src/base/scoped_ptr.h - mozc - Git at Google

 // Copyright 2010-2015, Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 // copyright notice, this list of conditions and the following disclaimer
 // in the documentation and/or other materials provided with the
 // distribution.
 //     * Neither the name of Google Inc. nor the names of its
 // contributors may be used to endorse or promote products derived from
 // this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 #ifndef MOZC_BASE_SCOPED_PTR_H_
 #define MOZC_BASE_SCOPED_PTR_H_

 //  This is an implementation designed to match the anticipated future TR2
 //  implementation of the scoped_ptr class, and its closely-related brethren,
 //  scoped_array.
 //
 //  See http://wiki/Main/ScopedPointerInterface for the spec that drove this
 //  file.

 #include <assert.h>
 #include <cstddef>

 #include "base/port.h"

 template <class C> class scoped_ptr;

 // A scoped_ptr<T> is like a T*, except that the destructor of scoped_ptr<T>
 // automatically deletes the pointer it holds (if any).
 // That is, scoped_ptr<T> owns the T object that it points to.
 // Like a T*, a scoped_ptr<T> may hold either NULL or a pointer to a T object.
 // Also like T*, scoped_ptr<T> is thread-compatible, and once you
 // dereference it, you get the threadsafety guarantees of T.
 //
 // The size of a scoped_ptr is small:
 // sizeof(scoped_ptr<C>) == sizeof(C*)
 template <class C>
 class scoped_ptr {
  public:

   // The element type
   typedef C element_type;

   // Constructor.  Defaults to intializing with NULL.
   // There is no way to create an uninitialized scoped_ptr.
   // The input parameter must be allocated with new.
   explicit scoped_ptr(C* p = NULL) : ptr_(p) { }

   // Destructor.  If there is a C object, delete it.
   // We don't need to test ptr_ == NULL because C++ does that for us.
   ~scoped_ptr() {
     enum { type_must_be_complete = sizeof(C) };
     delete ptr_;
   }

   // Reset.  Deletes the current owned object, if any.
   // Then takes ownership of a new object, if given.
   // this->reset(this->get()) works.
   void reset(C* p = NULL) {
     if (p != ptr_) {
       enum { type_must_be_complete = sizeof(C) };
       delete ptr_;
       ptr_ = p;
     }
   }

   // Accessors to get the owned object.
   // operator* and operator-> will assert() if there is no current object.
   C& operator*() const {
     assert(ptr_ != NULL);
     return *ptr_;
   }
   C* operator->() const  {
     assert(ptr_ != NULL);
     return ptr_;
   }
   C* get() const { return ptr_; }

   // Comparison operators.
   // These return whether a scoped_ptr and a raw pointer refer to
   // the same object, not just to two different but equal objects.
   bool operator==(const C* p) const { return ptr_ == p; }
   bool operator!=(const C* p) const { return ptr_ != p; }

   // Swap two scoped pointers.
   void swap(scoped_ptr& p2) {
     C* tmp = ptr_;
     ptr_ = p2.ptr_;
     p2.ptr_ = tmp;
   }

   // Release a pointer.
   // The return value is the current pointer held by this object.
   // If this object holds a NULL pointer, the return value is NULL.
   // After this operation, this object will hold a NULL pointer,
   // and will not own the object any more.
   C* release() {
     C* retVal = ptr_;
     ptr_ = NULL;
     return retVal;
   }

  private:
   C* ptr_;

   // Forbid comparison of scoped_ptr types.  If C2 != C, it totally doesn't
   // make sense, and if C2 == C, it still doesn't make sense because you should
   // never have the same object owned by two different scoped_ptrs.
   template <class C2> bool operator==(scoped_ptr<C2> const& p2) const;
   template <class C2> bool operator!=(scoped_ptr<C2> const& p2) const;

   DISALLOW_COPY_AND_ASSIGN(scoped_ptr);
 };

 // Free functions
 template <class C>
 inline void swap(scoped_ptr<C>& p1, scoped_ptr<C>& p2) {
   p1.swap(p2);
 }

 template <class C>
 inline bool operator==(const C* p1, const scoped_ptr<C>& p2) {
   return p1 == p2.get();
 }

 template <class C>
 inline bool operator==(const C* p1, const scoped_ptr<const C>& p2) {
   return p1 == p2.get();
 }

 template <class C>
 inline bool operator!=(const C* p1, const scoped_ptr<C>& p2) {
   return p1 != p2.get();
 }

 template <class C>
 inline bool operator!=(const C* p1, const scoped_ptr<const C>& p2) {
   return p1 != p2.get();
 }

