSES)