| Index: base/memory/scoped_ptr.h
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| diff --git a/base/memory/scoped_ptr.h b/base/memory/scoped_ptr.h
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| new file mode 100644
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| index 0000000000000000000000000000000000000000..1474123f205e814d98d62aa16f59dbe29dd42322
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| --- /dev/null
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| +++ b/base/memory/scoped_ptr.h
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| @@ -0,0 +1,383 @@
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| +// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
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| +// Use of this source code is governed by a BSD-style license that can be
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| +// found in the LICENSE file.
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| +
|
| +// Scopers help you manage ownership of a pointer, helping you easily manage the
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| +// a pointer within a scope, and automatically destroying the pointer at the
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| +// end of a scope. There are two main classes you will use, which correspond
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| +// to the operators new/delete and new[]/delete[].
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| +//
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| +// Example usage (scoped_ptr):
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| +// {
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| +// scoped_ptr<Foo> foo(new Foo("wee"));
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| +// } // foo goes out of scope, releasing the pointer with it.
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| +//
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| +// {
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| +// scoped_ptr<Foo> foo; // No pointer managed.
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| +// foo.reset(new Foo("wee")); // Now a pointer is managed.
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| +// foo.reset(new Foo("wee2")); // Foo("wee") was destroyed.
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| +// foo.reset(new Foo("wee3")); // Foo("wee2") was destroyed.
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| +// foo->Method(); // Foo::Method() called.
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| +// foo.get()->Method(); // Foo::Method() called.
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| +// SomeFunc(foo.release()); // SomeFunc takes ownership, foo no longer
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| +// // manages a pointer.
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| +// foo.reset(new Foo("wee4")); // foo manages a pointer again.
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| +// foo.reset(); // Foo("wee4") destroyed, foo no longer
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| +// // manages a pointer.
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| +// } // foo wasn't managing a pointer, so nothing was destroyed.
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| +//
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| +// Example usage (scoped_array):
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| +// {
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| +// scoped_array<Foo> foo(new Foo[100]);
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| +// foo.get()->Method(); // Foo::Method on the 0th element.
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| +// foo[10].Method(); // Foo::Method on the 10th element.
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| +// }
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| +
|
| +#ifndef BASE_MEMORY_SCOPED_PTR_H_
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| +#define BASE_MEMORY_SCOPED_PTR_H_
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| +#pragma once
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| +
|
| +// This is an implementation designed to match the anticipated future TR2
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| +// implementation of the scoped_ptr class, and its closely-related brethren,
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| +// scoped_array, scoped_ptr_malloc.
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| +
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| +#include <assert.h>
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| +#include <stddef.h>
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| +#include <stdlib.h>
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| +
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| +#include "base/compiler_specific.h"
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| +
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| +// A scoped_ptr<T> is like a T*, except that the destructor of scoped_ptr<T>
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| +// automatically deletes the pointer it holds (if any).
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| +// That is, scoped_ptr<T> owns the T object that it points to.
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| +// Like a T*, a scoped_ptr<T> may hold either NULL or a pointer to a T object.
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| +// Also like T*, scoped_ptr<T> is thread-compatible, and once you
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| +// dereference it, you get the threadsafety guarantees of T.
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| +//
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| +// The size of a scoped_ptr is small:
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| +// sizeof(scoped_ptr<C>) == sizeof(C*)
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| +template <class C>
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| +class scoped_ptr {
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| + public:
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| +
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| + // The element type
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| + typedef C element_type;
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| +
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| + // Constructor. Defaults to initializing with NULL.
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| + // There is no way to create an uninitialized scoped_ptr.
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| + // The input parameter must be allocated with new.
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| + explicit scoped_ptr(C* p = NULL) : ptr_(p) { }
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| +
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| + // Destructor. If there is a C object, delete it.
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| + // We don't need to test ptr_ == NULL because C++ does that for us.
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| + ~scoped_ptr() {
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| + enum { type_must_be_complete = sizeof(C) };
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| + delete ptr_;
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| + }
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| +
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| + // Reset. Deletes the current owned object, if any.
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| + // Then takes ownership of a new object, if given.
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| + // this->reset(this->get()) works.
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| + void reset(C* p = NULL) {
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| + if (p != ptr_) {
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| + enum { type_must_be_complete = sizeof(C) };
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| + delete ptr_;
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| + ptr_ = p;
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| + }
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| + }
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| +
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| + // Accessors to get the owned object.
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| + // operator* and operator-> will assert() if there is no current object.
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| + C& operator*() const {
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| + assert(ptr_ != NULL);
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| + return *ptr_;
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| + }
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| + C* operator->() const {
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| + assert(ptr_ != NULL);
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| + return ptr_;
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| + }
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| + C* get() const { return ptr_; }
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| +
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| + // Comparison operators.
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| + // These return whether two scoped_ptr refer to the same object, not just to
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| + // two different but equal objects.
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| + bool operator==(C* p) const { return ptr_ == p; }
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| + bool operator!=(C* p) const { return ptr_ != p; }
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| +
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| + // Swap two scoped pointers.
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| + void swap(scoped_ptr& p2) {
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| + C* tmp = ptr_;
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| + ptr_ = p2.ptr_;
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| + p2.ptr_ = tmp;
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| + }
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| +
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| + // Release a pointer.
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| + // The return value is the current pointer held by this object.
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| + // If this object holds a NULL pointer, the return value is NULL.
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| + // After this operation, this object will hold a NULL pointer,
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| + // and will not own the object any more.
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| + C* release() WARN_UNUSED_RESULT {
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| + C* retVal = ptr_;
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| + ptr_ = NULL;
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| + return retVal;
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| + }
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| +
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| + private:
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| + C* ptr_;
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| +
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| + // Forbid comparison of scoped_ptr types. If C2 != C, it totally doesn't
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| + // make sense, and if C2 == C, it still doesn't make sense because you should
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| + // never have the same object owned by two different scoped_ptrs.
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| + template <class C2> bool operator==(scoped_ptr<C2> const& p2) const;
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| + template <class C2> bool operator!=(scoped_ptr<C2> const& p2) const;
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| +
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| + // Disallow evil constructors
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| + scoped_ptr(const scoped_ptr&);
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| + void operator=(const scoped_ptr&);
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| +};
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| +
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| +// Free functions
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| +template <class C>
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| +void swap(scoped_ptr<C>& p1, scoped_ptr<C>& p2) {
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| + p1.swap(p2);
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| +}
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| +
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| +template <class C>
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| +bool operator==(C* p1, const scoped_ptr<C>& p2) {
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| + return p1 == p2.get();
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| +}
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| +
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| +template <class C>
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| +bool operator!=(C* p1, const scoped_ptr<C>& p2) {
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| + return p1 != p2.get();
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| +}
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| +
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| +// scoped_array<C> is like scoped_ptr<C>, except that the caller must allocate
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| +// with new [] and the destructor deletes objects with delete [].
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| +//
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| +// As with scoped_ptr<C>, a scoped_array<C> either points to an object
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| +// or is NULL. A scoped_array<C> owns the object that it points to.
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| +// scoped_array<T> is thread-compatible, and once you index into it,
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| +// the returned objects have only the threadsafety guarantees of T.
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| +//
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| +// Size: sizeof(scoped_array<C>) == sizeof(C*)
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| +template <class C>
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| +class scoped_array {
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| + public:
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| +
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| + // The element type
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| + typedef C element_type;
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| +
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| + // Constructor. Defaults to intializing with NULL.
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| + // There is no way to create an uninitialized scoped_array.
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| + // The input parameter must be allocated with new [].
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| + explicit scoped_array(C* p = NULL) : array_(p) { }
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| +
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| + // Destructor. If there is a C object, delete it.
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| + // We don't need to test ptr_ == NULL because C++ does that for us.
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| + ~scoped_array() {
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| + enum { type_must_be_complete = sizeof(C) };
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| + delete[] array_;
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| + }
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| +
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| + // Reset. Deletes the current owned object, if any.
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| + // Then takes ownership of a new object, if given.
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| + // this->reset(this->get()) works.
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| + void reset(C* p = NULL) {
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| + if (p != array_) {
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| + enum { type_must_be_complete = sizeof(C) };
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| + delete[] array_;
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| + array_ = p;
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| + }
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| + }
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| +
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| + // Get one element of the current object.
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| + // Will assert() if there is no current object, or index i is negative.
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| + C& operator[](ptrdiff_t i) const {
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| + assert(i >= 0);
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| + assert(array_ != NULL);
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| + return array_[i];
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| + }
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| +
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| + // Get a pointer to the zeroth element of the current object.
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| + // If there is no current object, return NULL.
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| + C* get() const {
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| + return array_;
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| + }
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| +
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| + // Comparison operators.
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| + // These return whether two scoped_array refer to the same object, not just to
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| + // two different but equal objects.
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| + bool operator==(C* p) const { return array_ == p; }
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| + bool operator!=(C* p) const { return array_ != p; }
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| +
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| + // Swap two scoped arrays.
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| + void swap(scoped_array& p2) {
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| + C* tmp = array_;
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| + array_ = p2.array_;
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| + p2.array_ = tmp;
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| + }
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| +
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| + // Release an array.
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| + // The return value is the current pointer held by this object.
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| + // If this object holds a NULL pointer, the return value is NULL.
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| + // After this operation, this object will hold a NULL pointer,
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| + // and will not own the object any more.
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| + C* release() WARN_UNUSED_RESULT {
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| + C* retVal = array_;
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| + array_ = NULL;
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| + return retVal;
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| + }
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| +
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| + private:
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| + C* array_;
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| +
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| + // Forbid comparison of different scoped_array types.
