1ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// Copyright 2003 Google Inc. 2ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// All rights reserved. 3ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// 4ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// Redistribution and use in source and binary forms, with or without 5ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// modification, are permitted provided that the following conditions are 6ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// met: 7ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// 8ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// * Redistributions of source code must retain the above copyright 9ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// notice, this list of conditions and the following disclaimer. 10ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// * Redistributions in binary form must reproduce the above 11ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// copyright notice, this list of conditions and the following disclaimer 12ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// in the documentation and/or other materials provided with the 1391037db265ecdd914a26e056cf69207b4f50924ehkuang// distribution. 14ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// * Neither the name of Google Inc. nor the names of its 15ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// contributors may be used to endorse or promote products derived from 16ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// this software without specific prior written permission. 17ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// 18ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 206ac915abcdb404a00d927fe6308a47fcf09d9519hkuang// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 236ac915abcdb404a00d927fe6308a47fcf09d9519hkuang// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 246ac915abcdb404a00d927fe6308a47fcf09d9519hkuang// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 266ac915abcdb404a00d927fe6308a47fcf09d9519hkuang// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 276ac915abcdb404a00d927fe6308a47fcf09d9519hkuang// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 286ac915abcdb404a00d927fe6308a47fcf09d9519hkuang// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// 30ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// Authors: Dan Egnor (egnor@google.com) 31ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// 321184aebb761cbeac9124c37189a80a1a58f04b6bhkuang// A "smart" pointer type with reference tracking. Every pointer to a 331184aebb761cbeac9124c37189a80a1a58f04b6bhkuang// particular object is kept on a circular linked list. When the last pointer 346ac915abcdb404a00d927fe6308a47fcf09d9519hkuang// to an object is destroyed or reassigned, the object is deleted. 355ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang// 365ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang// Used properly, this deletes the object when the last reference goes away. 375ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang// There are several caveats: 385ae7ac49f08a179e4f054d99fcfc9dce78d26e58hkuang// - Like all reference counting schemes, cycles lead to leaks. 39ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// - Each smart pointer is actually two pointers (8 bytes instead of 4). 40ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// - Every time a pointer is assigned, the entire list of pointers to that 41ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// object is traversed. This class is therefore NOT SUITABLE when there 426ac915abcdb404a00d927fe6308a47fcf09d9519hkuang// will often be more than two or three pointers to a particular object. 436ac915abcdb404a00d927fe6308a47fcf09d9519hkuang// - References are only tracked as long as linked_ptr<> objects are copied. 446ac915abcdb404a00d927fe6308a47fcf09d9519hkuang// If a linked_ptr<> is converted to a raw pointer and back, BAD THINGS 456ac915abcdb404a00d927fe6308a47fcf09d9519hkuang// will happen (double deletion). 46ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// 476ac915abcdb404a00d927fe6308a47fcf09d9519hkuang// A good use of this class is storing object references in STL containers. 48ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// You can safely put linked_ptr<> in a vector<>. 496ac915abcdb404a00d927fe6308a47fcf09d9519hkuang// Other uses may not be as good. 506ac915abcdb404a00d927fe6308a47fcf09d9519hkuang// 51ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// Note: If you use an incomplete type with linked_ptr<>, the class 526ac915abcdb404a00d927fe6308a47fcf09d9519hkuang// *containing* linked_ptr<> must have a constructor and destructor (even 53ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// if they do nothing!). 54ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang// 55a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian// Bill Gibbons suggested we use something like this. 56a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian// 57a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian// Thread Safety: 58a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian// Unlike other linked_ptr implementations, in this implementation 59a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian// a linked_ptr object is thread-safe in the sense that: 60a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian// - it's safe to copy linked_ptr objects concurrently, 61a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian// - it's safe to copy *from* a linked_ptr and read its underlying 62a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian// raw pointer (e.g. via get()) concurrently, and 63a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian// - it's safe to write to two linked_ptrs that point to the same 64a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian// shared object concurrently. 65a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian// TODO(wan@google.com): rename this to safe_linked_ptr to avoid 66a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian// confusion with normal linked_ptr. 67a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian 68a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian#ifndef GTEST_INCLUDE_GTEST_INTERNAL_GTEST_LINKED_PTR_H_ 69a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian#define GTEST_INCLUDE_GTEST_INTERNAL_GTEST_LINKED_PTR_H_ 70a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian 71a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian#include <stdlib.h> 72a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian#include <assert.h> 73a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian 74a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian#include "gtest/internal/gtest-port.h" 75a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian 76a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramaniannamespace testing { 77a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramaniannamespace internal { 78a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian 79a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian// Protects copying of all linked_ptr objects. 80a72801d7d92ababb50eecf27a36bd222d031d2feVignesh VenkatasubramanianGTEST_API_ GTEST_DECLARE_STATIC_MUTEX_(g_linked_ptr_mutex); 81a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian 82a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian// This is used internally by all instances of linked_ptr<>. It needs to be 83a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian// a non-template class because different types of linked_ptr<> can refer to 84a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian// the same object (linked_ptr<Superclass>(obj) vs linked_ptr<Subclass>(obj)). 85a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian// So, it needs to be possible for different types of linked_ptr to participate 86a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian// in the same circular linked list, so we need a single class type here. 87a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian// 88a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian// DO NOT USE THIS CLASS DIRECTLY YOURSELF. Use linked_ptr<T>. 89a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanianclass linked_ptr_internal { 90a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian public: 91a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian // Create a new circle that includes only this instance. 92a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian void join_new() { 93a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian next_ = this; 94a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian } 95a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian 96a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian // Many linked_ptr operations may change p.link_ for some linked_ptr 97a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian // variable p in the same circle as this object. Therefore we need 98a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian // to prevent two such operations from occurring concurrently. 99a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian // 100a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian // Note that different types of linked_ptr objects can coexist in a 101a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian // circle (e.g. linked_ptr<Base>, linked_ptr<Derived1>, and 102a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian // linked_ptr<Derived2>). Therefore we must use a single mutex to 103a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian // protect all linked_ptr objects. This can create serious 104a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian // contention in production code, but is acceptable in a testing 105a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian // framework. 