 // Specialization of scoped_ptr for holding arrays.
 //
 // scoped_ptr<C[]> is like scoped_ptr<C>, except that the caller must allocate
 // with new [] and the destructor deletes objects with delete [].
 //
 // As with scoped_ptr<C>, a scoped_ptr<C[]> either points to an array of objects
 // or is NULL.  A scoped_ptr<C[]> owns the array that it points to.
 // scoped_ptr<C[]> is thread-compatible, and once you index into it, the
 // returned objects have only the threadsafety guarantees of C.
 //
 // Size: sizeof(scoped_ptr<C[]>) == sizeof(C*)
 template <class C>
 class scoped_ptr<C[]> {
  public:
   // The element type
   typedef C element_type;

   // Constructor.  Defaults to intializing with NULL.
   // There is no way to create an uninitialized scoped_ptr.
   // The input parameter must be allocated with new [].
   explicit scoped_ptr(C* p = NULL) : array_(p) { }

   // Destructor.  If there is a C object, delete it.
   // We don't need to test ptr_ == NULL because C++ does that for us.
   ~scoped_ptr() {
     enum { type_must_be_complete = sizeof(C) };
     delete[] array_;
   }

   // Reset.  Deletes the current owned object, if any.
   // Then takes ownership of a new object, if given.
   // this->reset(this->get()) works.
   void reset(C* p = NULL) {
     if (p != array_) {
       enum { type_must_be_complete = sizeof(C) };
       delete[] array_;
       array_ = p;
     }
   }

   // Get one element of the current object.
   // Will assert() if there is no current object, or index i is negative.
   C& operator[](std::ptrdiff_t i) const {
     assert(i >= 0);
     assert(array_ != NULL);
     return array_[i];
   }

   // Get a pointer to the zeroth element of the current object.
   // If there is no current object, return NULL.
   C* get() const {
     return array_;
   }

   // Comparison operators.
   // These return whether a scoped_ptr and a raw pointer refer to
   // the same array, not just to two different but equal arrays.
   bool operator==(const C* p) const { return array_ == p; }
   bool operator!=(const C* p) const { return array_ != p; }

   // Swap two scoped arrays.
   void swap(scoped_ptr& p2) {
     C* tmp = array_;
     array_ = p2.array_;
     p2.array_ = tmp;
   }

   // Release an array.
   // The return value is the current pointer held by this object.
   // If this object holds a NULL pointer, the return value is NULL.
   // After this operation, this object will hold a NULL pointer,
   // and will not own the object any more.
   C* release() {
     C* retVal = array_;
     array_ = NULL;
     return retVal;
   }

  private:
   C* array_;

   // Forbid comparison of different scoped_ptr types.
   template <class C2> bool operator==(scoped_ptr<C2[]> const& p2) const;
   template <class C2> bool operator!=(scoped_ptr<C2[]> const& p2) const;

   DISALLOW_COPY_AND_ASSIGN(scoped_ptr);
 };

 // Free functions
 template <class C>
 inline void swap(scoped_ptr<C[]>& p1, scoped_ptr<C[]>& p2) {
   p1.swap(p2);
 }

 template <class C>
 inline bool operator==(const C* p1, const scoped_ptr<C[]>& p2) {
   return p1 == p2.get();
 }

 template <class C>
 inline bool operator==(const C* p1, const scoped_ptr<const C[]>& p2) {
   return p1 == p2.get();
 }

 template <class C>
 inline bool operator!=(const C* p1, const scoped_ptr<C[]>& p2) {
   return p1 != p2.get();
 }

 template <class C>
 inline bool operator!=(const C* p1, const scoped_ptr<const C[]>& p2) {
   return p1 != p2.get();
 }

