forked from OSchip/llvm-project
50 lines
1.1 KiB
C++
50 lines
1.1 KiB
C++
//===----------------------------------------------------------------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is dual licensed under the MIT and the University of Illinois Open
|
|
// Source Licenses. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
// <memory>
|
|
|
|
// weak_ptr
|
|
|
|
// template<class T> void swap(weak_ptr<T>& a, weak_ptr<T>& b)
|
|
|
|
#include <memory>
|
|
#include <cassert>
|
|
|
|
struct A
|
|
{
|
|
static int count;
|
|
|
|
A() {++count;}
|
|
A(const A&) {++count;}
|
|
~A() {--count;}
|
|
};
|
|
|
|
int A::count = 0;
|
|
|
|
int main()
|
|
{
|
|
{
|
|
A* ptr1 = new A;
|
|
A* ptr2 = new A;
|
|
std::shared_ptr<A> p1(ptr1);
|
|
std::weak_ptr<A> w1(p1);
|
|
{
|
|
std::shared_ptr<A> p2(ptr2);
|
|
std::weak_ptr<A> w2(p2);
|
|
swap(w1, w2);
|
|
assert(w1.use_count() == 1);
|
|
assert(w1.lock().get() == ptr2);
|
|
assert(w2.use_count() == 1);
|
|
assert(w2.lock().get() == ptr1);
|
|
assert(A::count == 2);
|
|
}
|
|
}
|
|
assert(A::count == 0);
|
|
}
|