forked from OSchip/llvm-project
59 lines
1.3 KiB
C++
59 lines
1.3 KiB
C++
//===----------------------------------------------------------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is dual licensed under the MIT and the University of Illinois Open
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// Source Licenses. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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// <memory>
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// weak_ptr
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// shared_ptr<T> lock() const;
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#include <memory>
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#include <cassert>
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struct A
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{
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static int count;
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A() {++count;}
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A(const A&) {++count;}
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~A() {--count;}
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};
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int A::count = 0;
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int main()
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{
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{
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std::weak_ptr<A> wp;
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std::shared_ptr<A> sp = wp.lock();
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assert(sp.use_count() == 0);
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assert(sp.get() == 0);
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assert(A::count == 0);
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}
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{
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std::shared_ptr<A> sp0(new A);
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std::weak_ptr<A> wp(sp0);
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std::shared_ptr<A> sp = wp.lock();
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assert(sp.use_count() == 2);
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assert(sp.get() == sp0.get());
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assert(A::count == 1);
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}
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assert(A::count == 0);
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{
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std::shared_ptr<A> sp0(new A);
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std::weak_ptr<A> wp(sp0);
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sp0.reset();
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std::shared_ptr<A> sp = wp.lock();
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assert(sp.use_count() == 0);
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assert(sp.get() == 0);
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assert(A::count == 0);
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}
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assert(A::count == 0);
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}
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