 #endif  // MOZC_BASE_SCOPED_PTR_H_
	// Copyright 2010-2015, Google Inc.
	// All rights reserved.
	//
	// Redistribution and use in source and binary forms, with or without
	// modification, are permitted provided that the following conditions are
	// met:
	//
	// * Redistributions of source code must retain the above copyright
	// notice, this list of conditions and the following disclaimer.
	// * Redistributions in binary form must reproduce the above
	// copyright notice, this list of conditions and the following disclaimer
	// in the documentation and/or other materials provided with the
	// distribution.
	// * Neither the name of Google Inc. nor the names of its
	// contributors may be used to endorse or promote products derived from
	// this software without specific prior written permission.
	//
	// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

	#ifndef MOZC_BASE_SCOPED_PTR_H_
	#define MOZC_BASE_SCOPED_PTR_H_

	// This is an implementation designed to match the anticipated future TR2
	// implementation of the scoped_ptr class, and its closely-related brethren,
	// scoped_array.
	//
	// See http://wiki/Main/ScopedPointerInterface for the spec that drove this
	// file.

	#include <assert.h>
	#include <cstddef>

	#include "base/port.h"

	template <class C> class scoped_ptr;

	// A scoped_ptr<T> is like a T*, except that the destructor of scoped_ptr<T>
	// automatically deletes the pointer it holds (if any).
	// That is, scoped_ptr<T> owns the T object that it points to.
	// Like a T*, a scoped_ptr<T> may hold either NULL or a pointer to a T object.
	// Also like T*, scoped_ptr<T> is thread-compatible, and once you
	// dereference it, you get the threadsafety guarantees of T.
	//
	// The size of a scoped_ptr is small:
	// sizeof(scoped_ptr<C>) == sizeof(C*)
	template <class C>
	class scoped_ptr {
	public:

	// The element type
	typedef C element_type;

	// Constructor. Defaults to intializing with NULL.
	// There is no way to create an uninitialized scoped_ptr.
	// The input parameter must be allocated with new.
	explicit scoped_ptr(C* p = NULL) : ptr_(p) { }

	// Destructor. If there is a C object, delete it.
	// We don't need to test ptr_ == NULL because C++ does that for us.
	~scoped_ptr() {
	enum { type_must_be_complete = sizeof(C) };
	delete ptr_;
	}

	// Reset. Deletes the current owned object, if any.
	// Then takes ownership of a new object, if given.
	// this->reset(this->get()) works.
	void reset(C* p = NULL) {
	if (p != ptr_) {
	enum { type_must_be_complete = sizeof(C) };
	delete ptr_;
	ptr_ = p;
	}
	}

	// Accessors to get the owned object.
	// operator* and operator-> will assert() if there is no current object.
	C& operator*() const {
	assert(ptr_ != NULL);
	return *ptr_;
	}
	C* operator->() const {
	assert(ptr_ != NULL);
	return ptr_;
	}
	C* get() const { return ptr_; }

	// Comparison operators.
	// These return whether a scoped_ptr and a raw pointer refer to
	// the same object, not just to two different but equal objects.
	bool operator==(const C* p) const { return ptr_ == p; }
	bool operator!=(const C* p) const { return ptr_ != p; }

	// Swap two scoped pointers.
	void swap(scoped_ptr& p2) {
	C* tmp = ptr_;
	ptr_ = p2.ptr_;
	p2.ptr_ = tmp;
	}

	// Release a pointer.
	// The return value is the current pointer held by this object.
	// If this object holds a NULL pointer, the return value is NULL.
	// After this operation, this object will hold a NULL pointer,
	// and will not own the object any more.
	C* release() {
	C* retVal = ptr_;
	ptr_ = NULL;
	return retVal;
	}

	private:
	C* ptr_;

	// Forbid comparison of scoped_ptr types. If C2 != C, it totally doesn't
	// make sense, and if C2 == C, it still doesn't make sense because you should
	// never have the same object owned by two different scoped_ptrs.
	template <class C2> bool operator==(scoped_ptr<C2> const& p2) const;
	template <class C2> bool operator!=(scoped_ptr<C2> const& p2) const;

	DISALLOW_COPY_AND_ASSIGN(scoped_ptr);
	};

