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// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc. All rights reserved.
// https://developers.google.com/protocol-buffers/
//
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//
// * 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
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// distribution.
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//
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#ifndef GOOGLE_PROTOBUF_STUBS_SCOPED_PTR_H_
#define GOOGLE_PROTOBUF_STUBS_SCOPED_PTR_H_
#include <google/protobuf/stubs/port.h>
namespace google {
namespace protobuf {
// ===================================================================
// from google3/base/scoped_ptr.h
namespace internal {
// This is an implementation designed to match the anticipated future TR2
// implementation of the scoped_ptr class, and its closely-related brethren,
// scoped_array, scoped_ptr_malloc, and make_scoped_ptr.
template <class C> class scoped_ptr;
template <class C> class scoped_array;
// 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.
//
// 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 initializing 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 two scoped_ptr refer to the same object, not just to
// two different but equal objects.
bool operator==(C* p) const { return ptr_ == p; }
bool operator!=(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 evil constructors
scoped_ptr(const scoped_ptr&);
void operator=(const scoped_ptr&);
};
// scoped_array<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_array<C> either points to an object
// or is NULL. A scoped_array<C> owns the object that it points to.
//
// Size: sizeof(scoped_array<C>) == sizeof(C*)
template <class C>
class scoped_array {
public:
// The element type
typedef C element_type;
// Constructor. Defaults to initializing with NULL.
// There is no way to create an uninitialized scoped_array.
// The input parameter must be allocated with new [].
explicit scoped_array(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_array() {
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 two scoped_array refer to the same object, not just to
// two different but equal objects.
bool operator==(C* p) const { return array_ == p; }
bool operator!=(C* p) const { return array_ != p; }
// Swap two scoped arrays.
void swap(scoped_array& 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_array types.
template <class C2> bool operator==(scoped_array<C2> const& p2) const;
template <class C2> bool operator!=(scoped_array<C2> const& p2) const;
// Disallow evil constructors
scoped_array(const scoped_array&);
void operator=(const scoped_array&);
};
} // namespace internal
// We made these internal so that they would show up as such in the docs,
// but we don't want to stick "internal::" in front of them everywhere.
using internal::scoped_ptr;
using internal::scoped_array;
} // namespace protobuf
} // namespace google
#endif // GOOGLE_PROTOBUF_STUBS_SCOPED_PTR_H_