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| + template <class C2> bool operator==(scoped_array<C2> const& p2) const;
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| + template <class C2> bool operator!=(scoped_array<C2> const& p2) const;
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| +
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| + // Disallow evil constructors
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| + scoped_array(const scoped_array&);
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| + void operator=(const scoped_array&);
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| +};
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| +
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| +// Free functions
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| +template <class C>
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| +void swap(scoped_array<C>& p1, scoped_array<C>& p2) {
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| + p1.swap(p2);
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| +}
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| +
|
| +template <class C>
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| +bool operator==(C* p1, const scoped_array<C>& p2) {
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| + return p1 == p2.get();
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| +}
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| +
|
| +template <class C>
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| +bool operator!=(C* p1, const scoped_array<C>& p2) {
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| + return p1 != p2.get();
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| +}
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| +
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| +// This class wraps the c library function free() in a class that can be
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| +// passed as a template argument to scoped_ptr_malloc below.
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| +class ScopedPtrMallocFree {
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| + public:
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| + inline void operator()(void* x) const {
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| + free(x);
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| + }
|
| +};
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| +
|
| +// scoped_ptr_malloc<> is similar to scoped_ptr<>, but it accepts a
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| +// second template argument, the functor used to free the object.
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| +
|
| +template<class C, class FreeProc = ScopedPtrMallocFree>
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| +class scoped_ptr_malloc {
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| + public:
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| +
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| + // The element type
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| + typedef C element_type;
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| +
|
| + // Constructor. Defaults to initializing with NULL.
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| + // There is no way to create an uninitialized scoped_ptr.
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| + // The input parameter must be allocated with an allocator that matches the
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| + // Free functor. For the default Free functor, this is malloc, calloc, or
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| + // realloc.
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| + explicit scoped_ptr_malloc(C* p = NULL): ptr_(p) {}
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| +
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| + // Destructor. If there is a C object, call the Free functor.
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| + ~scoped_ptr_malloc() {
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| + free_(ptr_);
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| + }
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| +
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| + // Reset. Calls the Free functor on the current owned object, if any.
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| + // Then takes ownership of a new object, if given.
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| + // this->reset(this->get()) works.
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| + void reset(C* p = NULL) {
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| + if (ptr_ != p) {
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| + free_(ptr_);
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| + ptr_ = p;
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| + }
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| + }
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| +
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| + // Get the current object.
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| + // operator* and operator-> will cause an assert() failure if there is
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| + // no current object.
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| + C& operator*() const {
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| + assert(ptr_ != NULL);
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| + return *ptr_;
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| + }
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| +
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| + C* operator->() const {
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| + assert(ptr_ != NULL);
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| + return ptr_;
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| + }
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| +
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| + C* get() const {
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| + return ptr_;
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| + }
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| +
|
| + // Comparison operators.
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| + // These return whether a scoped_ptr_malloc and a plain pointer refer
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| + // to the same object, not just to two different but equal objects.
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| + // For compatibility with the boost-derived implementation, these
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| + // take non-const arguments.
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| + bool operator==(C* p) const {
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| + return ptr_ == p;
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| + }
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| +
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| + bool operator!=(C* p) const {
|
| + return ptr_ != p;
|
| + }
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| +
|
| + // Swap two scoped pointers.
|
| + void swap(scoped_ptr_malloc & b) {
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| + C* tmp = b.ptr_;
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| + b.ptr_ = ptr_;
|
| + 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,
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| + // and will not own the object any more.
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| + C* release() WARN_UNUSED_RESULT {
|
| + C* tmp = ptr_;
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| + ptr_ = NULL;
|
| + return tmp;
|
| + }
|
| +
|
| + private:
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| + C* ptr_;
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| +
|
| + // no reason to use these: each scoped_ptr_malloc should have its own object
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| + template <class C2, class GP>
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| + bool operator==(scoped_ptr_malloc<C2, GP> const& p) const;
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| + template <class C2, class GP>
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| + bool operator!=(scoped_ptr_malloc<C2, GP> const& p) const;
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| +
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| + static FreeProc const free_;
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| +
|
| + // Disallow evil constructors
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| + scoped_ptr_malloc(const scoped_ptr_malloc&);
|
| + void operator=(const scoped_ptr_malloc&);
|
| +};
|
| +
|
| +template<class C, class FP>
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| +FP const scoped_ptr_malloc<C, FP>::free_ = FP();
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| +
|
| +template<class C, class FP> inline
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| +void swap(scoped_ptr_malloc<C, FP>& a, scoped_ptr_malloc<C, FP>& b) {
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| + a.swap(b);
|
| +}
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| +
|
| +template<class C, class FP> inline
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| +bool operator==(C* p, const scoped_ptr_malloc<C, FP>& b) {
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| + return p == b.get();
|
| +}
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| +
|
| +template<class C, class FP> inline
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| +bool operator!=(C* p, const scoped_ptr_malloc<C, FP>& b) {
|
| + return p != b.get();
|
| +}
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| +
|
| +#endif // BASE_MEMORY_SCOPED_PTR_H_
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|
|