	// Free functions
	template <class C>
	inline void swap(scoped_ptr<C>& p1, scoped_ptr<C>& p2) {
	p1.swap(p2);
	}

	template <class C>
	inline bool operator==(const C* p1, const scoped_ptr<C>& p2) {
	return p1 == p2.get();
	}

	template <class C>
	inline bool operator==(const C* p1, const scoped_ptr<const C>& p2) {
	return p1 == p2.get();
	}

	template <class C>
	inline bool operator!=(const C* p1, const scoped_ptr<C>& p2) {
	return p1 != p2.get();
	}

	template <class C>
	inline bool operator!=(const C* p1, const scoped_ptr<const C>& p2) {
	return p1 != p2.get();
	}

	// Specialization of scoped_ptr for holding arrays.
	//
	// scoped_ptr<C[]> is like scoped_ptr<C>, except that the caller must allocate
	// with new [] and the destructor deletes objects with delete [].
	//
	// As with scoped_ptr<C>, a scoped_ptr<C[]> either points to an array of objects
	// or is NULL. A scoped_ptr<C[]> owns the array that it points to.
	// scoped_ptr<C[]> is thread-compatible, and once you index into it, the
	// returned objects have only the threadsafety guarantees of C.
	//
	// Size: sizeof(scoped_ptr<C[]>) == sizeof(C*)
	template <class C>
	class scoped_ptr<C[]> {
	public:
	// The element type
	typedef C element_type;

	// Constructor. Defaults to intializing with NULL.
	// There is no way to create an uninitialized scoped_ptr.
	// The input parameter must be allocated with new [].
	explicit scoped_ptr(C* p = NULL) : array_(p) { }

	// Destructor. If there is a C object, delete it.
	// We don't need to test ptr_ == NULL because C++ does that for us.
	~scoped_ptr() {
	enum { type_must_be_complete = sizeof(C) };
	delete[] array_;
	}

	// Reset. Deletes the current owned object, if any.
	// Then takes ownership of a new object, if given.
	// this->reset(this->get()) works.
	void reset(C* p = NULL) {
	if (p != array_) {
	enum { type_must_be_complete = sizeof(C) };
	delete[] array_;
	array_ = p;
	}
	}

	// Get one element of the current object.
	// Will assert() if there is no current object, or index i is negative.
	C& operator[](std::ptrdiff_t i) const {
	assert(i >= 0);
	assert(array_ != NULL);
	return array_[i];
	}

	// Get a pointer to the zeroth element of the current object.
	// If there is no current object, return NULL.
	C* get() const {
	return array_;
	}

	// Comparison operators.
	// These return whether a scoped_ptr and a raw pointer refer to
	// the same array, not just to two different but equal arrays.
	bool operator==(const C* p) const { return array_ == p; }
	bool operator!=(const C* p) const { return array_ != p; }

	// Swap two scoped arrays.
	void swap(scoped_ptr& p2) {
	C* tmp = array_;
	array_ = p2.array_;
	p2.array_ = tmp;
	}

	// Release an array.
	// The return value is the current pointer held by this object.
	// If this object holds a NULL pointer, the return value is NULL.
	// After this operation, this object will hold a NULL pointer,
	// and will not own the object any more.
	C* release() {
	C* retVal = array_;
	array_ = NULL;
	return retVal;
	}

	private:
	C* array_;

	// Forbid comparison of different scoped_ptr types.
	template <class C2> bool operator==(scoped_ptr<C2[]> const& p2) const;
	template <class C2> bool operator!=(scoped_ptr<C2[]> const& p2) const;

	DISALLOW_COPY_AND_ASSIGN(scoped_ptr);
	};

	// Free functions
	template <class C>
	inline void swap(scoped_ptr<C[]>& p1, scoped_ptr<C[]>& p2) {
	p1.swap(p2);
	}

	template <class C>
	inline bool operator==(const C* p1, const scoped_ptr<C[]>& p2) {
	return p1 == p2.get();
	}

	template <class C>
	inline bool operator==(const C* p1, const scoped_ptr<const C[]>& p2) {
	return p1 == p2.get();
	}

	template <class C>
	inline bool operator!=(const C* p1, const scoped_ptr<C[]>& p2) {
	return p1 != p2.get();
	}

	template <class C>
	inline bool operator!=(const C* p1, const scoped_ptr<const C[]>& p2) {
	return p1 != p2.get();
	}

	#endif // MOZC_BASE_SCOPED_PTR_H_