106a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian 107a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian // Join an existing circle. 1086ac915abcdb404a00d927fe6308a47fcf09d9519hkuang // L < g_linked_ptr_mutex 1096ac915abcdb404a00d927fe6308a47fcf09d9519hkuang void join(linked_ptr_internal const* ptr) { 1106ac915abcdb404a00d927fe6308a47fcf09d9519hkuang MutexLock lock(&g_linked_ptr_mutex); 1116ac915abcdb404a00d927fe6308a47fcf09d9519hkuang 1126ac915abcdb404a00d927fe6308a47fcf09d9519hkuang linked_ptr_internal const* p = ptr; 1136ac915abcdb404a00d927fe6308a47fcf09d9519hkuang while (p->next_ != ptr) p = p->next_; 114a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian p->next_ = this; 115a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian next_ = ptr; 1169b35249446b07f40ac5fcc3205f2c048616efacchkuang } 1179b35249446b07f40ac5fcc3205f2c048616efacchkuang 1189b35249446b07f40ac5fcc3205f2c048616efacchkuang // Leave whatever circle we're part of. Returns true if we were the 1199b35249446b07f40ac5fcc3205f2c048616efacchkuang // last member of the circle. Once this is done, you can join() another. 1209b35249446b07f40ac5fcc3205f2c048616efacchkuang // L < g_linked_ptr_mutex 1219b35249446b07f40ac5fcc3205f2c048616efacchkuang bool depart() { 1229b35249446b07f40ac5fcc3205f2c048616efacchkuang MutexLock lock(&g_linked_ptr_mutex); 123b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian 1249b35249446b07f40ac5fcc3205f2c048616efacchkuang if (next_ == this) return true; 1259b35249446b07f40ac5fcc3205f2c048616efacchkuang linked_ptr_internal const* p = next_; 1269b35249446b07f40ac5fcc3205f2c048616efacchkuang while (p->next_ != this) p = p->next_; 1279b35249446b07f40ac5fcc3205f2c048616efacchkuang p->next_ = next_; 128a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian return false; 1296ac915abcdb404a00d927fe6308a47fcf09d9519hkuang } 1309b35249446b07f40ac5fcc3205f2c048616efacchkuang 1319b35249446b07f40ac5fcc3205f2c048616efacchkuang private: 1329b35249446b07f40ac5fcc3205f2c048616efacchkuang mutable linked_ptr_internal const* next_; 1339b35249446b07f40ac5fcc3205f2c048616efacchkuang}; 1349b35249446b07f40ac5fcc3205f2c048616efacchkuang 1359b35249446b07f40ac5fcc3205f2c048616efacchkuangtemplate <typename T> 136a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanianclass linked_ptr { 1379b35249446b07f40ac5fcc3205f2c048616efacchkuang public: 1389b35249446b07f40ac5fcc3205f2c048616efacchkuang typedef T element_type; 1399b35249446b07f40ac5fcc3205f2c048616efacchkuang 1406ac915abcdb404a00d927fe6308a47fcf09d9519hkuang // Take over ownership of a raw pointer. This should happen as soon as 1416ac915abcdb404a00d927fe6308a47fcf09d9519hkuang // possible after the object is created. 1426ac915abcdb404a00d927fe6308a47fcf09d9519hkuang explicit linked_ptr(T* ptr = NULL) { capture(ptr); } 1436ac915abcdb404a00d927fe6308a47fcf09d9519hkuang ~linked_ptr() { depart(); } 1446ac915abcdb404a00d927fe6308a47fcf09d9519hkuang 1456ac915abcdb404a00d927fe6308a47fcf09d9519hkuang // Copy an existing linked_ptr<>, adding ourselves to the list of references. 1466ac915abcdb404a00d927fe6308a47fcf09d9519hkuang template <typename U> linked_ptr(linked_ptr<U> const& ptr) { copy(&ptr); } 1476ac915abcdb404a00d927fe6308a47fcf09d9519hkuang linked_ptr(linked_ptr const& ptr) { // NOLINT 1486ac915abcdb404a00d927fe6308a47fcf09d9519hkuang assert(&ptr != this); 1496ac915abcdb404a00d927fe6308a47fcf09d9519hkuang copy(&ptr); 1506ac915abcdb404a00d927fe6308a47fcf09d9519hkuang } 1516ac915abcdb404a00d927fe6308a47fcf09d9519hkuang 1526ac915abcdb404a00d927fe6308a47fcf09d9519hkuang // Assignment releases the old value and acquires the new. 1536ac915abcdb404a00d927fe6308a47fcf09d9519hkuang template <typename U> linked_ptr& operator=(linked_ptr<U> const& ptr) { 1546ac915abcdb404a00d927fe6308a47fcf09d9519hkuang depart(); 1559b35249446b07f40ac5fcc3205f2c048616efacchkuang copy(&ptr); 1569b35249446b07f40ac5fcc3205f2c048616efacchkuang return *this; 1579b35249446b07f40ac5fcc3205f2c048616efacchkuang } 1589b35249446b07f40ac5fcc3205f2c048616efacchkuang 1599b35249446b07f40ac5fcc3205f2c048616efacchkuang linked_ptr& operator=(linked_ptr const& ptr) { 1609b35249446b07f40ac5fcc3205f2c048616efacchkuang if (&ptr != this) { 1619b35249446b07f40ac5fcc3205f2c048616efacchkuang depart(); 1621184aebb761cbeac9124c37189a80a1a58f04b6bhkuang copy(&ptr); 1631184aebb761cbeac9124c37189a80a1a58f04b6bhkuang } 1641184aebb761cbeac9124c37189a80a1a58f04b6bhkuang return *this; 1651184aebb761cbeac9124c37189a80a1a58f04b6bhkuang } 1661184aebb761cbeac9124c37189a80a1a58f04b6bhkuang 1676ac915abcdb404a00d927fe6308a47fcf09d9519hkuang // Smart pointer members. 168ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang void reset(T* ptr = NULL) { 1691184aebb761cbeac9124c37189a80a1a58f04b6bhkuang depart(); 170ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang capture(ptr); 171b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian } 172b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian T* get() const { return value_; } 173b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian T* operator->() const { return value_; } 174b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian T& operator*() const { return *value_; } 175ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang 176ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang bool operator==(T* p) const { return value_ == p; } 177ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang bool operator!=(T* p) const { return value_ != p; } 178b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian template <typename U> 179b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian bool operator==(linked_ptr<U> const& ptr) const { 180ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang return value_ == ptr.get(); 181b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian } 1821184aebb761cbeac9124c37189a80a1a58f04b6bhkuang template <typename U> 183b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian bool operator!=(linked_ptr<U> const& ptr) const { 184ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang return value_ != ptr.get(); 185ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang } 1861184aebb761cbeac9124c37189a80a1a58f04b6bhkuang 187b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian private: 188ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang template <typename U> 189ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang friend class linked_ptr; 1901184aebb761cbeac9124c37189a80a1a58f04b6bhkuang 191ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang T* value_; 1926ac915abcdb404a00d927fe6308a47fcf09d9519hkuang linked_ptr_internal link_; 1931184aebb761cbeac9124c37189a80a1a58f04b6bhkuang 1941184aebb761cbeac9124c37189a80a1a58f04b6bhkuang void depart() { 1951184aebb761cbeac9124c37189a80a1a58f04b6bhkuang if (link_.depart()) delete value_; 196ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang } 1971184aebb761cbeac9124c37189a80a1a58f04b6bhkuang 198a72801d7d92ababb50eecf27a36bd222d031d2feVignesh Venkatasubramanian void capture(T* ptr) { 1991184aebb761cbeac9124c37189a80a1a58f04b6bhkuang value_ = ptr; 200ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang link_.join_new(); 201ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang } 2026ac915abcdb404a00d927fe6308a47fcf09d9519hkuang 2036ac915abcdb404a00d927fe6308a47fcf09d9519hkuang template <typename U> void copy(linked_ptr<U> const* ptr) { 2046ac915abcdb404a00d927fe6308a47fcf09d9519hkuang value_ = ptr->get(); 2056ac915abcdb404a00d927fe6308a47fcf09d9519hkuang if (value_) 2066ac915abcdb404a00d927fe6308a47fcf09d9519hkuang link_.join(&ptr->link_); 2076ac915abcdb404a00d927fe6308a47fcf09d9519hkuang else 2086ac915abcdb404a00d927fe6308a47fcf09d9519hkuang link_.join_new(); 2096ac915abcdb404a00d927fe6308a47fcf09d9519hkuang } 2106ac915abcdb404a00d927fe6308a47fcf09d9519hkuang}; 2116ac915abcdb404a00d927fe6308a47fcf09d9519hkuang 2126ac915abcdb404a00d927fe6308a47fcf09d9519hkuangtemplate<typename T> inline 2136ac915abcdb404a00d927fe6308a47fcf09d9519hkuangbool operator==(T* ptr, const linked_ptr<T>& x) { 2146ac915abcdb404a00d927fe6308a47fcf09d9519hkuang return ptr == x.get(); 215ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang} 216ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang 217ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuangtemplate<typename T> inline 2181184aebb761cbeac9124c37189a80a1a58f04b6bhkuangbool operator!=(T* ptr, const linked_ptr<T>& x) { 219ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang return ptr != x.get(); 220ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang} 221ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang 2221184aebb761cbeac9124c37189a80a1a58f04b6bhkuang// A function to convert T* into linked_ptr<T> 2231184aebb761cbeac9124c37189a80a1a58f04b6bhkuang// Doing e.g. make_linked_ptr(new FooBarBaz<type>(arg)) is a shorter notation 224b08e2e23eec181e9951df33cd704ac294c5407b6Vignesh Venkatasubramanian// for linked_ptr<FooBarBaz<type> >(new FooBarBaz<type>(arg)) 225ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuangtemplate <typename T> 226ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuanglinked_ptr<T> make_linked_ptr(T* ptr) { 227ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang return linked_ptr<T>(ptr); 2281184aebb761cbeac9124c37189a80a1a58f04b6bhkuang} 2291184aebb761cbeac9124c37189a80a1a58f04b6bhkuang 230ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang} // namespace internal 231ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang} // namespace testing 232ba164dffc5a6795bce97fae02b51ccf3330e15e4hkuang 23391037db265ecdd914a26e056cf69207b4f50924ehkuang#endif // GTEST_INCLUDE_GTEST_INTERNAL_GTEST_LINKED_PTR_H_ 2341184aebb761cbeac9124c37189a80a1a58f04b6bhkuang