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+// Copyright 2013 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.
+
+// This is a copy of breakpad's standalone scoped_ptr, which has been
+// renamed to nonstd::unique_ptr, and from which more complicated classes
+// have been removed. The reset() method has also been tweaked to more
+// closely match c++11, and an implicit conversion to bool has been added.
+
+// Scopers help you manage ownership of a pointer, helping you easily manage the
+// a pointer within a scope, and automatically destroying the pointer at the
+// end of a scope.
+//
+// Example usage (unique_ptr):
+// {
+// unique_ptr<Foo> foo(new Foo("wee"));
+// } // foo goes out of scope, releasing the pointer with it.
+//
+// {
+// unique_ptr<Foo> foo; // No pointer managed.
+// foo.reset(new Foo("wee")); // Now a pointer is managed.
+// foo.reset(new Foo("wee2")); // Foo("wee") was destroyed.
+// foo.reset(new Foo("wee3")); // Foo("wee2") was destroyed.
+// foo->Method(); // Foo::Method() called.
+// foo.get()->Method(); // Foo::Method() called.
+// SomeFunc(foo.release()); // SomeFunc takes ownership, foo no longer
+// // manages a pointer.
+// foo.reset(new Foo("wee4")); // foo manages a pointer again.
+// foo.reset(); // Foo("wee4") destroyed, foo no longer
+// // manages a pointer.
+// } // foo wasn't managing a pointer, so nothing was destroyed.
+
+#ifndef NONSTD_UNIQUE_PTR_H_
+#define NONSTD_UNIQUE_PTR_H_
+
+// This is an implementation designed to match the anticipated future TR2
+// implementation of the unique_ptr class.
+
+#include <assert.h>
+#include <stddef.h>
+#include <stdlib.h>
+
+namespace nonstd {
+
+// A unique_ptr<T> is like a T*, except that the destructor of unique_ptr<T>
+// automatically deletes the pointer it holds (if any).
+// That is, unique_ptr<T> owns the T object that it points to.
+// Like a T*, a unique_ptr<T> may hold either NULL or a pointer to a T object.
+// Also like T*, unique_ptr<T> is thread-compatible, and once you
+// dereference it, you get the threadsafety guarantees of T.
+//
+// The size of a unique_ptr is small:
+// sizeof(unique_ptr<C>) == sizeof(C*)
+template <class C>
+class unique_ptr {
+ public:
+
+ // The element type
+ typedef C element_type;
+
+ // Constructor. Defaults to initializing with NULL.
+ // There is no way to create an uninitialized unique_ptr.
+ // The input parameter must be allocated with new.
+ explicit unique_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.
+ ~unique_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) };
+ C* old_ptr = ptr_;
+ ptr_ = p;
+ delete old_ptr;
+ }
+ }
+
+ // 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 unique_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(unique_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;
+ }
+
+ // Allow promotion to bool for conditional statements.
+ operator bool() const { return ptr_ != NULL; }
+
+ private:
+ C* ptr_;
+
+ // Forbid comparison of unique_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 unique_ptrs.
+ template <class C2> bool operator==(unique_ptr<C2> const& p2) const;
+ template <class C2> bool operator!=(unique_ptr<C2> const& p2) const;
+
+ // Disallow evil constructors
+ unique_ptr(const unique_ptr&);
+ void operator=(const unique_ptr&);
+};
+
+// Free functions
+template <class C>
+void swap(unique_ptr<C>& p1, unique_ptr<C>& p2) {
+ p1.swap(p2);
+}
+
+template <class C>
+bool operator==(C* p1, const unique_ptr<C>& p2) {
+ return p1 == p2.get();
+}
+
+template <class C>
+bool operator!=(C* p1, const unique_ptr<C>& p2) {
+ return p1 != p2.get();
+}
+
+} // namespace nonstd
+
+#endif // NONSTD_UNIQUE_PTR_H_